| **LOANS AND ALLOWANCE FOR CREDIT LOSSES (As Restated) (Consumer Lending Asset Quality Indicators - FICO and CLTV Range) (Details) - Consumer - USD ($) $ in Thousands** | Dec. 31, 2015 | Dec. 31, 2014 |
|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------|---------------|---------------|
| Residential Mortgages(1)(3)                                                                                                                                             |          |          |
| **Loans Receivable [Line Items]**                                                                                                                                       |          |          |
| Financing receivables                                                                                                                                                   | $ 6,467,755   | $ 6,969,309   |
| Home Equity Loans and Lines of Credit(2)                                                                                                                                |          |          |
| **Loans Receivable [Line Items]**                                                                                                                                       |          |          |
| Financing receivables                                                                                                                                                   | 6,151,232     | 6,211,298     |
| LTV not applicable | Residential Mortgages(1)(3)                                                                                                                        |          |          |
| **Loans Receivable [Line Items]**                                                                                                                                       |          |          |
| Financing receivables                                                                                                                                                   | 462,640       | 437,972       |
| LTV not applicable | Home Equity Loans and Lines of Credit(2)                                                                                                           |          |          |
| **Loans Receivable [Line Items]**                                                                                                                                       |          |          |
| Financing receivables                                                                                                                                                   | 286,419       | 324,204       |
| LTV less than or equal to 70% | Residential Mortgages(1)(3)                                                                                                             |          |          |
| **Loans Receivable [Line Items]**                                                                                                                                       |          |          |
| Financing receivables                                                                                                                                                   | 3,842,373     | 4,368,075     |
| LTV less than or equal to 70% | Home Equity Loans and Lines of Credit(2)                                                                                                |          |          |
| **Loans Receivable [Line Items]**                                                                                                                                       |          |          |
| Financing receivables                                                                                                                                                   | 3,241,188     | 3,493,788     |
| LTV of 70.01% to 80% | Residential Mortgages(1)(3)                                                                                                                      |          |          |
| **Loans Receivable [Line Items]**                                                                                                                                       |          |          |
| Financing receivables                                                                                                                                                   | 1,440,194     | 1,294,983     |
| LTV of 70.01% to 90% | Home Equity Loans and Lines of Credit(2)                                                                                                         |          |          |
| **Loans Receivable [Line Items]**                                                                                                                                       |          |          |
| Financing receivables                                                                                                                                                   | 2,088,030     | 1,843,574     |
| LTV of 80.01% to 90% | Residential Mortgages(1)(3)                                                                                                                      |          |          |
| **Loans Receivable [Line Items]**                                                                                                                                       |          |          |
| Financing receivables                                                                                                                                                   | 336,893       | 396,356       |
| LTV of 90.01% to 100% | Residential Mortgages(1)(3)                                                                                                                     |          |          |
| **Loans Receivable [Line Items]**                                                                                                                                       |          |          |
| Financing receivables                                                                                                                                                   | 227,494       | 215,803       |
| LTV of 90.01% to 110% | Home Equity Loans and Lines of Credit(2)                                                                                                        |          |          |
| **Loans Receivable [Line Items]**                                                                                                                                       |          |          |
| Financing receivables                                                                                                                                                   | 332,064       | 333,198       |
| LTV of 100.01% to 110% | Residential Mortgages(1)(3)                                                                                                                    |          |          |
| **Loans Receivable [Line Items]**                                                                                                                                       |          |          |
| Financing receivables                                                                                                                                                   | 64,578        | 90,395        |
| LTV greater than 110% | Residential Mortgages(1)(3)                                                                                                                     |          |          |
| **Loans Receivable [Line Items]**                                                                                                                                       |          |          |
| Financing receivables                                                                                                                                                   | 93,583        | 165,725       |
| LTV greater than 110% | Home Equity Loans and Lines of Credit(2)                                                                                                        |          |          |
| **Loans Receivable [Line Items]**                                                                                                                                       |          |          |
| Financing receivables                                                                                                                                                   | 203,531       | 216,534       |
| FICO score not applicable | Residential Mortgages(1)(3)                                                                                                                 |          |          |
| **Loans Receivable [Line Items]**                                                                                                                                       |          |          |
| Financing receivables                                                                                                                                                   | 476,858       | 476,269       |
| FICO score not applicable | Home Equity Loans and Lines of Credit(2)                                                                                                    |          |          |
| **Loans Receivable [Line Items]**                                                                                                                                       |          |          |
| Financing receivables                                                                                                                                                   | 193,074       | 221,219       |
| FICO score not applicable | LTV not applicable | Residential Mortgages(1)(3)                                                                                            |          |          |
| **Loans Receivable [Line Items]**                                                                                                                                       |          |          |
| Financing receivables                                                                                                                                                   | 461,839       | 437,215       |
| FICO score not applicable | LTV not applicable | Home Equity Loans and Lines of Credit(2)                                                                               |          |          |
| **Loans Receivable [Line Items]**                                                                                                                                       |          |          |
| Financing receivables                                                                                                                                                   | 192,379       | 217,607       |
| FICO score not applicable | LTV less than or equal to 70% | Residential Mortgages(1)(3)                                                                                 |          |          |
| **Loans Receivable [Line Items]**                                                                                                                                       |          |          |
| Financing receivables                                                                                                                                                   | 12,250        | 14,801        |
| FICO score not applicable | LTV less than or equal to 70% | Home Equity Loans and Lines of Credit(2)                                                                    |          |          |
| **Loans Receivable [Line Items]**                                                                                                                                       |          |          |
| Financing receivables                                                                                                                                                   | 390           | 2,265         |
| FICO score not applicable | LTV of 70.01% to 80% | Residential Mortgages(1)(3)                                                                                          |          |          |
| **Loans Receivable [Line Items]**                                                                                                                                       |          |          |
| Financing receivables                                                                                                                                                   | 2,769         | 643           |
| FICO score not applicable | LTV of 70.01% to 90% | Home Equity Loans and Lines of Credit(2)                                                                             |          |          |
| **Loans Receivable [Line Items]**                                                                                                                                       |          |          |
| Financing receivables                                                                                                                                                   | 305           | 863           |
| FICO score not applicable | LTV of 80.01% to 90% | Residential Mortgages(1)(3)                                                                                          |          |          |
| **Loans Receivable [Line Items]**                                                                                                                                       |          |          |
| Financing receivables                                                                                                                                                   | 0             | 8,676         |
| FICO score not applicable | LTV of 90.01% to 100% | Residential Mortgages(1)(3)                                                                                         |          |          |
| **Loans Receivable [Line Items]**                                                                                                                                       |          |          |
| Financing receivables                                                                                                                                                   | 0             | 14,934        |
| FICO score not applicable | LTV of 90.01% to 110% | Home Equity Loans and Lines of Credit(2)                                                                            |          |          |
| **Loans Receivable [Line Items]**                                                                                                                                       |          |          |
| Financing receivables                                                                                                                                                   | 0             | 336           |
| FICO score not applicable | LTV of 100.01% to 110% | Residential Mortgages(1)(3)                                                                                        |          |          |
| **Loans Receivable [Line Items]**                                                                                                                                       |          |          |
| Financing receivables                                                                                                                                                   | 0             | 0             |
| FICO score not applicable | LTV greater than 110% | Residential Mortgages(1)(3)                                                                                         |          |          |
| **Loans Receivable [Line Items]**                                                                                                                                       |          |          |
| Financing receivables                                                                                                                                                   | 0             | 0             |
| FICO score not applicable | LTV greater than 110% | Home Equity Loans and Lines of Credit(2)                                                                            |          |          |
| **Loans Receivable [Line Items]**                                                                                                                                       |          |          |
| Financing receivables                                                                                                                                                   | 0             | 148           |
| FICO Score Less than 600 | Residential Mortgages(1)(3)                                                                                                                  |          |          |
| **Loans Receivable [Line Items]**                                                                                                                                       |          |          |
| Financing receivables                                                                                                                                                   | 362,824       | 460,284       |
| FICO Score Less than 600 | Home Equity Loans and Lines of Credit(2)                                                                                                     |          |          |
| **Loans Receivable [Line Items]**                                                                                                                                       |          |          |
| Financing receivables                                                                                                                                                   | 290,439       | 286,694       |
| FICO Score Less than 600 | LTV not applicable | Residential Mortgages(1)(3)                                                                                             |          |          |
| **Loans Receivable [Line Items]**                                                                                                                                       |          |          |
| Financing receivables                                                                                                                                                   | 128           | 94            |
| FICO Score Less than 600 | LTV not applicable | Home Equity Loans and Lines of Credit(2)                                                                                |          |          |
| **Loans Receivable [Line Items]**                                                                                                                                       |          |          |
| Financing receivables                                                                                                                                                   | 11,110        | 13,543        |
| FICO Score Less than 600 | LTV less than or equal to 70% | Residential Mortgages(1)(3)                                                                                  |          |          |
| **Loans Receivable [Line Items]**                                                                                                                                       |          |          |
| Financing receivables                                                                                                                                                   | 226,185       | 279,197       |
| FICO Score Less than 600 | LTV less than or equal to 70% | Home Equity Loans and Lines of Credit(2)                                                                     |          |          |
| **Loans Receivable [Line Items]**                                                                                                                                       |          |          |
| Financing receivables                                                                                                                                                   | 155,306       | 158,712       |
| FICO Score Less than 600 | LTV of 70.01% to 80% | Residential Mortgages(1)(3)                                                                                           |          |          |
| **Loans Receivable [Line Items]**                                                                                                                                       |          |          |
| Financing receivables                                                                                                                                                   | 69,698        | 91,037        |
| FICO Score Less than 600 | LTV of 70.01% to 90% | Home Equity Loans and Lines of Credit(2)                                                                              |          |          |
| **Loans Receivable [Line Items]**                                                                                                                                       |          |          |
| Financing receivables                                                                                                                                                   | 79,389        | 69,381        |
| FICO Score Less than 600 | LTV of 80.01% to 90% | Residential Mortgages(1)(3)                                                                                           |          |          |
| **Loans Receivable [Line Items]**                                                                                                                                       |          |          |
| Financing receivables                                                                                                                                                   | 30,491        | 41,341        |
| FICO Score Less than 600 | LTV of 90.01% to 100% | Residential Mortgages(1)(3)                                                                                          |          |          |
| **Loans Receivable [Line Items]**                                                                                                                                       |          |          |
| Financing receivables                                                                                                                                                   | 18,279        | 17,271        |
| FICO Score Less than 600 | LTV of 90.01% to 110% | Home Equity Loans and Lines of Credit(2)                                                                             |          |          |
| **Loans Receivable [Line Items]**                                                                                                                                       |          |          |
| Financing receivables                                                                                                                                                   | 22,373        | 24,069        |
| FICO Score Less than 600 | LTV of 100.01% to 110% | Residential Mortgages(1)(3)                                                                                         |          |          |
| **Loans Receivable [Line Items]**                                                                                                                                       |          |          |
| Financing receivables                                                                                                                                                   | 8,441         | 15,017        |
| FICO Score Less than 600 | LTV greater than 110% | Residential Mortgages(1)(3)                                                                                          |          |          |
| **Loans Receivable [Line Items]**                                                                                                                                       |          |          |
| Financing receivables                                                                                                                                                   | 9,602         | 16,327        |
| FICO Score Less than 600 | LTV greater than 110% | Home Equity Loans and Lines of Credit(2)                                                                             |          |          |
| **Loans Receivable [Line Items]**                                                                                                                                       |          |          |
| Financing receivables                                                                                                                                                   | 22,261        | 20,989        |
| FICO Score of 600 to 639 | Residential Mortgages(1)(3)                                                                                                                  |          |          |
| **Loans Receivable [Line Items]**                                                                                                                                       |          |          |
| Financing receivables                                                                                                                                                   | 252,976       | 263,857       |
| FICO Score of 600 to 639 | Home Equity Loans and Lines of Credit(2)                                                                                                     |          |          |
| **Loans Receivable [Line Items]**                                                                                                                                       |          |          |
| Financing receivables                                                                                                                                                   | 265,987       | 278,594       |
| FICO Score of 600 to 639 | LTV not applicable | Residential Mortgages(1)(3)                                                                                             |          |          |
| **Loans Receivable [Line Items]**                                                                                                                                       |          |          |
| Financing receivables                                                                                                                                                   | 1             | 200           |
| FICO Score of 600 to 639 | LTV not applicable | Home Equity Loans and Lines of Credit(2)                                                                                |          |          |
| **Loans Receivable [Line Items]**                                                                                                                                       |          |          |
| Financing receivables                                                                                                                                                   | 8,871         | 9,748         |
| FICO Score of 600 to 639 | LTV less than or equal to 70% | Residential Mortgages(1)(3)                                                                                  |          |          |
| **Loans Receivable [Line Items]**                                                                                                                                       |          |          |
| Financing receivables                                                                                                                                                   | 158,290       | 154,557       |
| FICO Score of 600 to 639 | LTV less than or equal to 70% | Home Equity Loans and Lines of Credit(2)                                                                     |          |          |
| **Loans Receivable [Line Items]**                                                                                                                                       |          |          |
| Financing receivables                                                                                                                                                   | 140,277       | 154,887       |
| FICO Score of 600 to 639 | LTV of 70.01% to 80% | Residential Mortgages(1)(3)                                                                                           |          |          |
| **Loans Receivable [Line Items]**                                                                                                                                       |          |          |
| Financing receivables                                                                                                                                                   | 43,002        | 50,238        |
| FICO Score of 600 to 639 | LTV of 70.01% to 90% | Home Equity Loans and Lines of Credit(2)                                                                              |          |          |
| **Loans Receivable [Line Items]**                                                                                                                                       |          |          |
| Financing receivables                                                                                                                                                   | 83,548        | 76,431        |
| FICO Score of 600 to 639 | LTV of 80.01% to 90% | Residential Mortgages(1)(3)                                                                                           |          |          |
| **Loans Receivable [Line Items]**                                                                                                                                       |          |          |
| Financing receivables                                                                                                                                                   | 23,281        | 25,861        |
| FICO Score of 600 to 639 | LTV of 90.01% to 100% | Residential Mortgages(1)(3)                                                                                          |          |          |
| **Loans Receivable [Line Items]**                                                                                                                                       |          |          |
| Financing receivables                                                                                                                                                   | 15,585        | 13,218        |
| FICO Score of 600 to 639 | LTV of 90.01% to 110% | Home Equity Loans and Lines of Credit(2)                                                                             |          |          |
| **Loans Receivable [Line Items]**                                                                                                                                       |          |          |
| Financing receivables                                                                                                                                                   | 20,766        | 23,410        |
| FICO Score of 600 to 639 | LTV of 100.01% to 110% | Residential Mortgages(1)(3)                                                                                         |          |          |
| **Loans Receivable [Line Items]**                                                                                                                                       |          |          |
| Financing receivables                                                                                                                                                   | 5,238         | 6,337         |
| FICO Score of 600 to 639 | LTV greater than 110% | Residential Mortgages(1)(3)                                                                                          |          |          |
| **Loans Receivable [Line Items]**                                                                                                                                       |          |          |
| Financing receivables                                                                                                                                                   | 7,579         | 13,446        |
| FICO Score of 600 to 639 | LTV greater than 110% | Home Equity Loans and Lines of Credit(2)                                                                             |          |          |
| **Loans Receivable [Line Items]**                                                                                                                                       |          |          |
| Financing receivables                                                                                                                                                   | 12,525        | 14,118        |
| FICO Score of 640 to 679 | Residential Mortgages(1)(3)                                                                                                                  |          |          |
| **Loans Receivable [Line Items]**                                                                                                                                       |          |          |
| Financing receivables                                                                                                                                                   | 419,770       | 488,841       |
| FICO Score of 640 to 679 | Home Equity Loans and Lines of Credit(2)                                                                                                     |          |          |
| **Loans Receivable [Line Items]**                                                                                                                                       |          |          |
| Financing receivables                                                                                                                                                   | 500,728       | 514,502       |
| FICO Score of 640 to 679 | LTV not applicable | Residential Mortgages(1)(3)                                                                                             |          |          |
| **Loans Receivable [Line Items]**                                                                                                                                       |          |          |
| Financing receivables                                                                                                                                                   | 230           | 0             |
| FICO Score of 640 to 679 | LTV not applicable | Home Equity Loans and Lines of Credit(2)                                                                                |          |          |
| **Loans Receivable [Line Items]**                                                                                                                                       |          |          |
| Financing receivables                                                                                                                                                   | 12,534        | 14,717        |
| FICO Score of 640 to 679 | LTV less than or equal to 70% | Residential Mortgages(1)(3)                                                                                  |          |          |
| **Loans Receivable [Line Items]**                                                                                                                                       |          |          |
| Financing receivables                                                                                                                                                   | 252,727       | 303,319       |
| FICO Score of 640 to 679 | LTV less than or equal to 70% | Home Equity Loans and Lines of Credit(2)                                                                     |          |          |
| **Loans Receivable [Line Items]**                                                                                                                                       |          |          |
| Financing receivables                                                                                                                                                   | 254,481       | 279,397       |
| FICO Score of 640 to 679 | LTV of 70.01% to 80% | Residential Mortgages(1)(3)                                                                                           |          |          |
| **Loans Receivable [Line Items]**                                                                                                                                       |          |          |
| Financing receivables                                                                                                                                                   | 81,552        | 87,055        |
| FICO Score of 640 to 679 | LTV of 70.01% to 90% | Home Equity Loans and Lines of Credit(2)                                                                              |          |          |
| **Loans Receivable [Line Items]**                                                                                                                                       |          |          |
| Financing receivables                                                                                                                                                   | 174,223       | 157,214       |
| FICO Score of 640 to 679 | LTV of 80.01% to 90% | Residential Mortgages(1)(3)                                                                                           |          |          |
| **Loans Receivable [Line Items]**                                                                                                                                       |          |          |
| Financing receivables                                                                                                                                                   | 35,001        | 40,863        |
| FICO Score of 640 to 679 | LTV of 90.01% to 100% | Residential Mortgages(1)(3)                                                                                          |          |          |
| **Loans Receivable [Line Items]**                                                                                                                                       |          |          |
| Financing receivables                                                                                                                                                   | 29,125        | 26,618        |
| FICO Score of 640 to 679 | LTV of 90.01% to 110% | Home Equity Loans and Lines of Credit(2)                                                                             |          |          |
| **Loans Receivable [Line Items]**                                                                                                                                       |          |          |
| Financing receivables                                                                                                                                                   | 32,925        | 38,057        |
| FICO Score of 640 to 679 | LTV of 100.01% to 110% | Residential Mortgages(1)(3)                                                                                         |          |          |
| **Loans Receivable [Line Items]**                                                                                                                                       |          |          |
| Financing receivables                                                                                                                                                   | 9,101         | 11,456        |
| FICO Score of 640 to 679 | LTV greater than 110% | Residential Mortgages(1)(3)                                                                                          |          |          |
| **Loans Receivable [Line Items]**                                                                                                                                       |          |          |
| Financing receivables                                                                                                                                                   | 12,034        | 19,530        |
| FICO Score of 640 to 679 | LTV greater than 110% | Home Equity Loans and Lines of Credit(2)                                                                             |          |          |
| **Loans Receivable [Line Items]**                                                                                                                                       |          |          |
| Financing receivables                                                                                                                                                   | 26,565        | 25,117        |
| FICO Score of 680 to 719 | Residential Mortgages(1)(3)                                                                                                                  |          |          |
| **Loans Receivable [Line Items]**                                                                                                                                       |          |          |
| Financing receivables                                                                                                                                                   | 792,060       | 843,357       |
| FICO Score of 680 to 719 | Home Equity Loans and Lines of Credit(2)                                                                                                     |          |          |
| **Loans Receivable [Line Items]**                                                                                                                                       |          |          |
| Financing receivables                                                                                                                                                   | 851,662       | 867,323       |
| FICO Score of 680 to 719 | LTV not applicable | Residential Mortgages(1)(3)                                                                                             |          |          |
| **Loans Receivable [Line Items]**                                                                                                                                       |          |          |
| Financing receivables                                                                                                                                                   | 19            | 25            |
| FICO Score of 680 to 719 | LTV not applicable | Home Equity Loans and Lines of Credit(2)                                                                                |          |          |
| **Loans Receivable [Line Items]**                                                                                                                                       |          |          |
| Financing receivables                                                                                                                                                   | 14,273        | 15,984        |
| FICO Score of 680 to 719 | LTV less than or equal to 70% | Residential Mortgages(1)(3)                                                                                  |          |          |
| **Loans Receivable [Line Items]**                                                                                                                                       |          |          |
| Financing receivables                                                                                                                                                   | 462,180       | 528,979       |
| FICO Score of 680 to 719 | LTV less than or equal to 70% | Home Equity Loans and Lines of Credit(2)                                                                     |          |          |
| **Loans Receivable [Line Items]**                                                                                                                                       |          |          |
| Financing receivables                                                                                                                                                   | 431,818       | 488,982       |
| FICO Score of 680 to 719 | LTV of 70.01% to 80% | Residential Mortgages(1)(3)                                                                                           |          |          |
| **Loans Receivable [Line Items]**                                                                                                                                       |          |          |
| Financing receivables                                                                                                                                                   | 183,568       | 161,023       |
| FICO Score of 680 to 719 | LTV of 70.01% to 90% | Home Equity Loans and Lines of Credit(2)                                                                              |          |          |
| **Loans Receivable [Line Items]**                                                                                                                                       |          |          |
| Financing receivables                                                                                                                                                   | 317,260       | 272,083       |
| FICO Score of 680 to 719 | LTV of 80.01% to 90% | Residential Mortgages(1)(3)                                                                                           |          |          |
| **Loans Receivable [Line Items]**                                                                                                                                       |          |          |
| Financing receivables                                                                                                                                                   | 62,670        | 66,898        |
| FICO Score of 680 to 719 | LTV of 90.01% to 100% | Residential Mortgages(1)(3)                                                                                          |          |          |
| **Loans Receivable [Line Items]**                                                                                                                                       |          |          |
| Financing receivables                                                                                                                                                   | 51,659        | 40,456        |
| FICO Score of 680 to 719 | LTV of 90.01% to 110% | Home Equity Loans and Lines of Credit(2)                                                                             |          |          |
| **Loans Receivable [Line Items]**                                                                                                                                       |          |          |
| Financing receivables                                                                                                                                                   | 56,589        | 56,560        |
| FICO Score of 680 to 719 | LTV of 100.01% to 110% | Residential Mortgages(1)(3)                                                                                         |          |          |
| **Loans Receivable [Line Items]**                                                                                                                                       |          |          |
| Financing receivables                                                                                                                                                   | 9,194         | 11,503        |
| FICO Score of 680 to 719 | LTV greater than 110% | Residential Mortgages(1)(3)                                                                                          |          |          |
| **Loans Receivable [Line Items]**                                                                                                                                       |          |          |
| Financing receivables                                                                                                                                                   | 22,770        | 34,473        |
| FICO Score of 680 to 719 | LTV greater than 110% | Home Equity Loans and Lines of Credit(2)                                                                             |          |          |
| **Loans Receivable [Line Items]**                                                                                                                                       |          |          |
| Financing receivables                                                                                                                                                   | 31,722        | 33,714        |
| FICO Score of 720 to 759 | Residential Mortgages(1)(3)                                                                                                                  |          |          |
| **Loans Receivable [Line Items]**                                                                                                                                       |          |          |
| Financing receivables                                                                                                                                                   | 1,183,942     | 1,209,832     |
| FICO Score of 720 to 759 | Home Equity Loans and Lines of Credit(2)                                                                                                     |          |          |
| **Loans Receivable [Line Items]**                                                                                                                                       |          |          |
| Financing receivables                                                                                                                                                   | 1,156,986     | 1,181,245     |
| FICO Score of 720 to 759 | LTV not applicable | Residential Mortgages(1)(3)                                                                                             |          |          |
| **Loans Receivable [Line Items]**                                                                                                                                       |          |          |
| Financing receivables                                                                                                                                                   | 339           | 314           |
| FICO Score of 720 to 759 | LTV not applicable | Home Equity Loans and Lines of Credit(2)                                                                                |          |          |
| **Loans Receivable [Line Items]**                                                                                                                                       |          |          |
| Financing receivables                                                                                                                                                   | 12,673        | 15,643        |
| FICO Score of 720 to 759 | LTV less than or equal to 70% | Residential Mortgages(1)(3)                                                                                  |          |          |
| **Loans Receivable [Line Items]**                                                                                                                                       |          |          |
| Financing receivables                                                                                                                                                   | 681,473       | 758,315       |
| FICO Score of 720 to 759 | LTV less than or equal to 70% | Home Equity Loans and Lines of Credit(2)                                                                     |          |          |
| **Loans Receivable [Line Items]**                                                                                                                                       |          |          |
| Financing receivables                                                                                                                                                   | 614,748       | 672,971       |
| FICO Score of 720 to 759 | LTV of 70.01% to 80% | Residential Mortgages(1)(3)                                                                                           |          |          |
| **Loans Receivable [Line Items]**                                                                                                                                       |          |          |
| Financing receivables                                                                                                                                                   | 341,934       | 271,983       |
| FICO Score of 720 to 759 | LTV of 70.01% to 90% | Home Equity Loans and Lines of Credit(2)                                                                              |          |          |
| **Loans Receivable [Line Items]**                                                                                                                                       |          |          |
| Financing receivables                                                                                                                                                   | 425,744       | 381,828       |
| FICO Score of 720 to 759 | LTV of 80.01% to 90% | Residential Mortgages(1)(3)                                                                                           |          |          |
| **Loans Receivable [Line Items]**                                                                                                                                       |          |          |
| Financing receivables                                                                                                                                                   | 72,729        | 80,077        |
| FICO Score of 720 to 759 | LTV of 90.01% to 100% | Residential Mortgages(1)(3)                                                                                          |          |          |
| **Loans Receivable [Line Items]**                                                                                                                                       |          |          |
| Financing receivables                                                                                                                                                   | 55,461        | 42,872        |
| FICO Score of 720 to 759 | LTV of 90.01% to 110% | Home Equity Loans and Lines of Credit(2)                                                                             |          |          |
| **Loans Receivable [Line Items]**                                                                                                                                       |          |          |
| Financing receivables                                                                                                                                                   | 63,840        | 64,993        |
| FICO Score of 720 to 759 | LTV of 100.01% to 110% | Residential Mortgages(1)(3)                                                                                         |          |          |
| **Loans Receivable [Line Items]**                                                                                                                                       |          |          |
| Financing receivables                                                                                                                                                   | 11,024        | 16,344        |
| FICO Score of 720 to 759 | LTV greater than 110% | Residential Mortgages(1)(3)                                                                                          |          |          |
| **Loans Receivable [Line Items]**                                                                                                                                       |          |          |
| Financing receivables                                                                                                                                                   | 20,982        | 39,927        |
| FICO Score of 720 to 759 | LTV greater than 110% | Home Equity Loans and Lines of Credit(2)                                                                             |          |          |
| **Loans Receivable [Line Items]**                                                                                                                                       |          |          |
| Financing receivables                                                                                                                                                   | 39,981        | 45,810        |
| FICO Score Equal to or Greater than 760 | Residential Mortgages(1)(3)                                                                                                   |          |          |
| **Loans Receivable [Line Items]**                                                                                                                                       |          |          |
| Financing receivables                                                                                                                                                   | 2,979,325     | 3,226,869     |
| FICO Score Equal to or Greater than 760 | Home Equity Loans and Lines of Credit(2)                                                                                      |          |          |
| **Loans Receivable [Line Items]**                                                                                                                                       |          |          |
| Financing receivables                                                                                                                                                   | 2,892,356     | 2,861,721     |
| FICO Score Equal to or Greater than 760 | LTV not applicable | Residential Mortgages(1)(3)                                                                              |          |          |
| **Loans Receivable [Line Items]**                                                                                                                                       |          |          |
| Financing receivables                                                                                                                                                   | 84            | 124           |
| FICO Score Equal to or Greater than 760 | LTV not applicable | Home Equity Loans and Lines of Credit(2)                                                                 |          |          |
| **Loans Receivable [Line Items]**                                                                                                                                       |          |          |
| Financing receivables                                                                                                                                                   | 34,579        | 36,962        |
| FICO Score Equal to or Greater than 760 | LTV less than or equal to 70% | Residential Mortgages(1)(3)                                                                   |          |          |
| **Loans Receivable [Line Items]**                                                                                                                                       |          |          |
| Financing receivables                                                                                                                                                   | 2,049,268     | 2,328,907     |
| FICO Score Equal to or Greater than 760 | LTV less than or equal to 70% | Home Equity Loans and Lines of Credit(2)                                                      |          |          |
| **Loans Receivable [Line Items]**                                                                                                                                       |          |          |
| Financing receivables                                                                                                                                                   | 1,644,168     | 1,736,574     |
| FICO Score Equal to or Greater than 760 | LTV of 70.01% to 80% | Residential Mortgages(1)(3)                                                                            |          |          |
| **Loans Receivable [Line Items]**                                                                                                                                       |          |          |
| Financing receivables                                                                                                                                                   | 717,671       | 633,004       |
| FICO Score Equal to or Greater than 760 | LTV of 70.01% to 90% | Home Equity Loans and Lines of Credit(2)                                                               |          |          |
| **Loans Receivable [Line Items]**                                                                                                                                       |          |          |
| Financing receivables                                                                                                                                                   | 1,007,561     | 885,774       |
| FICO Score Equal to or Greater than 760 | LTV of 80.01% to 90% | Residential Mortgages(1)(3)                                                                            |          |          |
| **Loans Receivable [Line Items]**                                                                                                                                       |          |          |
| Financing receivables                                                                                                                                                   | 112,721       | 132,640       |
| FICO Score Equal to or Greater than 760 | LTV of 90.01% to 100% | Residential Mortgages(1)(3)                                                                           |          |          |
| **Loans Receivable [Line Items]**                                                                                                                                       |          |          |
| Financing receivables                                                                                                                                                   | 57,385        | 60,434        |
| FICO Score Equal to or Greater than 760 | LTV of 90.01% to 110% | Home Equity Loans and Lines of Credit(2)                                                              |          |          |
| **Loans Receivable [Line Items]**                                                                                                                                       |          |          |
| Financing receivables                                                                                                                                                   | 135,571       | 125,773       |
| FICO Score Equal to or Greater than 760 | LTV of 100.01% to 110% | Residential Mortgages(1)(3)                                                                          |          |          |
| **Loans Receivable [Line Items]**                                                                                                                                       |          |          |
| Financing receivables                                                                                                                                                   | 21,580        | 29,738        |
| FICO Score Equal to or Greater than 760 | LTV greater than 110% | Residential Mortgages(1)(3)                                                                           |          |          |
| **Loans Receivable [Line Items]**                                                                                                                                       |          |          |
| Financing receivables                                                                                                                                                   | 20,616        | 42,022        |
| FICO Score Equal to or Greater than 760 | LTV greater than 110% | Home Equity Loans and Lines of Credit(2)                                                              |          |          |
| **Loans Receivable [Line Items]**                                                                                                                                       |          |          |
| Financing receivables                                                                                                                                                   | $ 70,477      | $ 76,638      |

| X                                                                                                                                                                                                                                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The balance of financing receivables including loans held-for-sale, before allowance for credit losses.
+ References
No definition available.
+ Details**Name:**sov_FinancingReceivableIncludingReceivableHeldForSaleGross**Namespace Prefix:**sov_**Data Type:**xbrli:monetaryItemType**Balance Type:**debit**Period Type:**instant |
| X                                                                                                                                                                                                                                                                                                                                                                                                                                |
|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.
+ References
No definition available.
+ Details**Name:**us-gaap_AccountsNotesAndLoansReceivableLineItems**Namespace Prefix:**us-gaap_**Data Type:**xbrli:stringItemType**Balance Type:**na**Period Type:**duration |
| X                                                                                                                                                                              |
|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Details**Name:**us-gaap_FinancingReceivablePortfolioSegmentAxis=us-gaap_ConsumerPortfolioSegmentMember**Namespace Prefix:****Data Type:**na**Balance Type:****Period Type:** |
| X                                                                                                                                                                                                       |
|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Details**Name:**us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=us-gaap_ResidentialMortgageMember**Namespace Prefix:****Data Type:**na**Balance Type:****Period Type:** |
| X                                                                                                                                                                                                               |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Details**Name:**us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=sov_HomeEquityLoansandLinesofCreditMember**Namespace Prefix:****Data Type:**na**Balance Type:****Period Type:** |
| X                                                                                                                                          |
|--------------------------------------------------------------------------------------------------------------------------------------------|
| - Details**Name:**us-gaap_LoanToValueAxis=sov_LtvNotApplicableMember**Namespace Prefix:****Data Type:**na**Balance Type:****Period Type:** |
| X                                                                                                                                                |
|--------------------------------------------------------------------------------------------------------------------------------------------------|
| - Details**Name:**us-gaap_LoanToValueAxis=sov_LTVlessthanorequalto70Member**Namespace Prefix:****Data Type:**na**Balance Type:****Period Type:** |
| X                                                                                                                                        |
|------------------------------------------------------------------------------------------------------------------------------------------|
| - Details**Name:**us-gaap_LoanToValueAxis=sov_LTVof70.01to80Member**Namespace Prefix:****Data Type:**na**Balance Type:****Period Type:** |
| X                                                                                                                                        |
|------------------------------------------------------------------------------------------------------------------------------------------|
| - Details**Name:**us-gaap_LoanToValueAxis=sov_LTVof70.01to90Member**Namespace Prefix:****Data Type:**na**Balance Type:****Period Type:** |
| X                                                                                                                                       |
|-----------------------------------------------------------------------------------------------------------------------------------------|
| - Details**Name:**us-gaap_LoanToValueAxis=sov_LtvOf8001To90Member**Namespace Prefix:****Data Type:**na**Balance Type:****Period Type:** |
| X                                                                                                                                        |
|------------------------------------------------------------------------------------------------------------------------------------------|
| - Details**Name:**us-gaap_LoanToValueAxis=sov_LtvOf9001To100Member**Namespace Prefix:****Data Type:**na**Balance Type:****Period Type:** |
| X                                                                                                                                         |
|-------------------------------------------------------------------------------------------------------------------------------------------|
| - Details**Name:**us-gaap_LoanToValueAxis=sov_LTVof90.01to110Member**Namespace Prefix:****Data Type:**na**Balance Type:****Period Type:** |
| X                                                                                                                                          |
|--------------------------------------------------------------------------------------------------------------------------------------------|
| - Details**Name:**us-gaap_LoanToValueAxis=sov_LTVof100.01to110Member**Namespace Prefix:****Data Type:**na**Balance Type:****Period Type:** |
| X                                                                                                                                           |
|---------------------------------------------------------------------------------------------------------------------------------------------|
| - Details**Name:**us-gaap_LoanToValueAxis=sov_LTVgreaterthan110Member**Namespace Prefix:****Data Type:**na**Balance Type:****Period Type:** |
| X                                                                                                                                                   |
|-----------------------------------------------------------------------------------------------------------------------------------------------------|
| - Details**Name:**us-gaap_CreditScoreFicoAxis=sov_FicoScoreNotRefreshedMember**Namespace Prefix:****Data Type:**na**Balance Type:****Period Type:** |
| X                                                                                                                                                  |
|----------------------------------------------------------------------------------------------------------------------------------------------------|
| - Details**Name:**us-gaap_CreditScoreFicoAxis=sov_FICOScoreLessthan600Member**Namespace Prefix:****Data Type:**na**Balance Type:****Period Type:** |
| X                                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------------------------|
| - Details**Name:**us-gaap_CreditScoreFicoAxis=sov_FICOScoreof600to639Member**Namespace Prefix:****Data Type:**na**Balance Type:****Period Type:** |
| X                                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------------------------|
| - Details**Name:**us-gaap_CreditScoreFicoAxis=sov_FICOScoreof640to679Member**Namespace Prefix:****Data Type:**na**Balance Type:****Period Type:** |
| X                                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------------------------|
| - Details**Name:**us-gaap_CreditScoreFicoAxis=sov_FICOScoreof680to719Member**Namespace Prefix:****Data Type:**na**Balance Type:****Period Type:** |
| X                                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------------------------|
| - Details**Name:**us-gaap_CreditScoreFicoAxis=sov_FICOScoreof720to759Member**Namespace Prefix:****Data Type:**na**Balance Type:****Period Type:** |
| X                                                                                                                                                              |
|----------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Details**Name:**us-gaap_CreditScoreFicoAxis=sov_FICOScoreEqualtoorGreaterthan760Member**Namespace Prefix:****Data Type:**na**Balance Type:****Period Type:** |