| **GOODWILL AND OTHER INTANGIBLES (As Restated) (Tables)**               | 12 Months Ended                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |
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| **Goodwill and Intangible Assets Disclosure [Abstract]**                |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        |
| Schedule of Goodwill                                                    | The following table presents activity in the Company's goodwill by its reportable segments for the year endedDecember 31, 2015:  Retail Banking Auto Finance & Business Banking(2) Real Estate and Commercial Banking Global Corporate Banking(1) SC Total  (in thousands)Goodwill at December 31, 2014 $1,815,729 $71,522 $1,406,048 $131,130 $5,527,055 $8,951,484Disposals during the period — — — — — —Additions during the period — — — — — —Impairment during the period — — — — (4,507,095) (4,507,095)Re-allocations during the period (265,408) 374,401 (108,993) — — —Goodwill at December 31, 2015 $1,550,321 $445,923 $1,297,055 $131,130 $1,019,960 $4,444,389 (1)  The Global Corporate Banking ("GCB") was formerly designated as the Global Corporate Banking & Market & Large Corporate Banking ("GBM") segment and was renamed during the third quarter of 2015.(2)  The Auto Finance & Business Banking was formerly designated as the Auto Finance and Alliances segment and was renamed during the third quarter of 2015. |
| Schedule of Finite-Lived and Indefinite-Lived Intangible Assets         | The following table details amounts related to the Company's finite-lived and indefinite-lived intangible assets for the dates indicated.  December 31, 2015 December 31, 2014 NetCarryingAmount AccumulatedAmortization NetCarryingAmount AccumulatedAmortization (in thousands)Intangibles subject to amortization:       Dealer networks$504,839 $(75,161) $544,054 $(35,946)Chrysler relationship110,000 (28,750) 125,000 (13,750)Core deposit intangibles763 (295,079) 7,779 (288,063)Other intangibles5,453 (24,455) 8,655 (21,253)Total intangibles subject to amortization621,055 (423,445) 685,488 (359,012)Intangibles not subject to amortization:       Trade name18,000 — 21,500 —Total Intangibles$639,055 $(423,445) $706,988 $(359,012)                                                                                                                                                                                                                                                                                                                                                                                                                             |
| Schedule of Finite-Lived Intangible Assets, Future Amortization Expense | The estimated aggregate amortization expense related to intangibles for each of the five succeeding calendar years ending December 31 is:Year Calendar Year Amount  (in thousands)2016 $57,1622017 55,0552018 54,7022019 54,5012020 54,441Thereafter 345,194                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |

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| - Definition
Schedule of Finite-Lived and Indefinite-Lived Intangible Assets [Table Text Block]
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| - Definition
Tabular disclosure of goodwill by reportable segment and in total which includes a rollforward schedule.
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Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 20 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=35741047&loc=d3e13816-109267Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 20 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=35741047&loc=d3e13854-109267
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Tabular disclosure of the amount of amortization expense expected to be recorded in succeeding fiscal years for finite-lived intangible assets.
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Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 30 -Section 50 -Paragraph 2 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=26713463&loc=d3e16323-109275
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