| **DEPOSITS AND OTHER CUSTOMER ACCOUNTS** | 3 Months Ended                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |
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| **Deposits [Abstract]**                  |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
| DEPOSITS AND OTHER CUSTOMER ACCOUNTS     | DEPOSITS AND OTHER CUSTOMER ACCOUNTSDeposits and other customer accounts are summarized as follows: March 31, 2016 December 31, 2015 Balance Percent of total deposits Balance Percent of total deposits (in thousands)Interest-bearing demand deposits$9,804,755 17.1% $10,253,948 18.3%Non-interest-bearing demand deposits8,565,569 14.9% 8,240,023 14.7%Savings4,149,767 7.2% 3,956,165 7.0%Customer repurchase accounts879,411 1.5% 896,736 1.6%Money market24,589,904 42.8% 24,254,357 43.2%Certificates of deposit9,474,844 16.5% 8,513,003 15.2%Total Deposits (1)$57,464,250 100% $56,114,232 100% (1)  Includes foreign deposits of $474.3 million and $495.9 million at March 31, 2016 and December 31, 2015, respectively.Deposits collateralized by investment securities, loans, and other financial instruments totaled $4.3 billion and $2.9 billion at March 31, 2016 and December 31, 2015, respectively.Demand deposit overdrafts that have been reclassified as loan balances were $37.5 million and $25.2 million at March 31, 2016 and December 31, 2015, respectively.           |

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| - Definition
The entire disclosure for deposit liabilities including data and tables. It may include a description of the entity's deposit liabilities, the aggregate amount of time deposits (including certificates of deposit) in denominations of $100,000 or more at the balance sheet date; the aggregate amount of any demand deposits that have been reclassified as loan balances, such as overdrafts, at the balance sheet date; deposits that are received on terms other than those in the normal course of business, the amount of accrued interest on deposit liabilities; securities, mortgage loans or other financial instruments that serve as collateral for deposits; for time deposits having a remaining term of more than one year, the aggregate amount of maturities for each of the five years following the balance sheet date; and the weighted average interest rate for all deposit liabilities held by the entity.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 405 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=50488274&loc=d3e64164-112818Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03.12) -URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878
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| - References
No definition available.
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