FAIR VALUE (Details 6) (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2012	Jun. 30, 2012 Carrying Amount or Notional Amount	Dec. 31, 2011 Carrying Amount or Notional Amount	Jun. 30, 2012 Estimated Fair Value	Dec. 31, 2011 Estimated Fair Value
Financial Assets
Cash and cash equivalents		$ 2,429,614	$ 1,431,185	$ 2,429,614	$ 1,431,185
Short-term investments		254,714	61,834	254,714	61,834
Federal funds sold	30,000	30,000		30,000
Securities purchased under resale agreements		675,000	786,434	670,342	791,745
Investment securities available-for-sale		1,873,739	3,072,578	1,873,739	3,072,578
Loans Held for sale		137,812	278,603	142,211	285,181
Loans receivable, net		13,972,267	13,984,930	13,435,594	13,520,712
Investment in Federal Home Loan Bank stock		124,223	136,897	124,223	136,897
Investment in Federal Reserve Bank stock		47,748	47,512	47,748	47,512
Accrued interest receivable		85,389	89,686	85,389	89,686
Equity swap agreements		22,709	22,709	204	202
Foreign exchange options		85,614	85,614	4,264	3,899
Interest rate swaps		840,956	585,196	28,582	20,474
Short-term foreign exchange contracts		92,116	210,295	877	1,403
Financial Liabilities
Demand, savings and money market deposits		11,040,151	10,307,001	11,040,151	10,307,001
Time deposits		6,301,721	7,146,001	6,326,965	7,194,125
Federal Home Loan Bank advances		362,885	455,251	383,493	479,029
Securities sold under repurchase agreements		995,000	1,020,208	1,184,501	1,177,331
Accrued interest payable		9,846	15,447	9,846	15,447
Long-term debt		212,178	212,178	145,644	144,392
Derivatives liabilities		$ 875,705	$ 835,913	$ 31,740	$ 24,164
Maximum term of maturity for securities purchased under resale agreements to be included in cash and cash equivalents (in days)	90 days
Term of maturity that securities purchased under resale agreements must exceed to be included in certain fair value calculations (in days)	90 days
Maximum term of maturity for carrying amount of securities sold under repurchase agreements to approximate fair value (in days)	90 days