FAIR VALUE (Details 6) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2012 Carrying Amount or Notional Amount	Dec. 31, 2011 Carrying Amount or Notional Amount	Mar. 31, 2012 Estimated Fair Value	Dec. 31, 2011 Estimated Fair Value
Financial Assets
Cash and cash equivalents		$ 1,635,854	$ 1,431,185	$ 1,635,854	$ 1,431,185
Short-term investments		177,576	61,834	177,576	61,834
Federal funds sold	30,000	30,000		30,000
Securities purchased under resale agreements		650,000	786,434	646,041	791,745
Investment securities available-for-sale		2,706,720	3,072,578	2,706,720	3,072,578
Loans Held for sale		280,830	278,603	289,989	285,181
Loans receivable, net		13,948,524	13,984,930	13,310,866	13,520,712
Investment in Federal Home Loan Bank stock		130,506	136,897	130,506	136,897
Investment in Federal Reserve Bank stock		47,639	47,512	47,639	47,512
Accrued interest receivable		95,337	89,686	95,337	89,686
Equity swap agreements		22,709	22,709	204	202
Foreign exchange options		85,614	85,614	4,695	3,899
Interest rate swaps		533,735	585,196	18,432	20,474
Short-term foreign exchange contracts		200,898	210,295	2,045	1,403
Financial Liabilities
Demand, savings and money market deposits		10,563,249	10,307,001	10,563,249	10,307,001
Time deposits		6,775,320	7,146,001	6,821,016	7,194,125
Federal Home Loan Bank advances		394,719	455,251	420,758	479,029
Securities sold under repurchase agreements		995,000	1,020,208	1,172,723	1,177,331
Accrued interest payable		16,439	15,447	16,439	15,447
Long-term debt		212,178	212,178	139,361	144,392
Derivatives liabilities		$ 1,041,860	$ 835,913	$ 25,291	$ 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