FAIR VALUE (Details 6) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Dec. 31, 2013
Financial Assets:
Investment securities available-for-sale	$ 2,474,744	$ 2,733,797
Financial Liabilities:
Maximum term of maturity for securities purchased under resale agreements to be included in cash and cash equivalents	90 days
Term of maturity that securities purchased under resale agreements must exceed to be included in certain fair value calculations	90 days
Maximum term of maturity for carrying amount of securities sold under repurchase agreements to approximate fair value	90 days
Carrying Amount
Financial Assets:
Cash and cash equivalents	1,884,855	895,820
Short-term investments	323,266	257,473
Securities purchased under resale agreements	1,200,000	1,300,000
Investment securities available-for-sale	2,474,744	2,733,797
Loans held for sale	577,353	204,970
Loans receivable, net	19,082,250	17,600,613
Investment in Federal Home Loan Bank stock	52,110	62,330
Investment in Federal Reserve Bank stock	50,370	48,333
Accrued interest receivable	102,802	116,314
Foreign exchange options	5,915	6,290
Interest rate swaps	26,293	28,078
Foreign exchange contracts	4,378	6,181
Financial Liabilities:
Demand, savings and money market deposits	16,444,764	14,588,570
Time deposits	6,383,293	5,824,348
Federal Home Loan Bank advances	315,620	315,092
Securities sold under repurchase agreements	1,005,316	995,000
Accrued interest payable	11,582	11,178
Long-term debt	240,675	226,868
Derivatives liabilities	46,778	50,262
Estimated Fair Value
Financial Assets:
Cash and cash equivalents	1,884,855	895,820
Short-term investments	323,266	257,473
Securities purchased under resale agreements	1,186,314	1,279,406
Investment securities available-for-sale	2,474,744	2,733,797
Loans held for sale	592,769	212,469
Loans receivable, net	18,494,494	16,741,674
Investment in Federal Home Loan Bank stock	52,110	62,330
Investment in Federal Reserve Bank stock	50,370	48,333
Accrued interest receivable	102,802	116,314
Foreign exchange options	5,915	6,290
Interest rate swaps	26,293	28,078
Foreign exchange contracts	4,378	6,181
Financial Liabilities:
Demand, savings and money market deposits	16,444,764	14,588,570
Time deposits	6,355,318	5,791,659
Federal Home Loan Bank advances	333,835	308,521
Securities sold under repurchase agreements	1,134,817	1,134,774
Accrued interest payable	11,582	11,178
Long-term debt	205,012	184,415
Derivatives liabilities	$ 46,778	$ 50,262