FAIR VALUE (Details 7) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011
Financial Assets
Federal funds sold	$ 30,000
Estimated Fair Value
Financial Assets
Cash and cash equivalents	2,429,614	1,431,185
Short-term investments	254,714	61,834
Federal funds sold	30,000
Securities purchased under resale agreements	670,342	791,745
Loans Held for sale	142,211	285,181
Loans receivable, net	13,435,594	13,520,712
Investment in Federal Home Loan Bank stock	124,223	136,897
Investment in Federal Reserve Bank stock	47,748	47,512
Accrued interest receivable	85,389	89,686
Financial Liabilities
Demand, savings and money market deposits	11,040,151	10,307,001
Time deposits	6,326,965	7,194,125
Federal Home Loan Bank advances	383,493	479,029
Securities sold under repurchase agreements	1,184,501	1,177,331
Accrued interest payable	9,846	15,447
Long-term debt	145,644	144,392
Level 1
Financial Assets
Cash and cash equivalents	2,429,614	1,431,185
Level 2
Financial Assets
Short-term investments	254,714	61,834
Federal funds sold	30,000
Securities purchased under resale agreements	670,342	791,745
Loans Held for sale	142,211	285,181
Investment in Federal Home Loan Bank stock	124,223	136,897
Investment in Federal Reserve Bank stock	47,748	47,512
Accrued interest receivable	85,389	89,686
Financial Liabilities
Demand, savings and money market deposits	11,040,151	10,307,001
Federal Home Loan Bank advances	383,493	479,029
Securities sold under repurchase agreements	1,184,501	1,177,331
Accrued interest payable	9,846	15,447
Long-term debt	145,644	144,392
Level 3
Financial Assets
Loans receivable, net	13,435,594	13,520,712
Financial Liabilities
Time deposits	$ 6,326,965	$ 7,194,125