FAIR VALUE (Details 7) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
Financial Liabilities:
Other borrowings		$ 20,000
Estimated Fair Value
Financial Assets:
Cash and cash equivalents	1,050,214	1,323,106
Short-term investments	330,438	366,378
Securities purchased under resale agreements	1,429,937	1,442,302
Loans held for sale	252,894	180,349
Loans receivable, net	15,255,089	14,743,218
Investment in Federal Home Loan Bank stock	86,139	107,275
Investment in Federal Reserve Bank stock	48,111	48,003
Accrued interest receivable	109,822	94,837
Financial Liabilities:
Demand, savings and money market deposits	13,329,875	12,187,740
Time deposits	5,941,410	6,115,530
Federal Home Loan Bank advances	306,521	333,060
Securities sold under repurchase agreements	1,163,468	1,173,830
Other borrowings		20,000
Accrued interest payable	9,360	10,855
Long-term debt	83,527	83,762
Level 1
Financial Assets:
Cash and cash equivalents	1,050,214	1,323,106
Level 2
Financial Assets:
Short-term investments	330,438	366,378
Securities purchased under resale agreements	1,429,937	1,442,302
Loans held for sale	252,894	180,349
Investment in Federal Home Loan Bank stock	86,139	107,275
Investment in Federal Reserve Bank stock	48,111	48,003
Accrued interest receivable	109,822	94,837
Financial Liabilities:
Demand, savings and money market deposits	13,329,875	12,187,740
Federal Home Loan Bank advances	306,521	333,060
Securities sold under repurchase agreements	1,163,468	1,173,830
Other borrowings		20,000
Accrued interest payable	9,360	10,855
Long-term debt	83,527	83,762
Level 3
Financial Assets:
Loans receivable, net	15,255,089	14,743,218
Financial Liabilities:
Time deposits	$ 5,941,410	$ 6,115,530