FAIR VALUE DISCLOSURES (Details 3) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011	Jun. 30, 2011	Dec. 31, 2010
Financial Assets:
Cash and Cash Equivalents, Fair Value Disclosure	$ 321,707	$ 472,011
Cash and cash equivalents	321,707	472,011	628,756	995,758
Marketable Securities [Abstract]
Available for sale	2,099,897	2,457,887
Held to maturity	741,727	12,817
Loans held for portfolio	2,864,929	3,115,130
Loans held for sale	46,289	31,111
FRB and FHLB stock	26,115	27,078
Derivative instruments	2,075	1,022
Accrued interest receivable	19,512	21,050
Assets of discontinued operations	20,501	21,009
Available-for-sale Securities, Estimated Fair Value	2,099,897	2,457,887
Held-to-maturity Securities, Estimated Fair Value	741,973	13,424
Loans Held For Portfolio, Estimated Fair Value	2,564,786	2,811,538
Loans Held-for-sale, Estimated Fair Value	46,289	31,111
FRB and FHLB stock, Estimated Fair Value	26,115	27,078
Derivative Assets, Estimated Fair Value	2,075	1,022
Accrued interest receivable, Estimated Fair Value	19,512	21,050
Assets Of Discontinued Operations, Estimated Fair Value	20,501	21,009
Financial Liabilities:
Noninterest-bearing demand	1,287,222	1,209,759
Interest-bearing demand	907,381	884,168
Savings and money market	1,854,808	1,893,560
Time Deposits	1,341,852	1,464,343
Other borrowings	37,814	50,910
Derivative instruments	479	1,114
Accrued interest payable	41,289	34,285
Subordinated debentures	354,095	354,057
Liabilities of discontinued operations	339,924	346,282
Noninterest-Bearing Demand Estimated Fair Value	1,287,222	1,209,759
Interest-Bearing Demand, Estimated Fair Value	907,381	884,168
Savings and Money Market, Estimated Fair Value	1,854,808	1,893,560
Time Deposits, Estimated Fair Value	1,343,387	1,467,548
Other borrowings, Estimated Fair Value	37,814	50,910
Derivative Instruments, Estimated Fair Value	479	1,114
Accrued Interest Payable, Estimated Fair Value	41,289	34,285
Subordinated debentures, Estimated Fair Value	231,425	204,502
Liabilities Of Discontinued Operations, Estimated Fair Value	333,314	339,527
Off-Balance Sheet Financial Instruments:
Commitments to extend credit, standby letters of credit and financial guarantees	(2,779)	(2,785)
Commitments to extend credit, standby letters of credit and financial guarantees, Estimated Fair Value	(2,779)	(2,785)
Fair Value, Inputs, Level 1 [Member]
Financial Assets:
Cash and Cash Equivalents, Fair Value Disclosure	321,707
Marketable Securities [Abstract]
Available-for-sale Securities, Estimated Fair Value	1,029
Held-to-maturity Securities, Estimated Fair Value	0
Loans Held For Portfolio, Estimated Fair Value	0
FRB and FHLB stock, Estimated Fair Value	26,115
Derivative Assets, Estimated Fair Value	0
Accrued interest receivable, Estimated Fair Value	19,512
Assets Of Discontinued Operations, Estimated Fair Value	0
Financial Liabilities:
Noninterest-Bearing Demand Estimated Fair Value	1,287,222
Interest-Bearing Demand, Estimated Fair Value	907,381
Savings and Money Market, Estimated Fair Value	1,854,808
Time Deposits, Estimated Fair Value	0
Other borrowings, Estimated Fair Value	37,814
Derivative Instruments, Estimated Fair Value	0
Accrued Interest Payable, Estimated Fair Value	41,289
Subordinated debentures, Estimated Fair Value	0
Liabilities Of Discontinued Operations, Estimated Fair Value	0
Off-Balance Sheet Financial Instruments:
Commitments to extend credit, standby letters of credit and financial guarantees, Estimated Fair Value	0
Fair Value, Inputs, Level 2 [Member]
Financial Assets:
Cash and Cash Equivalents, Fair Value Disclosure	0
Marketable Securities [Abstract]
Available-for-sale Securities, Estimated Fair Value	2,098,868
Held-to-maturity Securities, Estimated Fair Value	741,973
Loans Held For Portfolio, Estimated Fair Value	0
Loans Held-for-sale, Estimated Fair Value	46,289
FRB and FHLB stock, Estimated Fair Value	0
Derivative Assets, Estimated Fair Value	2,075
Accrued interest receivable, Estimated Fair Value	0
Assets Of Discontinued Operations, Estimated Fair Value	20,501
Financial Liabilities:
Noninterest-Bearing Demand Estimated Fair Value	0
Interest-Bearing Demand, Estimated Fair Value	0
Savings and Money Market, Estimated Fair Value	0
Time Deposits, Estimated Fair Value	0
Other borrowings, Estimated Fair Value	0
Derivative Instruments, Estimated Fair Value	479
Accrued Interest Payable, Estimated Fair Value	0
Subordinated debentures, Estimated Fair Value	0
Liabilities Of Discontinued Operations, Estimated Fair Value	333,314
Off-Balance Sheet Financial Instruments:
Commitments to extend credit, standby letters of credit and financial guarantees, Estimated Fair Value	0
Fair Value, Inputs, Level 3 [Member]
Financial Assets:
Cash and Cash Equivalents, Fair Value Disclosure	0
Marketable Securities [Abstract]
Available-for-sale Securities, Estimated Fair Value	0
Held-to-maturity Securities, Estimated Fair Value	0
Loans Held For Portfolio, Estimated Fair Value	2,564,786
Loans Held-for-sale, Estimated Fair Value	0
FRB and FHLB stock, Estimated Fair Value	0
Derivative Assets, Estimated Fair Value	0
Accrued interest receivable, Estimated Fair Value	0
Assets Of Discontinued Operations, Estimated Fair Value	0
Financial Liabilities:
Noninterest-Bearing Demand Estimated Fair Value	0
Interest-Bearing Demand, Estimated Fair Value	0
Savings and Money Market, Estimated Fair Value	0
Time Deposits, Estimated Fair Value	1,343,387
Other borrowings, Estimated Fair Value	0
Derivative Instruments, Estimated Fair Value	0
Accrued Interest Payable, Estimated Fair Value	0
Subordinated debentures, Estimated Fair Value	231,425
Liabilities Of Discontinued Operations, Estimated Fair Value	0
Off-Balance Sheet Financial Instruments:
Commitments to extend credit, standby letters of credit and financial guarantees, Estimated Fair Value	$ (2,779)