FAIR VALUE DISCLOSURES (Details 3) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Investment securities [Abstract]
Available for sale	$ 1,604,287	$ 2,043,727
Held-to-maturity Securities, Estimated Fair Value	748,478	637,024
Estimate of Fair Value, Fair Value Disclosure [Member]
Financial Assets:
Cash and Cash Equivalents, Fair Value Disclosure	714,155	518,846
Investment securities [Abstract]
Available for sale	1,604,287	2,043,727
Held-to-maturity Securities, Estimated Fair Value	748,478	637,024
Loans held for portfolio, Estimated Fair Value	2,478,309	2,572,256
Loans Held-for-sale, Estimated Fair Value	28,313	66,133
FRB and FHLB stock, Estimated Fair Value	27,137	27,329
Derivative assets, Estimated Fair Value	113	1,619
Accrued interest receivable, Estimated Fair Value	17,738	18,284
Assets Of discontinued operations, Estimated Fair Value	38,511	6,706
Financial Liabilities:
Noninterest-bearing demand Estimated Fair Value	1,224,595	1,327,183
Interest-bearing demand, Estimated Fair Value	677,900	1,000,666
Savings and money market, Estimated Fair Value	1,852,268	1,880,271
Time deposits, Estimated Fair Value	1,081,334	1,286,730
Other borrowings, Estimated Fair Value	37,077	26,025
Derivative liabilities, Estimated Fair Value	7	87
Accrued interest payable, Estimated Fair Value	59,521	48,541
Subordinated debentures, Estimated Fair Value	269,610	254,984
Liabilities Of discontinued operations, Estimated Fair Value	500,401	155,711
Off-Balance Sheet Financial Instruments:
Commitments to extend credit, standby letters of credit and financial guarantees, Estimated Fair Value	(2,715)	(2,779)
Estimate of Fair Value, Fair Value Disclosure [Member] | Fair Value, Inputs, Level 1 [Member]
Financial Assets:
Cash and Cash Equivalents, Fair Value Disclosure	714,155	518,846
Investment securities [Abstract]
Available for sale	1,456	1,022
Held-to-maturity Securities, Estimated Fair Value	0	0
Loans held for portfolio, Estimated Fair Value	0	0
Loans Held-for-sale, Estimated Fair Value	0	0
FRB and FHLB stock, Estimated Fair Value	27,137	27,329
Derivative assets, Estimated Fair Value	0	0
Accrued interest receivable, Estimated Fair Value	17,738	18,284
Assets Of discontinued operations, Estimated Fair Value	0	0
Financial Liabilities:
Noninterest-bearing demand Estimated Fair Value	1,224,595	1,327,183
Interest-bearing demand, Estimated Fair Value	677,900	1,000,666
Savings and money market, Estimated Fair Value	1,852,268	1,880,271
Time deposits, Estimated Fair Value	0	0
Other borrowings, Estimated Fair Value	37,077	26,025
Derivative liabilities, Estimated Fair Value	0	0
Accrued interest payable, Estimated Fair Value	59,521	48,541
Subordinated debentures, Estimated Fair Value	0	0
Liabilities Of discontinued operations, Estimated Fair Value	0	0
Off-Balance Sheet Financial Instruments:
Commitments to extend credit, standby letters of credit and financial guarantees, Estimated Fair Value	0	0
Estimate of Fair Value, Fair Value Disclosure [Member] | Fair Value, Inputs, Level 2 [Member]
Financial Assets:
Cash and Cash Equivalents, Fair Value Disclosure	0	0
Investment securities [Abstract]
Available for sale	1,602,831	2,042,705
Held-to-maturity Securities, Estimated Fair Value	748,478	637,024
Loans held for portfolio, Estimated Fair Value	0	0
Loans Held-for-sale, Estimated Fair Value	28,313	66,133
FRB and FHLB stock, Estimated Fair Value	0	0
Derivative assets, Estimated Fair Value	113	1,619
Accrued interest receivable, Estimated Fair Value	0	0
Assets Of discontinued operations, Estimated Fair Value	38,511	6,706
Financial Liabilities:
Noninterest-bearing demand Estimated Fair Value	0	0
Interest-bearing demand, Estimated Fair Value	0	0
Savings and money market, Estimated Fair Value	0	0
Time deposits, Estimated Fair Value	0	0
Other borrowings, Estimated Fair Value	0	0
Derivative liabilities, Estimated Fair Value	7	87
Accrued interest payable, Estimated Fair Value	0	0
Subordinated debentures, Estimated Fair Value	0	0
Liabilities Of discontinued operations, Estimated Fair Value	500,401	155,711
Off-Balance Sheet Financial Instruments:
Commitments to extend credit, standby letters of credit and financial guarantees, Estimated Fair Value	0	0
Estimate of Fair Value, Fair Value Disclosure [Member] | Fair Value, Inputs, Level 3 [Member]
Financial Assets:
Cash and Cash Equivalents, Fair Value Disclosure	0	0
Investment securities [Abstract]
Available for sale	0	0
Held-to-maturity Securities, Estimated Fair Value	0	0
Loans held for portfolio, Estimated Fair Value	2,478,309	2,572,256
Loans Held-for-sale, Estimated Fair Value	0	0
FRB and FHLB stock, Estimated Fair Value	0	0
Derivative assets, Estimated Fair Value	0	0
Accrued interest receivable, Estimated Fair Value	0	0
Assets Of discontinued operations, Estimated Fair Value	0	0
Financial Liabilities:
Noninterest-bearing demand Estimated Fair Value	0	0
Interest-bearing demand, Estimated Fair Value	0	0
Savings and money market, Estimated Fair Value	0	0
Time deposits, Estimated Fair Value	1,081,334	1,286,730
Other borrowings, Estimated Fair Value	0	0
Derivative liabilities, Estimated Fair Value	0	0
Accrued interest payable, Estimated Fair Value	0	0
Subordinated debentures, Estimated Fair Value	269,610	254,984
Liabilities Of discontinued operations, Estimated Fair Value	0	0
Off-Balance Sheet Financial Instruments:
Commitments to extend credit, standby letters of credit and financial guarantees, Estimated Fair Value	(2,715)	(2,779)
Carrying (Reported) Amount, Fair Value Disclosure [Member]
Financial Assets:
Cash and Cash Equivalents, Fair Value Disclosure	714,155	518,846
Investment securities [Abstract]
Available for sale	1,604,287	2,043,727
Held-to-maturity Securities, Estimated Fair Value	764,304	631,553
Loans held for portfolio, Estimated Fair Value	2,674,340	2,773,012
Loans Held-for-sale, Estimated Fair Value	28,313	66,133
FRB and FHLB stock, Estimated Fair Value	27,137	27,329
Derivative assets, Estimated Fair Value	113	1,619
Accrued interest receivable, Estimated Fair Value	17,738	18,284
Assets Of discontinued operations, Estimated Fair Value	38,511	6,706
Financial Liabilities:
Noninterest-bearing demand Estimated Fair Value	1,224,595	1,327,183
Interest-bearing demand, Estimated Fair Value	677,900	1,000,666
Savings and money market, Estimated Fair Value	1,852,268	1,880,271
Time deposits, Estimated Fair Value	1,080,659	1,284,727
Other borrowings, Estimated Fair Value	37,077	26,025
Derivative liabilities, Estimated Fair Value	7	87
Accrued interest payable, Estimated Fair Value	59,521	48,541
Subordinated debentures, Estimated Fair Value	354,191	354,133
Liabilities Of discontinued operations, Estimated Fair Value	549,155	155,711
Off-Balance Sheet Financial Instruments:
Commitments to extend credit, standby letters of credit and financial guarantees, Estimated Fair Value	$ (2,715)	$ (2,779)