FAIR VALUE MEASUREMENTS (Details 5) (USD $)	3 Months Ended
	Mar. 31, 2013	Dec. 31, 2012	Mar. 31, 2012
Financial Assets:
Interest-earning deposits in financial institutions	$ 41,019,000	$ 75,393,000
Loans and leases, net	3,374,744,000	3,498,329,000	3,450,813,000
Non-covered impaired loans
Nonaccrual loans	41,900,000	39,300,000
Amount of nonaccrual loans writtendown to fair values through chargeoffs	2,300,000
Other real estate owned
Period of appraisals for Level 2 measurement	12 months
Minimum
Non-covered impaired loans
Threshold of unpaid principal balance of non-covered nonaccrual loans for individual evaluation of impairment	250,000
Maximum
Non-covered impaired loans
Threshold of unpaid principal balance of non-covered nonaccrual loans for collective evaluation of impairment	250,000
Total
Financial Assets:
Cash and due from banks	90,659,000	89,011,000
Interest-earning deposits in financial institutions	41,019,000	75,393,000
Securities available-for-sale	1,362,777,000	1,355,385,000
Investment in FHLB stock	33,400,000	37,126,000
Loans and leases, net	3,415,761,000	3,551,674,000
SBA loan servicing asset	956,000	1,000,000
Financial Liabilities:
Demand, money market, interest checking and savings deposits	3,796,438,000	3,888,794,000
Time deposits	758,995,000	823,912,000
Borrowings	11,196,000	12,611,000
Subordinated debentures	108,186,000	108,186,000
Level 1
Financial Assets:
Cash and due from banks	90,659,000	89,011,000
Interest-earning deposits in financial institutions	41,019,000	75,393,000
Securities available-for-sale	9,856,000	8,985,000
Level 2
Financial Assets:
Securities available-for-sale	1,309,136,000	1,301,716,000
Investment in FHLB stock	33,400,000	37,126,000
Loans and leases, net	6,226,000	4,975,000
Financial Liabilities:
Demand, money market, interest checking and savings deposits	3,796,438,000	3,888,794,000
Time deposits	758,995,000	823,912,000
Borrowings	11,196,000	12,611,000
Subordinated debentures	108,186,000	108,186,000
Level 3
Financial Assets:
Securities available-for-sale	43,785,000	44,684,000
Loans and leases, net	3,409,535,000	3,546,699,000
SBA loan servicing asset	956,000	1,000,000
Carrying or Contract Amount
Financial Assets:
Cash and due from banks	90,659,000	89,011,000
Interest-earning deposits in financial institutions	41,019,000	75,393,000
Securities available-for-sale	1,362,777,000	1,355,385,000
Investment in FHLB stock	33,400,000	37,126,000
Loans and leases, net	3,374,744,000	3,498,329,000
SBA loan servicing asset	956,000	1,000,000
Financial Liabilities:
Demand, money market, interest checking and savings deposits	3,796,438,000	3,888,794,000
Time deposits	756,792,000	820,327,000
Borrowings	11,196,000	12,591,000
Subordinated debentures	$ 108,250,000	$ 108,250,000