Loans (Details 10) (USD $) In Thousands, unless otherwise specified	3 Months Ended	9 Months Ended
Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011	Dec. 31, 2011
Schedule of allowance and recorded investment related to financing receivables segregated by portfolio segment
Beginning balance	$ 86,711	$ 89,733	$ 88,333	$ 89,530
Provision for loan losses	4,500	6,400	13,500	20,900
Charge-offs	(7,596)	(8,839)	(20,315)	(25,787)
Recoveries	1,079	1,419	3,176	4,070
Ending balance	84,694	88,713	84,694	88,713
Allowance for loan losses
Loans individually evaluated for impairment related to allowance for loan losses	8,659	9,326	8,659	9,326	9,286
Loans collectively evaluated for impairment related to allowance for loan losses	75,535	78,087	75,535	78,087	77,447
Loans acquired with deteriorated credit quality related to allowance for loan losses	500	1,300	500	1,300	1,600
Total	84,694	88,713	84,694	88,713
Loans individually evaluated for impairment related to recorded investment (loan balance)	104,053	109,346	104,053	109,346	105,806
Loans collectively evaluated for impairment related to recorded investment (loan balance)	3,502,494	3,155,708	3,502,494	3,155,708	3,232,696
Loans acquired with deteriorated credit quality related to recorded investment (loan balance)	412,612	495,372	412,612	495,372	492,783
Total loans	4,019,159	3,760,426	4,019,159	3,760,426	3,831,285
Commercial Loan Portfolio [Member]
Schedule of allowance and recorded investment related to financing receivables segregated by portfolio segment
Beginning balance	53,759	58,572	55,645	59,443
Provision for loan losses	2,365	2,258	6,003	11,348
Charge-offs	(4,754)	(5,439)	(11,330)	(16,629)
Recoveries	460	899	1,512	2,128
Ending balance	51,830	56,290	51,830	56,290
Allowance for loan losses
Loans individually evaluated for impairment related to allowance for loan losses	8,010	8,708	8,010	8,708	8,582
Loans collectively evaluated for impairment related to allowance for loan losses	43,820	46,282	43,820	46,282	45,863
Loans acquired with deteriorated credit quality related to allowance for loan losses	0	1,300	0	1,300	1,200
Total	51,830	56,290	51,830	56,290
Loans individually evaluated for impairment related to recorded investment (loan balance)	84,495	87,930	84,495	87,930	80,794
Loans collectively evaluated for impairment related to recorded investment (loan balance)	1,721,367	1,525,093	1,721,367	1,525,093	1,582,379
Loans acquired with deteriorated credit quality related to recorded investment (loan balance)	354,031	421,867	354,031	421,867	422,152
Total loans	2,159,893	2,034,890	2,159,893	2,034,890	2,085,325
Consumer Loan Portfolio [Member]
Schedule of allowance and recorded investment related to financing receivables segregated by portfolio segment
Beginning balance	29,784	29,283	29,166	27,338
Provision for loan losses	1,765	2,296	7,481	8,577
Charge-offs	(2,842)	(3,400)	(8,985)	(9,158)
Recoveries	619	520	1,664	1,942
Ending balance	29,326	28,699	29,326	28,699
Allowance for loan losses
Loans individually evaluated for impairment related to allowance for loan losses	649	618	649	618	704
Loans collectively evaluated for impairment related to allowance for loan losses	28,177	28,081	28,177	28,081	28,062
Loans acquired with deteriorated credit quality related to allowance for loan losses	500	0	500	0	400
Total	29,326	28,699	29,326	28,699
Loans individually evaluated for impairment related to recorded investment (loan balance)	19,558	21,416	19,558	21,416	25,012
Loans collectively evaluated for impairment related to recorded investment (loan balance)	1,781,127	1,630,615	1,781,127	1,630,615	1,650,317
Loans acquired with deteriorated credit quality related to recorded investment (loan balance)	58,581	73,505	58,581	73,505	70,631
Total loans	1,859,266	1,725,536	1,859,266	1,725,536	1,745,960
Unallocated [Member]
Schedule of allowance and recorded investment related to financing receivables segregated by portfolio segment
Beginning balance	3,168	1,878	3,522	2,749
Provision for loan losses	370	1,846	16	975
Charge-offs	0	0	0	0
Recoveries	0	0	0	0
Ending balance	3,538	3,724	3,538	3,724
Allowance for loan losses
Loans individually evaluated for impairment related to allowance for loan losses	0	0	0	0	0
Loans collectively evaluated for impairment related to allowance for loan losses	3,538	3,724	3,538	3,724	3,522
Loans acquired with deteriorated credit quality related to allowance for loan losses	0	0	0	0	0
Total	3,538	3,724	3,538	3,724
Loans individually evaluated for impairment related to recorded investment (loan balance)	0	0	0	0	0
Loans collectively evaluated for impairment related to recorded investment (loan balance)	0	0	0	0	0
Loans acquired with deteriorated credit quality related to recorded investment (loan balance)	0	0	0	0	0
Total loans	$ 0	$ 0	$ 0	$ 0	$ 0

The balance of financing receivables that were acquired with deteriorated credit quality.

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