Loans (Schedule of the Allowance for Loan Losses) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended	6 Months Ended
Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012	Dec. 31, 2012
Schedule of allowance and recorded investment related to financing receivables segregated by portfolio segment
Beginning balance	$ 82,834	$ 87,785	$ 84,491	$ 88,333
Provision for loan losses	3,000	4,000	6,000	9,000
Charge-offs	(5,361)	(6,172)	(10,835)	(12,719)
Recoveries	1,711	1,098	2,528	2,097
Ending balance	82,184	86,711	82,184	86,711
Allowance for loan losses
Loans individually evaluated for impairment related to allowance for loan losses	4,434	8,138	4,434	8,138	8,108
Loans collectively evaluated for impairment related to allowance for loan losses	77,250	76,373	77,250	76,373	75,883
Loans acquired with deteriorated credit quality related to allowance for loan losses	500	2,200	500	2,200	500
Total	82,184	86,711	82,184	86,711
Loans individually evaluated for impairment related to recorded investment (loan balance)	98,210	100,021	98,210	100,021	106,228
Loans collectively evaluated for impairment related to recorded investment (loan balance)	3,892,423	3,415,089	3,892,423	3,415,089	3,668,912
Loans acquired with deteriorated credit quality related to recorded investment (loan balance)	345,238	447,232	345,238	447,232	392,595
Total loans	4,335,871	3,962,342	4,335,871	3,962,342	4,167,735
Commercial Loan Portfolio [Member]
Schedule of allowance and recorded investment related to financing receivables segregated by portfolio segment
Beginning balance	49,107	54,917	49,975	55,645
Provision for loan losses	568	1,601	3,005	3,638
Charge-offs	(3,221)	(3,197)	(6,737)	(6,576)
Recoveries	1,326	438	1,537	1,052
Ending balance	47,780	53,759	47,780	53,759
Allowance for loan losses
Loans individually evaluated for impairment related to allowance for loan losses	3,852	7,461	3,852	7,461	7,450
Loans collectively evaluated for impairment related to allowance for loan losses	43,928	44,698	43,928	44,698	42,525
Loans acquired with deteriorated credit quality related to allowance for loan losses	0	1,600	0	1,600	0
Total	47,780	53,759	47,780	53,759
Loans individually evaluated for impairment related to recorded investment (loan balance)	80,804	81,622	80,804	81,622	87,327
Loans collectively evaluated for impairment related to recorded investment (loan balance)	1,989,486	1,661,425	1,989,486	1,661,425	1,840,629
Loans acquired with deteriorated credit quality related to recorded investment (loan balance)	294,580	386,187	294,580	386,187	336,864
Total loans	2,364,870	2,129,234	2,364,870	2,129,234	2,264,820
Consumer Loan Portfolio [Member]
Schedule of allowance and recorded investment related to financing receivables segregated by portfolio segment
Beginning balance	28,852	27,726	29,333	29,166
Provision for loan losses	1,648	4,373	2,519	5,716
Charge-offs	(2,140)	(2,975)	(4,098)	(6,143)
Recoveries	385	660	991	1,045
Ending balance	28,745	29,784	28,745	29,784
Allowance for loan losses
Loans individually evaluated for impairment related to allowance for loan losses	582	677	582	677	658
Loans collectively evaluated for impairment related to allowance for loan losses	27,663	28,507	27,663	28,507	28,175
Loans acquired with deteriorated credit quality related to allowance for loan losses	500	600	500	600	500
Total	28,745	29,784	28,745	29,784
Loans individually evaluated for impairment related to recorded investment (loan balance)	17,406	18,399	17,406	18,399	18,901
Loans collectively evaluated for impairment related to recorded investment (loan balance)	1,902,937	1,753,664	1,902,937	1,753,664	1,828,283
Loans acquired with deteriorated credit quality related to recorded investment (loan balance)	50,658	61,045	50,658	61,045	55,731
Total loans	1,971,001	1,833,108	1,971,001	1,833,108	1,902,915
Unallocated [Member]
Schedule of allowance and recorded investment related to financing receivables segregated by portfolio segment
Beginning balance	4,875	5,142	5,183	3,522
Provision for loan losses	784	(1,974)	476	(354)
Charge-offs	0	0	0	0
Recoveries	0	0	0	0
Ending balance	5,659	3,168	5,659	3,168
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	5,659	3,168	5,659	3,168	5,183
Loans acquired with deteriorated credit quality related to allowance for loan losses	0	0	0	0	0
Total	5,659	3,168	5,659	3,168
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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Amount of recovery of financing receivables doubtful of collection that were previously charged off.

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Amount of direct write-downs of financing receivables charged against the allowance.

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Amount of allowance to cover probable credit losses on loans and leases. Includes carryover of or adjustments to the allowance for loan losses in connection with business combinations. Excludes allowance for loans and leases covered under loss sharing agreements.

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Amount before allowance of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Includes deferred interest and fees, undisbursed portion of loan balance, unamortized costs and premiums and discounts from face amounts. Excludes loans and leases covered under loss sharing agreements.

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The sum of the periodic provision charged to earnings, based on an assessment of uncollectibility from the counterparty on account of loan, lease or other credit losses, to reduce these accounts to the amount that approximates their net realizable value.

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