Loans (Schedule of the Allowance for Loan Losses) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
Mar. 31, 2013	Mar. 31, 2012	Dec. 31, 2012
Schedule of allowance and recorded investment related to financing receivables segregated by portfolio segment
Beginning balance	$ 84,491	$ 88,333
Provision for loan losses	3,000	5,000
Charge-offs	(5,474)	(6,547)
Recoveries	817	999
Ending balance	82,834	87,785
Allowance for loan losses
Loans individually evaluated for impairment related to allowance for loan losses	6,184	9,887	8,108
Loans collectively evaluated for impairment related to allowance for loan losses	76,150	75,698	75,883
Loans acquired with deteriorated credit quality related to allowance for loan losses	500	2,200	500
Total	82,834	87,785
Loans individually evaluated for impairment related to recorded investment (loan balance)	101,946	106,048	106,228
Loans collectively evaluated for impairment related to recorded investment (loan balance)	3,709,043	3,264,231	3,668,912
Loans acquired with deteriorated credit quality related to recorded investment (loan balance)	374,272	472,819	392,595
Total loans	4,185,261	3,843,098	4,167,735
Commercial Loan Portfolio [Member]
Schedule of allowance and recorded investment related to financing receivables segregated by portfolio segment
Beginning balance	49,975	55,645
Provision for loan losses	2,437	2,037
Charge-offs	(3,516)	(3,379)
Recoveries	211	614
Ending balance	49,107	54,917
Allowance for loan losses
Loans individually evaluated for impairment related to allowance for loan losses	5,522	9,177	7,450
Loans collectively evaluated for impairment related to allowance for loan losses	43,585	44,140	42,525
Loans acquired with deteriorated credit quality related to allowance for loan losses	0	1,600	0
Total	49,107	54,917
Loans individually evaluated for impairment related to recorded investment (loan balance)	84,650	81,901	87,327
Loans collectively evaluated for impairment related to recorded investment (loan balance)	1,892,452	1,612,441	1,840,629
Loans acquired with deteriorated credit quality related to recorded investment (loan balance)	321,403	406,543	336,864
Total loans	2,298,505	2,100,885	2,264,820
Consumer Loan Portfolio [Member]
Schedule of allowance and recorded investment related to financing receivables segregated by portfolio segment
Beginning balance	29,333	29,166
Provision for loan losses	871	1,343
Charge-offs	(1,958)	(3,168)
Recoveries	606	385
Ending balance	28,852	27,726
Allowance for loan losses
Loans individually evaluated for impairment related to allowance for loan losses	662	710	658
Loans collectively evaluated for impairment related to allowance for loan losses	27,690	26,416	28,175
Loans acquired with deteriorated credit quality related to allowance for loan losses	500	600	500
Total	28,852	27,726
Loans individually evaluated for impairment related to recorded investment (loan balance)	17,296	24,147	18,901
Loans collectively evaluated for impairment related to recorded investment (loan balance)	1,816,591	1,651,790	1,828,283
Loans acquired with deteriorated credit quality related to recorded investment (loan balance)	52,869	66,276	55,731
Total loans	1,886,756	1,742,213	1,902,915
Unallocated [Member]
Schedule of allowance and recorded investment related to financing receivables segregated by portfolio segment
Beginning balance	5,183	3,522
Provision for loan losses	(308)	1,620
Charge-offs	0	0
Recoveries	0	0
Ending balance	4,875	5,142
Allowance for loan losses
Loans individually evaluated for impairment related to allowance for loan losses	0	0	0
Loans collectively evaluated for impairment related to allowance for loan losses	4,875	5,142	5,183
Loans acquired with deteriorated credit quality related to allowance for loan losses	0	0	0
Total	4,875	5,142
Loans individually evaluated for impairment related to recorded investment (loan balance)	0	0	0
Loans collectively evaluated for impairment related to recorded investment (loan balance)	0	0	0
Loans acquired with deteriorated credit quality related to recorded investment (loan balance)	0	0	0
Total loans	$ 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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