Loans and Asset Quality Information (Details 10) (USD $) In Thousands, unless otherwise specified	3 Months Ended	9 Months Ended	12 Months Ended
Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011	Dec. 31, 2011
Activity in the allowance for loan losses for covered loans
Provisions	$ 7,073	$ 9,146	$ 35,095	$ 31,423
Ending balance - total	2,137,074	2,058,724	2,137,074	2,058,724	2,069,152
Covered
Activity in the allowance for loan losses for covered loans
Beginning balance	5,931	5,540	5,808	11,155	11,155
Charge-offs	(2,640)	(4,988)	(6,788)	(17,703)	(18,123)
Recoveries
Provisions	1,103	2,705	5,374	9,805	12,776
Ending balance	4,394	3,257	4,394	3,257	5,808
Individually evaluated for impairment	4,394	3,257	4,394	3,257	5,808
Collectively evaluated for impairment
Loans acquired with deteriorated credit quality	17		17		327
Ending balance - total	303,997	373,824	303,997	373,824	361,234
Individually evaluated for impairment	57,607	33,163	57,607	33,163	44,723
Collectively evaluated for impairment	246,390	340,661	246,390	340,661	316,511
Loans acquired with deteriorated credit quality	$ 4,745	$ 9,037	$ 4,745	$ 9,037	$ 7,864

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

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A valuation allowance for financing receivables that are expected to be uncollectible.

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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 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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