Loans, Allowance for Credit Losses, and Credit Quality Changes in the Allowance for Loan Losses (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
Sep. 30, 2015	Dec. 31, 2014
Changes in the allowance for loan losses
Loans and Leases Receivable, Allowance, Beginning Balance	$ 266,302	$ 268,315
Provision for loan losses	18,500	13,000
Charge offs	(39,539)	(44,096)
Recoveries	17,273	29,083
Net charge offs	(22,266)	(15,013)
Loans and Leases Receivable, Allowance, Ending Balance	262,536	266,302
Changes in the allowance for unfunded commitments
Allowance for Credit Losses	286,436	291,202
Reserve for Off-balance Sheet Activities [Member]
Changes in the allowance for unfunded commitments
Balance at beginning of period	24,900	21,900
Provision for unfunded commitments	(1,000)	3,000
Balance at end of period	$ 23,900	$ 24,900

Allowance for Credit Losses

No definition available.

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- Definition

Amount of recovery of loans and lease receivables which had previously been fully or partially written-off as bad debts.

+ References

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A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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Amount of loans and leases that have been written off from both loan receivables and allowance reserve for credit loss.

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Amount, after recoveries, of loans and leases that have been written-off.

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No definition available.

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- Definition

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.

+ References

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Amount of expense related to estimated loss from loan and lease transactions.

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Amount of expense related to credit loss from transactions other than loan and lease transactions.

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Total of allowances and reserves, the valuation and qualifying accounts that are either netted against the cost of an asset (in order to value it at its carrying value) or that reflect a liability established to represent expected future costs.

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