CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME
Net income	$ 33,744	$ 41,143	$ 33,188
Other comprehensive income (loss), before tax:
Changes in unrealized gains and losses on securities available-for-sale	25,287	(20,012)	4,419
Changes in unrealized gains and losses on derivative hedges	(1,010)	8,666	(2,072)
Changes in unrealized gains and losses on terminated swaps	3,237	942	942
Changes in unrealized gains and losses on pension	(2,308)	1,282	(136)
Total other comprehensive income (loss), before tax	25,206	(9,122)	3,153
Income taxes related to other comprehensive income (loss):
Changes in unrealized gains and losses on securities available-for-sale	(9,595)	7,524	(1,667)
Changes in unrealized gains and losses on derivative hedges	407	(3,474)	688
Changes in unrealized gains and losses on terminated swaps	(1,312)	(489)	(324)
Changes in unrealized gains and losses on pension	930	(517)	56
Total income tax (expense) benefit related to other comprehensive income (loss)	(9,570)	3,044	(1,247)
Total other comprehensive income (loss)	15,636	(6,078)	1,906
Total comprehensive income	$ 49,380us-gaap_ComprehensiveIncomeNetOfTax	$ 35,065us-gaap_ComprehensiveIncomeNetOfTax	$ 35,094us-gaap_ComprehensiveIncomeNetOfTax

Represents the before tax amount of the change in accumulated gain (loss) from terminated swaps.

No definition available.

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Represents the tax effect of the change in accumulated gain (loss) from terminated swaps.

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Amount after tax of increase (decrease) in equity from transactions and other events and circumstances from net income and other comprehensive income, attributable to parent entity. Excludes changes in equity resulting from investments by owners and distributions to owners.

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Net income after adjustments for dividends on preferred stock (declared in the period) and/or cumulative preferred stock (accumulated for the period).

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Amount before tax of other comprehensive income (loss) attributable to parent entity.

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Amount after tax of other comprehensive income (loss) attributable to parent entity.

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Amount before tax, after reclassification adjustments, of (increase) decrease in accumulated other comprehensive (income) loss related to pension and other postretirement defined benefit plans.

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Amount of tax (expense) benefit, after reclassification adjustments, of (increase) decrease in accumulated other comprehensive (income) loss related to pension and other postretirement defined benefit plans.

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Amount of tax expense (benefit) allocated to other comprehensive income (loss) attributable to parent entity.

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Amount before tax of increase (decrease) in accumulated gain (loss) from derivative instruments designated and qualifying as the effective portion of cash flow hedges and an entity's share of an equity investee's increase (decrease) in deferred hedging gain (loss).

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Amount of tax expense (benefit), before reclassification adjustments, related to increase (decrease) in accumulated gain (loss) from derivative instruments designated and qualifying as the effective portion of cash flow hedges and an entity's share of an equity investee's increase (decrease) in deferred hedging gain (loss).

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Amount before tax and reclassification adjustments of unrealized holding gain (loss) on available-for-sale securities.

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Amount of tax expense (benefit) before reclassification adjustments of unrealized holding gain (loss) on available-for-sale securities.

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