CONSOLIDATED STATEMENTS OF OTHER COMPREHENSIVE INCOME (USD $) In Thousands, unless otherwise specified	3 Months Ended
Mar. 31, 2015	Mar. 31, 2014
CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME
Net income	$ 7,761us-gaap_NetIncomeLoss	$ 7,887us-gaap_NetIncomeLoss
Unrealized net gains on securities:
Unrealized net holding gains arising during period	4,031	857
Reclassification adjustment for (gains) included in net income	(1)	(43)
Other comprehensive income, before tax	4,030	814
Income tax expense related to items of other comprehensive income	1,614	335
Other comprehensive income, net of tax	2,416	479
Comprehensive income	$ 10,177us-gaap_ComprehensiveIncomeNetOfTax	$ 8,366us-gaap_ComprehensiveIncomeNetOfTax

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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Amount before tax of reclassification adjustment from accumulated other comprehensive income for unrealized gain (loss) realized upon the sale of available-for-sale securities.

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

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