CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) (USD $) In Thousands, unless otherwise specified	3 Months Ended
Mar. 31, 2015	Mar. 31, 2014
Statement of Comprehensive Income [Abstract]
NET INCOME	$ 12,134us-gaap_NetIncomeLoss	$ 10,549us-gaap_NetIncomeLoss
OTHER COMPREHENSIVE INCOME, NET OF INCOME TAXES:
Unrealized holding gains on available-for-sale securities arising during the period	2,283	2,506
Income tax expense related to available-for-sale securities unrealized holding gains	(822)	(902)
Reclassification for net gains on available-for-sale securities realized in earnings	(104)	(34)
Income tax benefit related to available-for-sale securities realized gains	38	12
Other comprehensive income	1,395	1,582
COMPREHENSIVE INCOME	$ 13,529us-gaap_ComprehensiveIncomeNetOfTax	$ 12,131us-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 after tax and reclassification adjustments of other comprehensive income (loss).

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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 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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