CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Statement of Comprehensive Income [Abstract]
Net income	$ 13,632	$ 12,404
Other comprehensive (loss) income, net of tax:
Change in unrealized appreciation (depreciation) of available-for-sale securities	4,016	(1,931)
Reclassification adjustment for realized losses (gains) included in net income	(963)	0
Income tax effect	(1,146)	725
Other comprehensive income (loss), net of tax	1,907	(1,206)
Comprehensive income	$ 15,539	$ 11,198