CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Statement of Comprehensive Income [Abstract]
Net income	$ 14,947	$ 14,896	$ 43,073	$ 41,242
Other comprehensive income (loss):
Change in unrealized (depreciation) appreciation of available-for-sale securities	(2,507)	1,853	4,268	(16,881)
Reclassification adjustment for realized losses (gains) included in net income	0	28	(963)	28
Income tax effect	941	(706)	(1,241)	6,327
Other comprehensive (loss) income, net of tax	(1,566)	1,175	2,064	(10,526)
Comprehensive income	$ 13,381	$ 16,071	$ 45,137	$ 30,716