CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Statement of Comprehensive Income [Abstract]
Net income	$ 15,630	$ 14,494	$ 29,141	$ 28,126
Other comprehensive income (loss):
Change in unrealized (depreciation) appreciation of available-for-sale securities	(4,727)	2,759	(1,781)	6,775
Reclassification adjustment for realized (gains) losses included in net income	(4)	0	(4)	(963)
Income tax effect	1,776	(1,036)	670	(2,182)
Other comprehensive (loss) income, net of tax	(2,955)	1,723	(1,115)	3,630
Comprehensive income	$ 12,675	$ 16,217	$ 28,026	$ 31,756