CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Statement of Comprehensive Income [Abstract]
Net income	$ 39,390	$ 28,004	$ 32,032
Other comprehensive income:
Unrealized gain (loss) on available-for-sale securities, net of tax	(3)	(26)	13
Comprehensive income	$ 39,387	$ 27,978	$ 32,045