CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Statement Of Income And Comprehensive Income [Abstract]
Net income	$ 26,143	$ 19,311	$ 7,370
Short term investments:
Unrealized (loss) gain on short term investments, net of income tax (benefit) expense of $(8), $(2) and $4, respectively	(16)	(4)	8
Reclassification adjustments, net of income tax expense of $2 in 2013	0	0	4
Other comprehensive (loss) income, net of tax	(16)	(4)	12
Comprehensive income	$ 26,127	$ 19,307	$ 7,382