Condensed Consolidated Statement of Changes in Stockholders' Equity - 3 months ended Mar. 31, 2017 - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock	Additional Paid-In Capital	Treasury Stock	Accumulated Deficit
Beginning balance (in shares) at Dec. 31, 2016		15,891
Beginning balance at Dec. 31, 2016	$ 151,226	$ 16	$ 213,872	$ (37,003)	$ (25,659)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation expense	4,193		4,193
Issuance of common stock upon exercise of stock option grants (in shares)		117
Issuance of common stock upon exercise of stock option grants	2,137		2,137
Common stock repurchases	(13,653)			(13,653)
Net income	22,924				22,924
Ending balance (in shares) at Mar. 31, 2017		16,008
Ending balance at Mar. 31, 2017	$ 166,827	$ 16	$ 220,202	$ (50,656)	$ (2,735)