Condensed Consolidated Statements of Shareholders' Equity - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-In Capital	Retained Earnings	Accumulated Other Comprehensive (Loss) Income
Balance at Dec. 31, 2017	$ 174,956	$ 678		$ 186,117	$ (11,839)
Balance (in shares) at Dec. 31, 2017		67,776,138
Repurchase of common stock	(55,815)	$ (13)	$ (4,340)	(51,462)
Repurchase of common stock (in shares)		(1,269,109)
Restricted stock units issuance		$ 3	(3)
Restricted stock units issuance (in shares)		312,402
Equity-based compensation	4,343		4,343
Adjustment due to adoption of ASC 2014-09 Revenue from Contracts with Customers (Topic 606) | ASC 2014-09	1,981			1,981
Foreign currency translation adjustment	(169)				(169)
Net income	22,652			22,652
Balance at Mar. 31, 2018	147,948	$ 668		159,288	(12,008)
Balance (in shares) at Mar. 31, 2018		66,819,431
Balance at Dec. 31, 2018	147,147	$ 649		163,359	(16,861)
Balance (in shares) at Dec. 31, 2018		64,860,419
Repurchase of common stock	(30,160)	$ (6)	(7,179)	(22,975)
Repurchase of common stock (in shares)		(569,906)
Restricted stock units issuance		$ 3	(3)
Restricted stock units issuance (in shares)		303,396
Equity-based compensation	7,182		$ 7,182
Foreign currency translation adjustment	259				259
Net income	20,972			20,972
Balance at Mar. 31, 2019	$ 145,400	$ 646		$ 161,356	$ (16,602)
Balance (in shares) at Mar. 31, 2019		64,593,909