CONDENSED CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY (UNAUDITED) - USD ($) $ in Thousands	Total	Common Stock	Treasury Stock	Additional Paid-in Capital	(Accumulated Deficit) Retained Earnings	Accumulated Other Comprehensive Income (Loss)
Impact to Retained Earnings from adoption of ASU 2016-02 | ASU 2016-02	$ 9,153				$ 9,153
Balance	598,856	$ 356	$ (6,030)	$ 639,381	(32,334)	$ (2,517)
Balance at Dec. 31, 2018	589,703	356	(6,030)	639,381	(41,487)	(2,517)
Net income	19,198				19,198
Foreign currency translation	(274)					(274)
Stock-based compensation expense	3,183			3,183
Stock options exercised	934	1		933
Balance at Mar. 31, 2019	621,897	357	(6,030)	643,497	(13,136)	(2,791)
Balance at Dec. 31, 2019	726,283	360	(6,030)	666,585	68,109	(2,741)
Net income	28,954				28,954
Foreign currency translation	(988)					(988)
Stock-based compensation expense	5,445			5,445
Stock options exercised	1,343	1		1,342
Repurchases of common stock	(43,238)	(6)			(43,232)
Balance at Mar. 31, 2020	$ 717,799	$ 355	$ (6,030)	$ 673,372	$ 53,831	$ (3,729)