Unaudited Condensed Consolidated Statements of Shareholders' Equity - USD ($) shares in Thousands, $ in Thousands	Total	Common Shares	Additional Paid-in Capital	Retained Earnings	Accumulated Other Comprehensive Loss
Beginning balance (in shares) at Dec. 31, 2017		29,953
Beginning balance at Dec. 31, 2017	$ 477,174	$ 8,984	$ 352,500	$ 135,486	$ (19,796)
Adoption of new accounting principle	6,780			6,780
Net loss	(12,264)
Foreign currency translation adjustment, net of tax	(2)				(2)
Foreign currency hedge, net of tax	(315)				(315)
Non-cash compensation	2,420		2,420
Vesting of stock awards (in shares)		34
Vesting of stock awards	(225)	$ 10	(235)
Ending balance (in shares) at Mar. 31, 2018		29,987
Ending Balance at Mar. 31, 2018	473,568	$ 8,994	354,685	130,002	(20,113)
Beginning balance (in shares) at Dec. 31, 2018		30,184
Beginning balance at Dec. 31, 2018	457,100	$ 9,053	400,989	81,450	(34,392)
Adoption of new accounting principle	(767)			(767)
Net loss	(24,228)			(24,228)
Foreign currency translation adjustment, net of tax	1,809				1,809
Foreign currency hedge, net of tax	210				210
Non-cash compensation	2,434		2,434
Vesting of stock awards (in shares)		63
Vesting of stock awards	(341)	$ 19	(360)
Ending balance (in shares) at Mar. 31, 2019		30,247
Ending Balance at Mar. 31, 2019	$ 436,217	$ 9,072	$ 403,063	$ 56,455	$ (32,373)