CONSOLIDATED STATEMENT OF SHAREHOLDERS' EQUITY - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Accumulated Deficit	Treasury Stock	Comprehensive Income (Loss)	Noncontrolling interest
Balance at Dec. 31, 2017	$ 294,874	$ 142	$ 1,087,582	$ (708,354)	$ (85,085)		$ 589
Balance (in shares) at Dec. 31, 2017		14,218,000			2,239,000
Increase (Decrease) in Stockholders' Equity
Net (loss) income and comprehensive (loss) income	31,524			31,524		$ 31,524
Non-cash compensation	$ 11,109		11,109
Purchase of treasury stock (in shares)	30,416				30,000
Purchase of treasury stock	$ (11,000)				$ (11,000)
Issuance of common stock for stock options, restricted stock awards and restricted stock units, net of withholding taxes	2,057	$ 5	2,052
Issuance of common stock for stock options, restricted stock awards and restricted stock units, net of withholding taxes (in shares)		473,000
Cumulative effect adjustment due to ASU 2014-09	1,373			1,373
Noncontrolling interest	(34)						(34)
Balance at Mar. 31, 2018	329,903	$ 147	1,100,743	(675,457)	$ (96,085)		$ 555
Balance (in shares) at Mar. 31, 2018		14,691,000			2,269,000
Balance at Dec. 31, 2018	346,208	$ 154	1,134,227	(610,482)	$ (177,691)
Balance (in shares) at Dec. 31, 2018		15,428,000			2,618,000
Increase (Decrease) in Stockholders' Equity
Net (loss) income and comprehensive (loss) income	(512)			(512)		$ (512)
Non-cash compensation	$ 14,053		14,053
Purchase of treasury stock (in shares)	17,501				18,000
Purchase of treasury stock	$ (3,976)				$ (3,976)
Issuance of common stock for stock options, restricted stock awards and restricted stock units, net of withholding taxes	(3,585)	$ 1	(3,586)
Issuance of common stock for stock options, restricted stock awards and restricted stock units, net of withholding taxes (in shares)		87,000
Balance at Mar. 31, 2019	$ 352,188	$ 155	$ 1,144,694	$ (610,994)	$ (181,667)
Balance (in shares) at Mar. 31, 2019		15,515,000			2,636,000