Consolidated Statements of Equity - USD ($) $ in Thousands	Total	Common Stock	Treasury Stock	Additional Paid-in Capital	Accumulated Other Comprehensive Income (Loss)	Retained Earnings (Accumulated Deficit)	Non-controlling Interests
Beginning balance (in shares) at Dec. 31, 2016		59,685,000	2,029,000
Beginning balance at Dec. 31, 2016	$ 287,701	$ 6	$ (20,269)	$ 318,392	$ (956)	$ (9,830)	$ 358
Increase (Decrease) in Stockholders' Equity
Net loss	(27,395)					(27,395)
Foreign currency translation adjustment	72
Stock issued under employee stock purchase plan (in shares)			(113,000)
Stock issued under employee stock purchase plan	654			654
Common stock issued in payment of accrued liability (in shares)		0
Common stock issued in payment of accrued liability	188			188
Stock options exercised (in shares)		663,000
Stock options exercised	$ 5,884	$ 0		5,884
Restricted stock awards granted (in shares)		275,000
Restricted stock awards forfeited (in shares)			122,000
Treasury stock purchased (in shares)	238,216		200,000
Treasury stock purchased	$ (1,729)		$ (1,729)
Stock surrendered for exercise of stock options (in shares)	3,225		478,000
Stock surrendered for exercise of stock options	$ (5,863)		$ (5,863)
Stock compensation expense	10,949			10,949
Repurchase of common stock (in shares)			905,000
Repurchase of common stock	5,203		$ 5,203
Ending balance (in shares) at Dec. 31, 2017		60,623,000	3,621,000
Ending balance at Dec. 31, 2017	265,258	$ 6	$ (33,064)	336,067	(884)	(37,225)	358
Increase (Decrease) in Stockholders' Equity
Net loss	(70,698)					(70,340)	(358)
Foreign currency translation adjustment	(232)
Stock issued under employee stock purchase plan (in shares)			(111,000)
Stock issued under employee stock purchase plan	341			341
Common stock issued in payment of accrued liability	$ 0
Restricted stock awards granted (in shares)	1,539,889	1,540,000
Restricted stock awards forfeited (in shares)			158,000
Treasury stock purchased (in shares)	199,644		102,000
Treasury stock purchased	$ (173)		$ (173)
Stock surrendered for exercise of stock options (in shares)	478,287
Stock compensation expense	$ 7,128			7,128
Repurchase of common stock (in shares)	0
Ending balance (in shares) at Dec. 31, 2018		62,163,000	3,770,000
Ending balance at Dec. 31, 2018	$ 201,624	$ 6	$ (33,237)	343,536	(1,116)	(107,565)	0
Increase (Decrease) in Stockholders' Equity
Net loss	(32,279)					(32,279)
Foreign currency translation adjustment	150				150
Stock issued under employee stock purchase plan (in shares)			(18,000)
Stock issued under employee stock purchase plan	35			35
Common stock issued in payment of accrued liability	$ 0
Stock options exercised (in shares)	0
Restricted stock awards granted (in shares)	924,022	924,000
Restricted stock awards forfeited (in shares)			299,000
Treasury stock purchased (in shares)	93,977		94,000
Treasury stock purchased	$ (247)		$ (247)
Stock surrendered for exercise of stock options (in shares)	0
Stock compensation expense	$ 3,993			3,993
Ending balance (in shares) at Dec. 31, 2019		63,657,000	4,145,000
Ending balance at Dec. 31, 2019	$ 173,276	$ 6	$ (33,484)	$ 347,564	$ (966)	$ (139,844)	$ 0