Unaudited Condensed Consolidated Statements of Stockholders' 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, 2017		(60,623,000)	3,621,000
Beginning balance at Dec. 31, 2017	$ 265,258	$ 6	$ (33,064)	$ 336,067	$ (884)	$ (37,225)	$ 358
Increase (Decrease) in Equity [Roll Forward]
Net income (loss)	(79,256)					(78,899)	(357)
Foreign currency translation adjustment	(76)				(76)
Stock issued under employee stock purchase plan (in shares)			(111,000)
Stock issued under employee stock purchase plan	341			341
Restricted stock granted (in shares)		1,480,000
Restricted stock forfeited (in shares)			45,000
Treasury stock purchased (in shares)			29,000
Treasury stock purchased	(91)		$ (91)
Stock compensation expense	6,640			6,640
Ending balance (in shares) at Sep. 30, 2018		(62,103,000)	3,584,000
Ending balance at Sep. 30, 2018	192,816	$ 6	$ (33,155)	343,048	(960)	(116,124)	1
Beginning balance (in shares) at Jun. 30, 2018		(61,642,000)	(3,607,000)
Beginning balance at Jun. 30, 2018	194,300	$ 6	$ (33,088)	340,618	(1,045)	(112,192)	1
Increase (Decrease) in Equity [Roll Forward]
Net income (loss)	(3,932)					(3,932)	0
Foreign currency translation adjustment	85				85
Stock issued under employee stock purchase plan (in shares)			(46,000)
Stock issued under employee stock purchase plan	94			94
Restricted stock granted (in shares)		461,000
Restricted stock forfeited (in shares)			0
Treasury stock purchased (in shares)			23,000
Treasury stock purchased	(67)		$ (67)
Stock compensation expense	2,336			2,336
Ending balance (in shares) at Sep. 30, 2018		(62,103,000)	3,584,000
Ending balance at Sep. 30, 2018	192,816	$ 6	$ (33,155)	343,048	(960)	(116,124)	1
Beginning balance (in shares) at Dec. 31, 2018		(62,163,000)	3,770,000
Beginning balance at Dec. 31, 2018	201,624	$ 6	$ (33,237)	343,536	(1,116)	(107,565)	0
Increase (Decrease) in Equity [Roll Forward]
Net income (loss)	7,284					7,284
Foreign currency translation adjustment	154				154
Stock issued under employee stock purchase plan (in shares)			(7,000)
Stock issued under employee stock purchase plan	$ 15			15
Restricted stock granted (in shares)	875,522	875,000
Restricted stock forfeited (in shares)			292,000
Treasury stock purchased (in shares)			74,000
Treasury stock purchased	$ (207)		$ (207)
Stock compensation expense	2,841			2,841
Ending balance (in shares) at Sep. 30, 2019		(63,038,000)	4,129,000
Ending balance at Sep. 30, 2019	211,711	$ 6	$ (33,444)	346,392	(962)	(100,281)	0
Beginning balance (in shares) at Jun. 30, 2019		(62,956,000)	3,948,000
Beginning balance at Jun. 30, 2019	221,676	$ 6	$ (33,378)	345,217	(998)	(89,171)	0
Increase (Decrease) in Equity [Roll Forward]
Net income (loss)	(11,110)					(11,110)
Foreign currency translation adjustment	36				36
Stock issued under employee stock purchase plan (in shares)			(8,000)
Stock issued under employee stock purchase plan	15			15
Restricted stock granted (in shares)		82,000
Restricted stock forfeited (in shares)			159,000
Treasury stock purchased (in shares)			30,000
Treasury stock purchased	(66)		$ (66)
Stock compensation expense	1,160			1,160
Ending balance (in shares) at Sep. 30, 2019		(63,038,000)	4,129,000
Ending balance at Sep. 30, 2019	$ 211,711	$ 6	$ (33,444)	$ 346,392	$ (962)	$ (100,281)	$ 0