CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-In Capital	Retained Earnings	Accumulated Other Comprehensive Income (Loss)
Balances at Dec. 31, 2016	$ 616,570	$ 269	$ 117,192	$ 533,435	$ (34,326)
Net loss	(253,116)			(253,116)
Foreign currency translation adjustment	979				979
Reclassification of Russia cumulative translation loss to Net Loss upon sale	33,347				$ 33,347
Comprehensive loss	(218,790)
Issuance of warrant	3,870		3,870
Stock granted under restricted stock plan, net	400	2	398
Stock based compensation	4,255		4,255
Shares surrendered by employees to pay taxes	(540)			(540)
Balances at Dec. 31, 2017	405,765	271	125,715	279,779
Net loss	(75,433)			(75,433)
Comprehensive loss	(75,433)
Stock sold under ATM program	2,849	3	2,846
Stock granted under restricted stock plan, net	320	4	316
Stock based compensation	3,203		3,203
Shares surrendered by employees to pay taxes	(421)	(1)		(420)
Balances at Dec. 31, 2018	$ 336,283	$ 277	$ 132,080	$ 203,926