CONDENSED CONSOLIDATED STATEMENTS OF EQUITY - 3 months ended Mar. 31, 2018 - USD ($) $ in Thousands	Total	Additional Paid-In Capital [Member]	Accumulated Deficit [Member]	Accumulated Other Comprehensive Income [Member]	Noncontrolling Interest [Member]	Preferred Class A [Member] Series A Convertible Preferred Stock [Member]	Common Class A [Member] Common Stock [Member]	Common Class B [Member]	Common Class B [Member] Common Stock [Member]	Warrant [Member] Common Stock [Member]
BALANCE at Dec. 31, 2017	$ (5,770)	$ 1,905,779	$ (1,735,768)	$ (187,438)	$ 18	$ 0	$ 11,639		$ 0
BALANCE (in shares) at Dec. 31, 2017						1
BALANCE (in shares) at Dec. 31, 2017							145,486,497	0	0
Stockholders' Equity Attributable to Noncontrolling Interest [Roll Forward]
Stock-based compensation	1,112	1,112
Number of warrants exercised (in shares)										2,280,936
Stock and Warrants Issued During Period, Value, Preferred Stock and Warrants										$ 182
Exercise of warrants (Note 14)	2,281	2,099
Shares issuance, stock-based compensation (in shares)							467,995
Share issuance, stock-based compensation	0	(37)					$ 37
Payments of withholding tax on net share settlement of share-based compensation	(537)	(537)
Preferred dividend paid in kind	(2,447)	(2,447)
Net income / (loss)	7,072		7,250		(178)
Unrealized gain on derivative instruments (Note 12)	191			(191)
Currency translation adjustment	11,785			11,993	(208)
Currency translation adjustment	11,785
BALANCE at Mar. 31, 2018	$ 13,687	$ 1,905,969	$ (1,728,518)	$ (175,254)	$ (368)	$ 0	$ 11,858		$ 0
BALANCE (in shares) at Mar. 31, 2018						1
BALANCE (in shares) at Mar. 31, 2018							148,235,428	0	0