CONDENSED CONSOLIDATED STATEMENTS OF EQUITY - 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]
BALANCE at Dec. 31, 2018	$ 229,321	$ 2,003,518	$ (1,578,076)	$ (216,650)	$ 301	$ 0	$ 20,228		$ 0
BALANCE (in shares) at Dec. 31, 2018						1
BALANCE (in shares) at Dec. 31, 2018							252,853,554		0
Stockholders' Equity Attributable to Noncontrolling Interest [Roll Forward]
Stock-based compensation	1,003	1,003
Shares issuance, stock-based compensation (in shares)							426,421
Share issuance, stock-based compensation	0	(34)					$ (34)
Share-based Payment Arrangement, Decrease for Tax Withholding Obligation	(299)	(299)
Net income / (loss)	11,751		11,758		(7)
Unrealized gain / (loss) on derivative instruments (Note 13)	(3,331)			(3,331)
Currency translation adjustment	(15,843)			(15,980)	137
Currency translation adjustment	(15,843)
BALANCE at Mar. 31, 2019	222,602	2,004,188	(1,566,318)	(235,961)	431	$ 0	$ 20,262		$ 0
BALANCE (in shares) at Mar. 31, 2019						1
BALANCE (in shares) at Mar. 31, 2019							253,279,975		0
BALANCE at Dec. 31, 2019	342,218	2,007,275	(1,458,942)	(226,916)	513	$ 0	$ 20,288		$ 0
BALANCE (in shares) at Dec. 31, 2019						1
BALANCE (in shares) at Dec. 31, 2019							253,607,026	0	0
Stockholders' Equity Attributable to Noncontrolling Interest [Roll Forward]
Stock-based compensation	939	939
Shares issuance, stock-based compensation (in shares)							691,229
Share issuance, stock-based compensation	0	(55)					$ (55)
Share-based Payment Arrangement, Decrease for Tax Withholding Obligation	(8)	(8)
Net income / (loss)	8,970		9,041		(71)
Unrealized gain / (loss) on derivative instruments (Note 13)	220			220
Currency translation adjustment	(61,049)			(61,223)	174
Currency translation adjustment	(61,049)
BALANCE at Mar. 31, 2020	$ 291,290	$ 2,008,151	$ (1,449,901)	$ (287,919)	$ 616	$ 0	$ 20,343		$ 0
BALANCE (in shares) at Mar. 31, 2020						1
BALANCE (in shares) at Mar. 31, 2020							254,298,255	0	0