Condensed Consolidated Statements of Shareholders' Equity (Deficit) - USD ($) $ in Thousands	Total	Common Stock	Unrecognized Gains (Losses) on Derivative Instruments	Pension Obligations	Cumulative Translation Adjustment	Retained Earnings
Beginning of period at Dec. 31, 2019	$ 251,690	$ 93,331	$ 9,951	$ (5,571)	$ (104,458)	$ 258,437
Beginning of the period (in shares) at Dec. 31, 2019		25,128,158
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	(190,082)					(190,082)
Change in unrecognized gains/losses on derivative instruments, net of tax	(45,297)		(45,297)
Change in defined benefit plans, net of taxes	55			55
Net foreign currency translation adjustment	(35,533)				(35,533)
Common stock issued, net of shares withheld for employee taxes (in shares)		346,319
Stock-based compensation	(653)	$ (653)
Redeemable preferred 9% dividend and accretion	(7,850)					(7,850)
European non-controlling redeemable equity dividend	(20)					(20)
End of period at Mar. 31, 2020	(27,690)	$ 92,678	(35,346)	(5,516)	(139,991)	60,485
End of the period (in shares) at Mar. 31, 2020		25,474,477
Beginning of period at Dec. 31, 2019	251,690	$ 93,331	9,951	(5,571)	(104,458)	258,437
Beginning of the period (in shares) at Dec. 31, 2019		25,128,158
End of period at Dec. 31, 2020	$ (21,522)	$ 95,247	(1,738)	(7,447)	(90,261)	(17,323)
End of the period (in shares) at Dec. 31, 2020	25,591,930	25,591,930
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	$ 13,122					13,122
Change in unrecognized gains/losses on derivative instruments, net of tax	(8,462)		(8,462)
Change in defined benefit plans, net of taxes	76			76
Net foreign currency translation adjustment	(15,678)				(15,678)
Common stock issued, net of shares withheld for employee taxes (in shares)		355,532
Stock-based compensation	505	$ 505
Redeemable preferred 9% dividend and accretion	(8,290)					(8,290)
European non-controlling redeemable equity dividend	(13)					(13)
End of period at Mar. 31, 2021	$ (40,262)	$ 95,752	$ (10,200)	$ (7,371)	$ (105,939)	$ (12,504)
End of the period (in shares) at Mar. 31, 2021	25,947,462	25,947,462