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)	(233,300)					(233,300)
Change in unrecognized gains/losses on derivative instruments, net of tax	(29,999)		(29,999)
Change in defined benefit plans, net of taxes	114			114
Net foreign currency translation adjustment	(26,090)				(26,090)
Common stock issued, net of shares withheld for employee taxes (in shares)		463,772
Stock-based compensation	210	$ 210
Redeemable preferred 9% dividend and accretion	(15,755)					(15,755)
European non-controlling redeemable equity dividend	(46)					(46)
End of period at Jun. 30, 2020	(53,176)	$ 93,541	(20,048)	(5,457)	(130,548)	9,336
End of the period (in shares) at Jun. 30, 2020		25,591,930
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
Beginning of period at Mar. 31, 2020	$ (27,690)	$ 92,678	(35,346)	(5,516)	(139,991)	60,485
Beginning of the period (in shares) at Mar. 31, 2020		25,474,477
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	(43,218)					(43,218)
Change in unrecognized gains/losses on derivative instruments, net of tax	15,298		15,298
Change in defined benefit plans, net of taxes	59			59
Net foreign currency translation adjustment	9,443				9,443
Common stock issued, net of shares withheld for employee taxes (in shares)		117,453
Stock-based compensation	863	$ 863
Redeemable preferred 9% dividend and accretion	(7,905)					(7,905)
European non-controlling redeemable equity dividend	(26)					(26)
End of period at Jun. 30, 2020	(53,176)	$ 93,541	(20,048)	(5,457)	(130,548)	9,336
End of the period (in shares) at Jun. 30, 2020		25,591,930
Beginning of period at Dec. 31, 2020	$ (21,522)	$ 95,247	(1,738)	(7,447)	(90,261)	(17,323)
Beginning 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)	$ 14,817					14,817
Change in unrecognized gains/losses on derivative instruments, net of tax	6,985		6,985
Change in defined benefit plans, net of taxes	194			194
Net foreign currency translation adjustment	(7,268)				(7,268)
Common stock issued, net of shares withheld for employee taxes (in shares)		515,532
Stock-based compensation	2,989	$ 2,989
Redeemable preferred 9% dividend and accretion	(16,712)					(16,712)
European non-controlling redeemable equity dividend	(38)					(38)
End of period at Jun. 30, 2021	$ (20,555)	$ 98,236	5,247	(7,253)	(97,529)	(19,256)
End of the period (in shares) at Jun. 30, 2021	26,107,462	26,107,462
Beginning of period at Mar. 31, 2021	$ (40,262)	$ 95,752	(10,200)	(7,371)	(105,939)	(12,504)
Beginning of the period (in shares) at Mar. 31, 2021		25,947,462
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	1,695					1,695
Change in unrecognized gains/losses on derivative instruments, net of tax	15,447		15,447
Change in defined benefit plans, net of taxes	118			118
Net foreign currency translation adjustment	8,410				8,410
Common stock issued, net of shares withheld for employee taxes (in shares)		160,000
Stock-based compensation	2,484	$ 2,484
Redeemable preferred 9% dividend and accretion	(8,422)					(8,422)
European non-controlling redeemable equity dividend	(25)					(25)
End of period at Jun. 30, 2021	$ (20,555)	$ 98,236	$ 5,247	$ (7,253)	$ (97,529)	$ (19,256)
End of the period (in shares) at Jun. 30, 2021	26,107,462	26,107,462