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)	(222,154)					(222,154)
Change in unrecognized gains/losses on derivative instruments, net of tax	(25,316)		(25,316)
Change in defined benefit plans, net of taxes	171			171
Net foreign currency translation adjustment	(9,706)				(9,706)
Common stock issued, net of shares withheld for employee taxes (in shares)		463,772
Stock-based compensation	727	$ 727
Redeemable preferred 9% dividend and accretion	(23,811)					(23,811)
European non-controlling redeemable equity dividend	(152)					(152)
End of period at Sep. 30, 2020	(28,551)	$ 94,058	(15,365)	(5,400)	(114,164)	12,320
End of the period (in shares) at Sep. 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 Jun. 30, 2020	$ (53,176)	$ 93,541	(20,048)	(5,457)	(130,548)	9,336
Beginning of the period (in shares) at Jun. 30, 2020		25,591,930
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	11,146					11,146
Change in unrecognized gains/losses on derivative instruments, net of tax	4,683		4,683
Change in defined benefit plans, net of taxes	57			57
Net foreign currency translation adjustment	16,384				16,384
Stock-based compensation	517	$ 517
Redeemable preferred 9% dividend and accretion	(8,056)					(8,056)
European non-controlling redeemable equity dividend	(106)					(106)
End of period at Sep. 30, 2020	(28,551)	$ 94,058	(15,365)	(5,400)	(114,164)	12,320
End of the period (in shares) at Sep. 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)	$ 7,637					7,637
Change in unrecognized gains/losses on derivative instruments, net of tax	101		101
Change in defined benefit plans, net of taxes	290			290
Net foreign currency translation adjustment	(16,336)				(16,336)
Common stock issued, net of shares withheld for employee taxes (in shares)		556,867
Stock-based compensation	5,371	$ 5,371
Redeemable preferred 9% dividend and accretion	(25,310)					(25,310)
European non-controlling redeemable equity dividend	(134)					(134)
End of period at Sep. 30, 2021	$ (49,903)	$ 100,618	(1,637)	(7,157)	(106,597)	(35,130)
End of the period (in shares) at Sep. 30, 2021	26,148,797	26,148,797
Beginning of period at Jun. 30, 2021	$ (20,555)	$ 98,236	5,247	(7,253)	(97,529)	(19,256)
Beginning of the period (in shares) at Jun. 30, 2021		26,107,462
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	(7,180)					(7,180)
Change in unrecognized gains/losses on derivative instruments, net of tax	(6,884)		(6,884)
Change in defined benefit plans, net of taxes	96			96
Net foreign currency translation adjustment	(9,068)				(9,068)
Common stock issued, net of shares withheld for employee taxes (in shares)		41,335
Stock-based compensation	2,382	$ 2,382
Redeemable preferred 9% dividend and accretion	(8,598)					(8,598)
European non-controlling redeemable equity dividend	(96)					(96)
End of period at Sep. 30, 2021	$ (49,903)	$ 100,618	$ (1,637)	$ (7,157)	$ (106,597)	$ (35,130)
End of the period (in shares) at Sep. 30, 2021	26,148,797	26,148,797