Condensed Consolidated Statements of Shareholders' Equity - USD ($) $ in Thousands	Total	Common Stock	Unrecognized Gains (Losses) on Derivative Instruments	Pension Obligations	Cumulative Translation Adjustment	Retained Earnings	Non-controlling Interest
Beginning of period at Dec. 31, 2017	$ 445,723	$ 89,755	$ (8,498)	$ (5,257)	$ (75,366)	$ 393,146	$ 51,943
Beginning of the period (in shares) at Dec. 31, 2017		24,917,025
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	18,452					18,452
Change in unrecognized gains (losses) on derivative instruments, net of tax	(4,079)		(4,079)
Change in employee benefit plans, net of taxes	131			131
Net foreign currency translation adjustment	(14,329)				(14,329)
Stock options exercised	68	$ 68
Stock options exercised (in shares)		4,500
Common stock issued, net of shares withheld for employee taxes (in shares)		90,205
Stock-based compensation	1,107	$ 1,107
Cash dividends declared	(4,845)					(4,845)
Redeemable preferred dividend and accretion	(16,204)					(16,204)
Reclassification to European non-controlling redeemable equity	(51,943)						(51,943)
Adjust European non-controlling redeemable equity to redemption value	(3,625)	(3,625)
European non-controlling redeemable equity dividend	(1,084)					(1,084)
End of period at Jun. 30, 2018	369,372	$ 87,305	(12,577)	(5,126)	(89,695)	389,465
End of the period (in shares) at Jun. 30, 2018		25,011,730
Beginning of period at Dec. 31, 2017	445,723	$ 89,755	(8,498)	(5,257)	(75,366)	393,146	$ 51,943
Beginning of the period (in shares) at Dec. 31, 2017		24,917,025
End of period at Dec. 31, 2018	$ 373,265	$ 87,723	(3,205)	(3,000)	(99,290)	391,037
End of the period (in shares) at Dec. 31, 2018	25,019,237	25,019,237
Beginning of period at Mar. 31, 2018	$ 424,280	$ 86,259	5,412	(5,170)	(54,462)	392,241
Beginning of the period (in shares) at Mar. 31, 2018		24,984,791
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	8,135					8,135
Change in unrecognized gains (losses) on derivative instruments, net of tax	(17,989)		(17,989)
Change in employee benefit plans, net of taxes	44			44
Net foreign currency translation adjustment	(35,233)				(35,233)
Stock options exercised	68	$ 68
Stock options exercised (in shares)		4,500
Common stock issued, net of shares withheld for employee taxes (in shares)		22,439
Stock-based compensation	978	$ 978
Cash dividends declared	(2,265)					(2,265)
Redeemable preferred dividend and accretion	(8,135)					(8,135)
European non-controlling redeemable equity dividend	(511)					(511)
End of period at Jun. 30, 2018	369,372	$ 87,305	(12,577)	(5,126)	(89,695)	389,465
End of the period (in shares) at Jun. 30, 2018		25,011,730
Beginning of period at Dec. 31, 2018	$ 373,265	$ 87,723	(3,205)	(3,000)	(99,290)	391,037
Beginning of the period (in shares) at Dec. 31, 2018	25,019,237	25,019,237
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	$ 9,220					9,220
Change in unrecognized gains (losses) on derivative instruments, net of tax	6,782		6,782
Change in employee benefit plans, net of taxes	83			83
Net foreign currency translation adjustment	684				684
Common stock issued, net of shares withheld for employee taxes (in shares)		95,361
Stock-based compensation	1,809	$ 1,809
Cash dividends declared	(4,582)					(4,582)
Redeemable preferred dividend and accretion	(15,688)					(15,688)
European non-controlling redeemable equity dividend	(383)					(383)
End of period at Jun. 30, 2019	$ 371,190	$ 89,532	3,577	(2,917)	(98,606)	379,604
End of the period (in shares) at Jun. 30, 2019	25,114,598	25,114,598
Beginning of period at Mar. 31, 2019	$ 363,014	$ 88,119	1,721	(2,959)	(106,639)	382,772
Beginning of the period (in shares) at Mar. 31, 2019		25,073,360
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	7,270					7,270
Change in unrecognized gains (losses) on derivative instruments, net of tax	1,856		1,856
Change in employee benefit plans, net of taxes	42			42
Net foreign currency translation adjustment	8,033				8,033
Common stock issued, net of shares withheld for employee taxes (in shares)		41,238
Stock-based compensation	1,413	$ 1,413
Cash dividends declared	(2,259)					(2,259)
Redeemable preferred dividend and accretion	(7,917)					(7,917)
European non-controlling redeemable equity dividend	(262)					(262)
End of period at Jun. 30, 2019	$ 371,190	$ 89,532	$ 3,577	$ (2,917)	$ (98,606)	$ 379,604
End of the period (in shares) at Jun. 30, 2019	25,114,598	25,114,598