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	10,317					10,317
Change in unrecognized gains (losses) on derivative instruments, net of tax	13,910		13,910
Change in employee benefit plans, net of taxes	87			87
Net foreign currency translation adjustment	20,904				20,904
Common stock issued, net of shares withheld for employee taxes	(330)					(330)
Common stock issued, net of shares withheld for employee taxes (in shares)		67,766
Stock-based compensation	129	$ 129
Cash dividends declared	(2,250)					(2,250)
Redeemable preferred dividend and accretion	(8,069)					(8,069)
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	(573)					(573)
End of period at Mar. 31, 2018	424,280	$ 86,259	5,412	(5,170)	(54,462)	392,241
End of the period (in shares) at Mar. 31, 2018		24,984,791
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
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	$ 1,950					1,950
Change in unrecognized gains (losses) on derivative instruments, net of tax	4,926		4,926
Change in employee benefit plans, net of taxes	41			41
Net foreign currency translation adjustment	(7,349)				(7,349)
Common stock issued, net of shares withheld for employee taxes (in shares)		54,123
Stock-based compensation	396	$ 396
Cash dividends declared	(2,323)					(2,323)
Redeemable preferred dividend and accretion	(7,771)					(7,771)
European non-controlling redeemable equity dividend	(121)					(121)
End of period at Mar. 31, 2019	$ 363,014	$ 88,119	$ 1,721	$ (2,959)	$ (106,639)	$ 382,772
End of the period (in shares) at Mar. 31, 2019	25,073,360	25,073,360