Condensed Consolidated Statement of Shareholders' Equity - 9 months ended Sep. 30, 2018 - 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	24,917,025
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	$ 17,789					17,789
Change in unrecognized gains on derivative instruments, net of tax	13,444		13,444
Change in employee benefit plans, net of taxes	255			255
Net foreign currency translation adjustment	(12,898)				(12,898)
Stock options exercised	$ 68	$ 68
Stock options exercised (in shares)	4,500	4,500
Restricted stock awards granted, net of forfeitures	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0
Restricted stock awards granted, net of forfeitures (in shares)		97,712
Stock-based compensation expense	$ 2,355	$ 2,355
Stock-based compensation expense (in shares)	0	0	0	0	0	0	0
Cash dividends declared ($0.27 per share)	$ (7,101)					$ (7,101)
Redeemable preferred dividend and accretion	(24,499)					(24,499)
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-controllingredeemable equity translation adjustment	2,882					2,882
European non-controllingredeemable equity dividend	(1,342)					(1,342)
End of period at Sep. 30, 2018	$ 381,108	$ 88,553	$ 4,946	$ (5,002)	$ (88,264)	$ 380,875
End of the period (in shares) at Sep. 30, 2018	25,019,237	25,019,237