Accumulated Other Comprehensive Income (Loss) - Changes in Components (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Accumulated Other Comprehensive Income (Loss)
Balance	$ 393,991	$ 405,473	$ 416,505
Total other comprehensive loss	(11,969)	(14,120)	(26,370)
Balance	381,143	393,991	405,473
Accumulated Other Comprehensive Income (Loss)
Accumulated Other Comprehensive Income (Loss)
Balance	(41,630)	(27,510)	(1,140)
Other comprehensive income (loss) before reclassifications	(15,026)	(15,658)	(26,730)
Amounts reclassified from other comprehensive income (loss)	3,057	1,538	360
Total other comprehensive loss	(11,969)	(14,120)	(26,370)
Balance	(53,599)	(41,630)	(27,510)
Foreign Currency Translation Adjustments
Accumulated Other Comprehensive Income (Loss)
Balance	(11,070)	1,943	16,793
Other comprehensive income (loss) before reclassifications	(10,956)	(13,013)	(14,850)
Total other comprehensive loss	(10,956)	(13,013)	(14,850)
Balance	(22,026)	(11,070)	1,943
Defined Benefit Pension Plan Adjustments
Accumulated Other Comprehensive Income (Loss)
Balance	(30,474)	(30,358)	(18,450)
Other comprehensive income (loss) before reclassifications	(4,879)	(2,446)	(12,669)
Amounts reclassified from other comprehensive income (loss)	2,980	2,330	761
Total other comprehensive loss	(1,899)	(116)	(11,908)
Balance	(32,373)	(30,474)	(30,358)
Derivatives
Accumulated Other Comprehensive Income (Loss)
Balance	(86)	905	517
Other comprehensive income (loss) before reclassifications	809	(199)	789
Amounts reclassified from other comprehensive income (loss)	77	(792)	(401)
Total other comprehensive loss	886	(991)	388
Balance	$ 800	$ (86)	$ 905