Accumulated Other Comprehensive Income (Details) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2021	Mar. 31, 2020
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance		$ 934,336	$ 881,589
Other comprehensive loss before reclassifications		(14,903)	(44,790)
Amounts reclassified from OCI		(236)	437
Ending balance		925,646	842,658
Accumulated Other Comprehensive (Loss) Income [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance		(159,091)	(163,008)
Ending balance		(174,230)	(207,361)
Cash Flow Hedges [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	[1]	749	(199)
Other comprehensive loss before reclassifications	[1]	720	(1,865)
Amounts reclassified from OCI	[1]	(289)	429
Ending balance	[1]	1,180	(1,635)
Pension Items [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	[1]	(1,965)	(672)
Other comprehensive loss before reclassifications	[1]	0	0
Amounts reclassified from OCI	[1]	52	8
Ending balance	[1]	(1,913)	(664)
Foreign Currency Items [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance		(157,875)	(162,137)
Other comprehensive loss before reclassifications		(15,623)	(42,925)
Amounts reclassified from OCI		1	0
Ending balance		$ (173,497)	$ (205,062)

[1] Cash Flow Hedges and Pension Items are net of tax.