Accumulated Other Comprehensive Income (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance		$ 860,716	$ 897,482	$ 881,589	$ 859,947
Other comprehensive (loss) income before reclassifications		18,527	(17,771)	(16,159)	(15,414)
Amounts reclassified from OCI		(205)	4	(7,235)	(341)
Ending balance		896,785	896,673	896,785	896,673
Accumulated Other Comprehensive (Loss) Income [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance		(204,724)	(163,543)	(163,008)	(165,555)
Ending balance		(186,402)	(181,310)	(186,402)	(181,310)
Cash Flow Hedges [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	[1]	(912)	(58)	(199)	147
Other comprehensive (loss) income before reclassifications	[1]	889	(91)	(995)	(25)
Amounts reclassified from OCI	[1]	209	42	1,380	(229)
Ending balance	[1]	186	(107)	186	(107)
Pension Items [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	[1]	(656)	475	(672)	549
Other comprehensive (loss) income before reclassifications	[1]	0	0	0	0
Amounts reclassified from OCI	[1]	8	(38)	24	(112)
Ending balance	[1]	(648)	437	(648)	437
Foreign Currency Items [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance		(203,156)	(163,960)	(162,137)	(166,251)
Other comprehensive (loss) income before reclassifications		17,638	(17,680)	(15,164)	(15,389)
Amounts reclassified from OCI		(422)	0	(8,639)	0
Ending balance		$ (185,940)	$ (181,640)	$ (185,940)	$ (181,640)

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