Shareholders' Equity Accumulated Other Comprehensive Income (Details) - USD ($) $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2019	Mar. 31, 2019	Jun. 30, 2020	Jun. 30, 2019
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	$ 795,495	$ 800,815	$ 732,031	$ 734,048	$ 800,815	$ 734,048
OCI before reclassifications					(15,966)	4,462
Amounts reclassified from AOCI					52,811	(2,506)
Total other comprehensive income (loss), net of tax	62,056	(25,211)	3,736	(1,780)	36,845	1,956
Ending balance	802,869	795,495	746,599	732,031	802,869	746,599
Parent [Member]
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	770,740	776,538	709,405	712,663	776,538	712,663
Total other comprehensive income (loss), net of tax	62,056	(25,211)	3,736	(1,780)
Ending balance	777,799	770,740	723,302	709,405	777,799	723,302
Foreign Currency Translation Adjustments
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance		(157,999)		(157,489)	(157,999)	(157,489)
OCI before reclassifications					(14,135)	2,801
Amounts reclassified from AOCI					52,088	0
Total other comprehensive income (loss), net of tax					37,953	2,801
Ending balance	(120,046)		(154,688)		(120,046)	(154,688)
Net Unrealized Gain (Loss) on Derivative Instruments
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance		(723)		1,201	(723)	1,201
OCI before reclassifications					(1,914)	998
Amounts reclassified from AOCI					(242)	(2,497)
Total other comprehensive income (loss), net of tax					(2,156)	(1,499)
Ending balance	(2,879)		(298)		(2,879)	(298)
Net Unrealized Gain (Loss) on Nonderivative Instruments
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance		(14,380)		(14,380)	(14,380)	(14,380)
OCI before reclassifications					0	0
Amounts reclassified from AOCI					0	0
Total other comprehensive income (loss), net of tax					0	0
Ending balance	(14,380)		(14,380)		(14,380)	(14,380)
Pension Benefit Obligation Adjustments
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance		(31,570)		(25,637)	(31,570)	(25,637)
OCI before reclassifications					83	663
Amounts reclassified from AOCI					965	(9)
Total other comprehensive income (loss), net of tax					1,048	654
Ending balance	(30,522)		(24,983)		(30,522)	(24,983)
Accumulated Other Comprehensive Income (Loss)
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance		$ (204,672)		$ (196,305)	(204,672)	(196,305)
Ending balance	$ (167,827)		$ (194,349)		$ (167,827)	$ (194,349)