Shareholders' Equity Accumulated Other Comprehensive Income (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	$ 800,815	$ 734,048
OCI before reclassifications	(24,629)	(1,848)
Amounts reclassified from AOCI	(582)	68
Total other comprehensive income (loss), net of tax	(25,211)	(1,780)
Ending balance	795,495	732,031
Parent [Member]
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	776,538	712,663
Total other comprehensive income (loss), net of tax	(25,211)	(1,780)
Ending balance	770,740	709,405
Foreign Currency Translation Adjustments
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	(157,999)	(157,489)
OCI before reclassifications	(25,445)	(2,386)
Amounts reclassified from AOCI	0	0
Total other comprehensive income (loss), net of tax	(25,445)	(2,386)
Ending balance	(183,444)	(159,875)
Net Unrealized Gain (Loss) on Derivative Instruments
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	(723)	1,201
OCI before reclassifications	282	211
Amounts reclassified from AOCI	(1,049)	(76)
Total other comprehensive income (loss), net of tax	(767)	135
Ending balance	(1,490)	1,336
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)
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)
Pension Benefit Obligation Adjustments
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	(31,570)	(25,637)
OCI before reclassifications	534	327
Amounts reclassified from AOCI	467	144
Total other comprehensive income (loss), net of tax	1,001	471
Ending balance	(30,569)	(25,166)
Accumulated Other Comprehensive Income (Loss)
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	(204,672)	(196,305)
Ending balance	$ (229,883)	$ (198,085)