Accumulated Other Comprehensive Loss (Components of AOCI) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Jan. 01, 2019	Jan. 01, 2018
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	$ (569,430)	$ (501,624)
Other comprehensive income (loss) before reclassifications	6,738	17,455
Amounts reclassified from AOCL	1,486	1,712
Other comprehensive income (loss)	8,224	19,167
Ending balance	(561,206)	(482,457)
Accumulated other comprehensive gain (loss), accumulated net gain (loss) from net investment hedge	12,200	33,700
Foreign currency translation items
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	(447,925)	(384,779)
Other comprehensive income (loss) before reclassifications	6,945	19,449
Amounts reclassified from AOCL	0	0
Other comprehensive income (loss)	6,945	19,449
Ending balance	(440,980)	(365,330)
Pension and other post-retirement effects
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	(120,647)	(115,755)
Other comprehensive income (loss) before reclassifications	(269)	(2,022)
Amounts reclassified from AOCL	1,486	1,712
Other comprehensive income (loss)	1,217	(310)
Ending balance	(119,430)	(116,065)
Cash flow hedging activity
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	(858)	(1,090)
Other comprehensive income (loss) before reclassifications	62	28
Amounts reclassified from AOCL	0	0
Other comprehensive income (loss)	62	28
Ending balance	(796)	(1,062)
Noncontrolling Interests
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Other comprehensive income (loss)	677	805
Accumulated other comprehensive income (loss), foreign currency translation adjustment, net of tax	$ 5,200	$ 4,700	$ 4,500	$ 3,800