Accumulated Other Comprehensive Income (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Jun. 30, 2019	Dec. 31, 2018	Jun. 30, 2018	Dec. 31, 2017
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated Other Comprehensive Income (Loss), Net of Tax	$ (53,403)		$ (53,403)			$ (51,247)
Other Comprehensive Income (Loss), Foreign Currency Translation Gain (Loss) Arising During Period, Tax	597	$ (1,081)	(2,526)	$ 6,992
Reclassification from Accumulated Other Comprehensive Income, Current Period, Tax	0	0	0	15,935
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, Tax	39	1	219	2
Accumulated Foreign Currency Adjustment Attributable to Parent [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated Other Comprehensive Income (Loss), Net of Tax	(39,572)	(23,319)	(39,572)	(23,319)	$ (33,148)	(45,816)	$ (26,668)	$ (51,014)
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax	(6,424)	3,349	17,128	(21,651)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax			(10,884)	49,346
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, after Tax	0	0	0	0
Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated Other Comprehensive Income (Loss), Net of Tax	(4,838)	(2,779)	(4,838)	(2,779)	(4,945)	(5,431)	(2,782)	(2,787)
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax	0	0	0	0
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax			0	0
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, after Tax	107	3	593	8
AOCI Including Portion Attributable to Noncontrolling Interest [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated Other Comprehensive Income (Loss), Net of Tax	(44,410)	(26,098)	(44,410)	(26,098)	(38,093)	(51,247)	$ (29,450)	$ (53,801)
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax	(6,424)	3,349	17,128	(21,651)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax			(10,884)	49,346
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, after Tax	107	$ 3	593	$ 8
Noncontrolling Interest [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated Other Comprehensive Income (Loss), Net of Tax	8,993		8,993		13,598	0
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax	(4,519)		9,062
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax			0
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, after Tax	(86)		(69)
AOCI Attributable to Parent [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated Other Comprehensive Income (Loss), Net of Tax	(53,403)		(53,403)		$ (51,691)	$ (51,247)
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax	(1,905)		8,066
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax			(10,884)
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, after Tax	$ 193		$ 662