Accumulated Other Comprehensive Loss - Summary (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Jan. 01, 2018	Jan. 01, 2017
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	$ 2,536,568	$ 2,453,577	$ 2,057,656
Amortization	23,246	21,077	20,486
Pension lump sum settlement	27,391
Other current period change	24,506	(121,308)	102,710
Adoption of new accounting standard					$ (312,571)
Ending balance	2,476,310	2,536,568	2,453,577
Currency Translation Adjustments and Other
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(199,713)	(143,773)	(206,610)
Amortization	0	0	0
Pension lump sum settlement	0
Other current period change	30,681	(55,940)	62,837
Adoption of new accounting standard				$ 0
Ending balance	(169,032)	(199,713)	(143,773)
Net Actuarial Loss
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(700,384)	(560,153)	(620,292)
Amortization	22,692	20,773	20,267
Pension lump sum settlement	27,391
Other current period change	(6,012)	(62,017)	39,872
Adoption of new accounting standard				(98,987)
Ending balance	(656,313)	(700,384)	(560,153)
Prior Service Credit
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(11,537)	(6,910)	(7,130)
Amortization	554	304	219
Pension lump sum settlement	0
Other current period change	(163)	(3,351)	1
Adoption of new accounting standard				(1,580)
Ending balance	(11,146)	(11,537)	(6,910)
Accumulated Other Comprehensive Loss
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(911,634)	(710,836)	(834,032)
Adoption of new accounting standard				$ (100,567)
Ending balance	$ (836,491)	$ (911,634)	$ (710,836)