Accumulated Other Comprehensive Loss - Changes in Accumulated Other Comprehensive (Loss) by Component (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
AOCI Attributable to Parent [Roll Forward]
Beginning balance	$ 3,674,707
Other comprehensive loss before reclassifications	(103,416)	$ 10,109
Amounts reclassified from accumulated other comprehensive loss	32,352	32,316
Other comprehensive income (loss), net of income taxes	(71,064)	42,425
Ending balance	2,849,275
Pension and Other Post-Retirement Benefits
AOCI Attributable to Parent [Roll Forward]
Beginning balance	(704,415)	(626,322)
Other comprehensive loss before reclassifications	0	0
Amounts reclassified from accumulated other comprehensive loss	16,292	9,665
Other comprehensive income (loss), net of income taxes	16,292	9,665
Ending balance	(688,123)	(739,183)
Pension and Other Post-Retirement Benefits | Cumulative Effect, Period of Adoption, Adjustment
AOCI Attributable to Parent [Roll Forward]
Beginning balance		(122,526)
Net Investment Hedge
AOCI Attributable to Parent [Roll Forward]
Beginning balance	(20,671)	(4,631)
Other comprehensive loss before reclassifications	(21,046)	(10,827)
Amounts reclassified from accumulated other comprehensive loss	4,704	(4,386)
Other comprehensive income (loss), net of income taxes	(16,342)	(15,213)
Ending balance	(37,013)	(19,844)
Net Investment Hedge | Cumulative Effect, Period of Adoption, Adjustment
AOCI Attributable to Parent [Roll Forward]
Beginning balance		0
Foreign Currency Translation
AOCI Attributable to Parent [Roll Forward]
Beginning balance	(416,222)	(484,125)
Other comprehensive loss before reclassifications	(82,370)	20,936
Amounts reclassified from accumulated other comprehensive loss	11,356	27,037
Other comprehensive income (loss), net of income taxes	(71,014)	47,973
Ending balance	(487,236)	(436,152)
Foreign Currency Translation | Cumulative Effect, Period of Adoption, Adjustment
AOCI Attributable to Parent [Roll Forward]
Beginning balance		0
Total
AOCI Attributable to Parent [Roll Forward]
Beginning balance	(1,141,308)	(1,115,078)
Ending balance	$ (1,212,372)	(1,195,179)
Total | Cumulative Effect, Period of Adoption, Adjustment
AOCI Attributable to Parent [Roll Forward]
Beginning balance		$ (122,526)