Accumulated Other Comprehensive Loss - Components of Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019		Dec. 31, 2018		Dec. 31, 2017
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Balance at beginning of year	$ 5,197,642	[1]	$ 4,620,191
Before reclassifications to income	19,336		(163,676)
Reclassifications to income	16,290		16,132
Other comprehensive income (loss)	35,626		(147,544)		$ 165,969
Balance at end of year	5,804,611		5,197,642	[1]	4,620,191
Foreign Currency Translation Gains (Losses)
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Balance at beginning of year	(419,852)		(274,830)
Before reclassifications to income	66,600		(145,022)
Reclassifications to income	0		0
Other comprehensive income (loss)	66,600		(145,022)
Balance at end of year	(353,252)		(419,852)		(274,830)
Retirement and Postretirement Benefit Plan Adjustments
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Balance at beginning of year	(182,036)		(178,987)
Before reclassifications to income	(47,264)		(16,839)
Reclassifications to income	11,285		13,790
Other comprehensive income (loss)	(35,979)		(3,049)
Balance at end of year	(218,015)		(182,036)		(178,987)
Deferred Loss on Interest Rate Derivative Hedges
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Balance at beginning of year	(7,899)		(8,426)
Before reclassifications to income	0		(1,815)
Reclassifications to income	5,005		2,342
Other comprehensive income (loss)	5,005		527
Balance at end of year	(2,894)		(7,899)		(8,426)
Total
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Balance at beginning of year	(609,787)		(462,243)
Balance at end of year	(574,161)		(609,787)		$ (462,243)
Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Reclassifications before taxes, included in net periodic benefit expense	6,335		2,963
Reclassifications, income tax expense	1,330		622
Accumulated Defined Benefit Plans Adjustment Attributable to Parent
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Reclassifications before taxes, included in net periodic benefit expense	14,380		17,313
Reclassifications, income tax expense	$ 3,095		$ 3,523

[1] Reclassified to conform with current presentation (see Note E)