Income Taxes - Narrative (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Provision for (benefit from) income taxes		$ 66,314	$ 664,510	$ 70,571	$ 614,402
Net discrete tax (expense) benefit		(42,100)	(561,500)	(44,300)	(558,800)
Tax expense related to deemed repatriation of accumulated foreign earnings		9,300
Tax expense related to indefinite reinvestment assertion		14,600
Tax expense related to reassessments of prior year tax liabilities		17,800
Gross tax related to the Tax Act	$ 268,500
Release of valuation allowance related to the Tax Act	259,200
Prior year foreign earnings that will not be indefinitely reinvested	300,000	300,000		300,000
Reasonably possible changes to unrecognized tax benefits related to settlement of tax audits and/or expiration of statutes of limitations within the next twelve months						$ 3,500
Income Tax Contingency [Line Items]
Cumulative effect recognized on initial application of the new guidance	$ 1,614,343	$ 1,614,343	$ 2,460,224	$ 1,614,343	$ 2,460,224			$ 2,179,358
Accounting Standards Update 2016-16
Income Tax Contingency [Line Items]
Cumulative effect recognized on initial application of the new guidance							$ 9,000