Income Taxes (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Provision for (benefit from) income taxes	$ (24,025)	$ (13,353)	$ 29,754	$ (19,421)
Effective tax rates	(6.00%)	(11.00%)	3.00%	(5.00%)
Income Tax Contingency [Line Items]
Tax cuts and jobs act, provisional benefit	$ 37,600
Transition tax adjustment	16,500
Remeasurement of deferred tax assets and liabilities	21,100
Unrecognized tax benefits	50,700		$ 50,700		$ 42,900
Reduction in provision for income taxes due to impact of effective tax rate	47,600		47,600
Deferred tax assets classified as other non-current assets	549,300		549,300		478,300
Deferred tax assets, valuation allowance	132,400		132,400		$ 49,400
Other noncurrent liabilities
Income Tax Contingency [Line Items]
Increase in unrecognized tax benefits is reasonably possible	19,000		19,000
Other noncurrent assets
Income Tax Contingency [Line Items]
Unrecognized tax benefits	31,700		31,700
Accounting Standards Update 2016-09
Income Tax Contingency [Line Items]
Effective income tax rate reconciliation, share-based compensation, excess tax benefit	$ 40,100	$ 41,700	$ 157,500	$ 110,500