Commitments and Contingencies - Additional Information (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Aug. 31, 2020	Jun. 30, 2017
Debt Instrument [Line Items]
Operating lease costs	$ 23,000,000	$ 21,000,000	$ 46,000,000	$ 40,000,000
Operating lease liabilities, payments			37,000,000	26,000,000
Right-of-use assets obtained in exchange for operating lease liabilities			$ 51,000,000	$ 94,000,000
Weighted-average lease remaining lease term	8 years 1 month 6 days		8 years 1 month 6 days
Weighted-average discount rate	3.30%		3.30%
Undiscounted cash flows			$ 341,000,000
Unrecognized tax benefits	$ 25,000,000		25,000,000
Letters of credit	21,000,000		21,000,000
2022 Notes
Debt Instrument [Line Items]
Principal	$ 104,000,000		$ 104,000,000			$ 782,500,000
2030 Notes
Debt Instrument [Line Items]
Principal					$ 1,500,000,000
Minimum
Debt Instrument [Line Items]
Operating lease term	4 years		4 years
Maximum
Debt Instrument [Line Items]
Operating lease term	14 years		14 years