Basis of Presentation - Narrative Policies (Details) - USD ($) shares in Millions		3 Months Ended		9 Months Ended
	Jan. 01, 2021	Mar. 31, 2021	Jun. 30, 2020	Sep. 30, 2021	Dec. 31, 2020	May 31, 2020
Debt Instrument [Line Items]
Equity component		$ (202,000,000)	$ 230,000,000
Deferred tax provision		44,000,000	(25,000,000)
Retained earnings				$ 4,087,000,000	$ 3,478,000,000
Issuance costs and discounts, net				46,000,000	$ 248,000,000
Additional Paid-in Capital
Debt Instrument [Line Items]
Equity component		(230,000,000)	230,000,000	(230,000,000)
Deferred tax provision		50,000,000	$ (25,000,000)	50,000,000
Retained Earnings
Debt Instrument [Line Items]
Equity component		28,000,000		28,000,000
Deferred tax provision		$ (6,000,000)		$ (6,000,000)
Cumulative Effect, Period of Adoption, Adjustment | Accounting Standards Update 2020-06
Debt Instrument [Line Items]
Retained earnings	$ 22,000,000
Issuance costs and discounts, net	(202,000,000)
Deferred tax liabilities	$ 44,000,000
Incremental shares (in shares)	12
0.250% convertible senior notes due 2025
Debt Instrument [Line Items]
Stated interest rate				0.25%
Issuance costs and discounts, net				$ (17,000,000)
0.250% convertible senior notes due 2025 | Senior notes
Debt Instrument [Line Items]
Principal						$ 1,300,000,000
Stated interest rate						0.25%