Debt - Schedule of Notes Payable (Details) - USD ($) $ in Millions	Sep. 30, 2021	Dec. 31, 2020
Debt Instrument [Line Items]
Current, net of unamortized debt discount and issuance costs of $3 million	$ 93	$ 0
Long-term, net of unamortized debt discount and issuance costs of $16 million and $29 million, respectively	1,484	1,640
2030 Notes
Debt Instrument [Line Items]
Current, net of unamortized debt discount and issuance costs of $3 million	0	0
Long-term, net of unamortized debt discount and issuance costs of $16 million and $29 million, respectively	1,484	1,482
Total debt	$ 1,484	1,482
Effective interest rate	1.53%
Unamortized debt discount and issuance costs, long-term	$ 16	16
2022 Notes
Debt Instrument [Line Items]
Current, net of unamortized debt discount and issuance costs of $3 million	93	0
Long-term, net of unamortized debt discount and issuance costs of $16 million and $29 million, respectively	0	158
Total debt	$ 93	158
Effective interest rate	4.75%
Unamortized debt discount and issuance costs, current	$ 3
Unamortized debt discount and issuance costs, long-term		$ 29