Contractual interest rate for funds borrowed, under the debt agreement.

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Subsequent Events (Details) - USD ($) shares in Millions, $ in Millions	1 Months Ended	9 Months Ended
	Oct. 31, 2021	Sep. 30, 2021	Sep. 30, 2020
Subsequent events
Debt retirement		$ 374	$ 2,748
Aggregate cash payment		62	867
Proceeds from issuance of shares		141
Subsequent Events
Subsequent events
Debt retirement	$ 28
Aggregate cash payment	28
Proceeds from issuance of shares	$ 17
Aggregate sale of shares (in shares)	4.3
5.875% Senior Secured Notes due January 2024
Subsequent events
Debt retirement		$ 41
Debt instrument interest rate stated percentage		5.875%
5.875% Senior Secured Notes due January 2024 \| Subsequent Events
Subsequent events
Debt instrument interest rate stated percentage	5.875%
5.375% Senior Secured Notes due May 2023
Subsequent events
Debt retirement		$ 10	$ 21
Debt instrument interest rate stated percentage		5.375%
5.375% Senior Secured Notes due May 2023 \| Subsequent Events
Subsequent events
Debt instrument interest rate stated percentage	5.375%