Debt (Senior Notes - Narrative) (Details) - USD ($) $ in Millions		1 Months Ended	3 Months Ended		6 Months Ended
	Feb. 26, 2023	Jan. 31, 2015	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022	Dec. 31, 2022	May 31, 2022	Jan. 06, 2022	Apr. 07, 2020	Jul. 31, 2018
Debt Instrument [Line Items]
Loss on early extinguishment of debt			$ 0	$ 4	$ 19	$ 6
Senior Notes
Debt Instrument [Line Items]
Repayments of long-term debt					272
Loss on early extinguishment of debt					$ 6
Senior Notes | London Interbank Offered Rate (LIBOR) 1
Debt Instrument [Line Items]
Incremental increase in basis points resulting from downgrades		0.25%
Incremental decrease in basis points resulting from upgrades		0.25%
4.95% Senior Notes due January 2025 | Senior Notes
Debt Instrument [Line Items]
Senior notes, noncurrent		$ 1,000
Stated interest rate		4.95%	4.95%		4.95%		4.95%	5.70%	5.95%	6.45%	6.20%
4.10% Senior Notes due March 2022 | Senior Notes
Debt Instrument [Line Items]
Stated interest rate				4.10%		4.10%
Repurchased amount				$ 201		$ 201
8.375% Senior Notes due September 2028 | Senior Notes
Debt Instrument [Line Items]
Stated interest rate			8.375%	8.375%	8.375%	8.375%	8.375%
Repurchased amount			$ 46		$ 46
7.75% Senior Notes due October 2027 | Senior Notes
Debt Instrument [Line Items]
Stated interest rate	7.75%			7.75%		7.75%	7.75%
Repurchased amount			$ 19		$ 19
Loss on early extinguishment of debt	$ 19
Debt instrument, redemption price, percentage of principal amount redeemed	103.875%
Accrued interest	$ 13
Repayments of senior debt	450
Write off of deferred debt issuance cost	3
7.75% Senior Notes due October 2027 | Senior Notes | Funded from Cash on Hand
Debt Instrument [Line Items]
Repayments of senior debt	316
7.75% Senior Notes due October 2027 | Senior Notes | Funded from Debt Borrowings
Debt Instrument [Line Items]
Repayments of senior debt	$ 134