Long-Term Debt and Credit Facilities - Aggregate Principal Senior Notes Retired (Details) - Senior Notes - USD ($) $ in Millions	3 Months Ended		12 Months Ended
	Jun. 30, 2023	Mar. 31, 2023	Dec. 31, 2023	Dec. 31, 2022	Sep. 30, 2022
Long-term Debt and Credit Facilities
Amount of debt redeemed			$ 1,554
5.625% Senior Notes, Series X, due 2025
Long-term Debt and Credit Facilities
Stated interest rate (as a percent)	5.625%	5.625%		5.625%
Amount of debt redeemed	$ 1	$ 48
7.200% Senior Notes, Series D, due 2025
Long-term Debt and Credit Facilities
Stated interest rate (as a percent)		7.20%		7.20%
Amount of debt redeemed		$ 21
5.125% Senior Notes due 2026
Long-term Debt and Credit Facilities
Stated interest rate (as a percent)		5.125%		5.125%	5.125%
Amount of debt redeemed		$ 291
6.875% Debentures, Series G, due 2028
Long-term Debt and Credit Facilities
Stated interest rate (as a percent)		6.875%		6.875%
Amount of debt redeemed		$ 52
5.375% Senior Notes due 2029
Long-term Debt and Credit Facilities
Stated interest rate (as a percent)		5.375%		5.375%
Amount of debt redeemed		$ 275
4.500% Senior Notes due 2029
Long-term Debt and Credit Facilities
Stated interest rate (as a percent)	4.50%	4.50%
Amount of debt redeemed	$ 2	$ 556
7.600% Senior Notes, Series P, due 2039
Long-term Debt and Credit Facilities
Stated interest rate (as a percent)	7.60%	7.60%
Amount of debt redeemed	$ 3	$ 161
7.650% Senior Notes, Series U, due 2042
Long-term Debt and Credit Facilities
Stated interest rate (as a percent)	7.65%	7.65%
Amount of debt redeemed	$ 13	$ 131