Quarterly Financial Data (Narrative) (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended
	Dec. 31, 2023	Sep. 30, 2023	Jun. 30, 2023	Dec. 31, 2022	Sep. 30, 2022
Restructuring Cost and Reserve [Line Items]
Impairment and restructuring, after tax	$ 158
Impairment and restructuring per share, after tax	$ 0.30
Gain (loss) on sale/revaluation of assets after tax	$ (5)	$ 2	$ (8)	$ (13)	$ (22)
Gain (loss) on sale of assets, after tax, per share	$ (0.00)	$ (0.00)	$ (0.02)	$ (0.02)	$ (0.04)
Gain (loss) on embedded derivative			$ (1)	$ 3	$ (8)
Gain (loss) on embedded derivative, per share			$ (0.00)	$ (0.00)	$ (0.01)
Tax expense (benefit) related to certain out of period discretes	$ 1		$ 21	$ 5	$ 7
Tax expense (benefit) related to certain out of period discretes per share	$ 0.00		$ 0.04	$ 0.01	$ 0.01
Impairment, settlement, and restructuring, after tax		$ 54	$ 93	$ 55	$ 40
Impairment, settlement, and restructuring per share, after tax		$ 0.10	$ 0.17	$ 0.10	$ 0.07
Acquisition-related expenses, after-tax	$ 1	$ 3	$ 2
Acquisition-related expenses, per share	$ 0.00	$ 0.01	$ 0.00