Acquisitions (Schedule of Merger Related Costs) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Business Acquisition [Line Items]
Transition services		$ 0		$ 18
Professional fees (bank, legal, consulting)		0		1
Contract buyouts, terminations and transfers		1		3
Due diligence and environmental		1		2
Employee-related		0		1
Other		0		2
Merger-related expenses	$ 0	2	$ 0	27
Indigo Merger
Business Acquisition [Line Items]
Transition services		0		0
Professional fees (bank, legal, consulting)		0		0
Contract buyouts, terminations and transfers		1		1
Due diligence and environmental		0		1
Employee-related		0		0
Other		0		0
Merger-related expenses		1		2
GEPH Merger
Business Acquisition [Line Items]
Transition services		0		18
Professional fees (bank, legal, consulting)		0		1
Contract buyouts, terminations and transfers		0		2
Due diligence and environmental		1		1
Employee-related		0		1
Other		0		2
Merger-related expenses		$ 1		$ 25