Goodwill and Other Intangible Assets (Goodwill) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Changes in the Carrying Amount of Goodwill by Segment [Roll Forward]
Balance at beginning of period	$ 716
Goodwill recognized during the period	1,586	$ 0
Sale of Safari Holdings	(53)	0
Balance at end of period	2,248	716
Goodwill		715	$ 715
Kentucky Regulated [Member]
Changes in the Carrying Amount of Goodwill by Segment [Roll Forward]
Balance at beginning of period	662	662
Goodwill recognized during the period	0	0
Sale of Safari Holdings	0	0
Balance at end of period	662	662
Corporate And Other [Member]
Changes in the Carrying Amount of Goodwill by Segment [Roll Forward]
Balance at beginning of period	53	53
Goodwill recognized during the period	861	0
Sale of Safari Holdings	(53)	0
Balance at end of period	861	53
Rhode Island Regulated
Changes in the Carrying Amount of Goodwill by Segment [Roll Forward]
Balance at beginning of period	0	0
Goodwill recognized during the period	725	0
Sale of Safari Holdings	0	0
Balance at end of period	$ 725	$ 0