Goodwill and Other Intangible Assets (Goodwill) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Changes in the Carrying Amount of Goodwill by Segment [Roll Forward]
Balance at beginning of period	$ 2,248
Sale of Safari Holdings	0	$ (53)
Balance at end of period	2,247	2,248
Goodwill, Period Increase (Decrease)	(1)	1,586
Goodwill		2,248	$ 715
Kentucky Regulated [Member]
Changes in the Carrying Amount of Goodwill by Segment [Roll Forward]
Balance at beginning of period	662	662
Sale of Safari Holdings	0	0
Balance at end of period	662	662
Goodwill, Period Increase (Decrease)	0	0
Corporate And Other [Member]
Changes in the Carrying Amount of Goodwill by Segment [Roll Forward]
Balance at beginning of period	861	53
Sale of Safari Holdings	0	(53)
Balance at end of period	860	861
Goodwill, Period Increase (Decrease)	(1)	861
Rhode Island Regulated
Changes in the Carrying Amount of Goodwill by Segment [Roll Forward]
Balance at beginning of period	725	0
Sale of Safari Holdings	0	0
Balance at end of period	725	725
Goodwill, Period Increase (Decrease)	$ 0	$ 725