Segment and Related Information (Income Statement and Balance Sheet Data) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Income Statement Data
Operating Revenues from external customers	$ 8,312	$ 7,902	$ 5,783
Depreciation	1,254	1,181	1,082
Amortization	81	52	39
Interest Expense	666	513	918
Income Before Income Taxes	924	915	521
Income Taxes	184	201	503
Deferred income taxes and investment tax credits	322	179	87
Net income (loss)	740	756	(1,480)
Cash Flow Data
Expenditures for long-lived assets	2,390	2,158	1,979
Balance Sheet Data
Total Assets	39,236	37,837
Kentucky Regulated [Member]
Income Statement Data
Operating Revenues from external customers	3,452	3,811	3,348
Depreciation	696	685	647
Amortization	33	23	15
Interest Expense	235	205	196
Income Before Income Taxes	689	678	615
Income Taxes	137	129	107
Deferred income taxes and investment tax credits	(17)	6	272
Net income (loss)	552	549	508
Cash Flow Data
Expenditures for long-lived assets	950	917	1,026
Balance Sheet Data
Total Assets	17,029	16,904
Pennsylvania Regulated [Member]
Income Statement Data
Operating Revenues from external customers	3,008	3,030	2,402
Depreciation	397	393	424
Amortization	41	22	19
Interest Expense	223	171	162
Income Before Income Taxes	687	699	599
Income Taxes	168	174	154
Deferred income taxes and investment tax credits	46	91	79
Net income (loss)	519	525	445
Cash Flow Data
Expenditures for long-lived assets	956	889	904
Balance Sheet Data
Total Assets	14,294	13,565
Corporate And Other [Member]
Income Statement Data
Operating Revenues from external customers	1	23	33
Depreciation	5	11	11
Amortization	6	5	5
Interest Expense	125	98	560
Income Before Income Taxes	(564)	(404)	(693)
Income Taxes	(137)	(88)	242
Deferred income taxes and investment tax credits	245	43	(264)
Net income (loss)	(427)	(316)	(935)
Cash Flow Data
Expenditures for long-lived assets	30	84	49
Balance Sheet Data
Total Assets	1,398	1,287
Discontinued Operations Segment
Income Statement Data
Net income (loss)	0	42	(1,498)
Rhode Island Regulated
Income Statement Data
Operating Revenues from external customers	1,851	1,038	0
Depreciation	156	92	0
Amortization	1	2	0
Interest Expense	83	39	0
Income Before Income Taxes	112	(58)	0
Income Taxes	16	(14)	0
Deferred income taxes and investment tax credits	48	39	0
Net income (loss)	96	(44)	0
Cash Flow Data
Expenditures for long-lived assets	454	268	$ 0
Balance Sheet Data
Total Assets	$ 6,515	$ 6,081