Regulatory Matters (Regulatory Liabilities) (Details) - USD ($) $ in Millions	Jun. 30, 2024	Dec. 31, 2023
Regulatory Liabilities [Line Items]
Regulatory liabilities	$ 1,136	$ 1,130
Tax-related [Member]
Regulatory Liabilities [Line Items]
Regulatory liabilities	601	566
Cost of removal obligations [Member]
Regulatory Liabilities [Line Items]
Regulatory liabilities	374	366
Derivatives [Member]
Regulatory Liabilities [Line Items]
Regulatory liabilities	50	65
Commodity cost recovery [Member]
Regulatory Liabilities [Line Items]
Regulatory liabilities	51	48
Other [Member]
Regulatory Liabilities [Line Items]
Regulatory liabilities	60	85
IPL [Member]
Regulatory Liabilities [Line Items]
Regulatory liabilities	618	644
IPL [Member] | Tax-related [Member]
Regulatory Liabilities [Line Items]
Regulatory liabilities	296	299
IPL [Member] | Cost of removal obligations [Member]
Regulatory Liabilities [Line Items]
Regulatory liabilities	232	242
IPL [Member] | Derivatives [Member]
Regulatory Liabilities [Line Items]
Regulatory liabilities	30	34
IPL [Member] | Commodity cost recovery [Member]
Regulatory Liabilities [Line Items]
Regulatory liabilities	16	13
IPL [Member] | Other [Member]
Regulatory Liabilities [Line Items]
Regulatory liabilities	44	56
WPL [Member]
Regulatory Liabilities [Line Items]
Regulatory liabilities	518	486
WPL [Member] | Tax-related [Member]
Regulatory Liabilities [Line Items]
Regulatory liabilities	305	267
WPL [Member] | Cost of removal obligations [Member]
Regulatory Liabilities [Line Items]
Regulatory liabilities	142	124
WPL [Member] | Derivatives [Member]
Regulatory Liabilities [Line Items]
Regulatory liabilities	20	31
WPL [Member] | Commodity cost recovery [Member]
Regulatory Liabilities [Line Items]
Regulatory liabilities	35	35
WPL [Member] | Other [Member]
Regulatory Liabilities [Line Items]
Regulatory liabilities	$ 16	$ 29