Regulatory Matters (Regulatory Liabilities) (Details) - USD ($) $ in Millions	Jun. 30, 2025	Dec. 31, 2024
Regulatory Liabilities [Line Items]
Regulatory liabilities	$ 1,088	$ 1,028
Tax-related [Member]
Regulatory Liabilities [Line Items]
Regulatory liabilities	611	582
Cost of removal obligations [Member]
Regulatory Liabilities [Line Items]
Regulatory liabilities	349	347
Derivatives [Member]
Regulatory Liabilities [Line Items]
Regulatory liabilities	60	53
Other [Member]
Regulatory Liabilities [Line Items]
Regulatory liabilities	68	46
IPL [Member]
Regulatory Liabilities [Line Items]
Regulatory liabilities	543	546
IPL [Member] \| Tax-related [Member]
Regulatory Liabilities [Line Items]
Regulatory liabilities	275	286
IPL [Member] \| Cost of removal obligations [Member]
Regulatory Liabilities [Line Items]
Regulatory liabilities	206	205
IPL [Member] \| Derivatives [Member]
Regulatory Liabilities [Line Items]
Regulatory liabilities	32	29
IPL [Member] \| Other [Member]
Regulatory Liabilities [Line Items]
Regulatory liabilities	30	26
WPL [Member]
Regulatory Liabilities [Line Items]
Regulatory liabilities	545	482
WPL [Member] \| Tax-related [Member]
Regulatory Liabilities [Line Items]
Regulatory liabilities	336	296
WPL [Member] \| Cost of removal obligations [Member]
Regulatory Liabilities [Line Items]
Regulatory liabilities	143	142
WPL [Member] \| Derivatives [Member]
Regulatory Liabilities [Line Items]
Regulatory liabilities	28	24
WPL [Member] \| Other [Member]
Regulatory Liabilities [Line Items]
Regulatory liabilities	$ 38	$ 20