Commitments And Contingencies (MPG Site Estimated Future Costs And Recorded Liabilities) (Details) - Natural Gas Processing Plant [Member] $ in Millions	9 Months Ended
	Sep. 30, 2023 USD ($)
Commitments and Contingencies [Line Items]
Current and non-current environmental liabilities	$ 18
IPL [Member]
Commitments and Contingencies [Line Items]
Current and non-current environmental liabilities	8
WPL [Member]
Commitments and Contingencies [Line Items]
Current and non-current environmental liabilities	10
Minimum [Member]
Commitments and Contingencies [Line Items]
Range of estimated future costs	9
Minimum [Member] | IPL [Member]
Commitments and Contingencies [Line Items]
Range of estimated future costs	5
Minimum [Member] | WPL [Member]
Commitments and Contingencies [Line Items]
Range of estimated future costs	4
Maximum [Member]
Commitments and Contingencies [Line Items]
Range of estimated future costs	36
Maximum [Member] | IPL [Member]
Commitments and Contingencies [Line Items]
Range of estimated future costs	11
Maximum [Member] | WPL [Member]
Commitments and Contingencies [Line Items]
Range of estimated future costs	$ 25