Income Taxes (Summary Of Tax Credit Carryforwards) (Details) $ in Millions	Dec. 31, 2022 USD ($)
State [Member]
Tax carryforwards, net operating losses	$ 527
State [Member] | IPL [Member]
Tax carryforwards, net operating losses	10
State [Member] | WPL [Member]
Tax carryforwards, net operating losses	1
Federal [Member]
Tax carryforwards, tax credits	672
Federal [Member] | IPL [Member]
Tax carryforwards, tax credits	450
Federal [Member] | WPL [Member]
Tax carryforwards, tax credits	$ 209