Commitments And Contingencies (Operating Expense Purchase Obligations) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2015
Commitments and Contingencies [Line Items]
Minimum future commitments	$ 2,283
Individual commitments incurred	1
IPL [Member]
Commitments and Contingencies [Line Items]
Minimum future commitments	1,795
WPL [Member]
Commitments and Contingencies [Line Items]
Minimum future commitments	488
DAEC (IPL) [Member]
Commitments and Contingencies [Line Items]
Minimum future commitments	1,510	[1]
DAEC (IPL) [Member] | IPL [Member]
Commitments and Contingencies [Line Items]
Minimum future commitments	1,510	[1]
DAEC (IPL) [Member] | WPL [Member]
Commitments and Contingencies [Line Items]
Minimum future commitments	0	[1]
Other [Member]
Commitments and Contingencies [Line Items]
Minimum future commitments	220	[1]
Other [Member] | IPL [Member]
Commitments and Contingencies [Line Items]
Minimum future commitments	1	[1]
Other [Member] | WPL [Member]
Commitments and Contingencies [Line Items]
Minimum future commitments	219	[1]
Purchased Power [Member]
Commitments and Contingencies [Line Items]
Minimum future commitments	1,730	[1]
Purchased Power [Member] | IPL [Member]
Commitments and Contingencies [Line Items]
Minimum future commitments	1,511	[1]
Purchased Power [Member] | WPL [Member]
Commitments and Contingencies [Line Items]
Minimum future commitments	219	[1]
Natural Gas [Member]
Commitments and Contingencies [Line Items]
Minimum future commitments	228
Natural Gas [Member] | IPL [Member]
Commitments and Contingencies [Line Items]
Minimum future commitments	120
Natural Gas [Member] | WPL [Member]
Commitments and Contingencies [Line Items]
Minimum future commitments	108
Coal [Member]
Commitments and Contingencies [Line Items]
Minimum future commitments	264	[2]
Coal [Member] | IPL [Member]
Commitments and Contingencies [Line Items]
Minimum future commitments	113	[2]
Coal [Member] | WPL [Member]
Commitments and Contingencies [Line Items]
Minimum future commitments	151	[2]
SO2 emission allowances [Member]
Commitments and Contingencies [Line Items]
Minimum future commitments	22
SO2 emission allowances [Member] | IPL [Member]
Commitments and Contingencies [Line Items]
Minimum future commitments	22
SO2 emission allowances [Member] | WPL [Member]
Commitments and Contingencies [Line Items]
Minimum future commitments	0
Other [Member]
Commitments and Contingencies [Line Items]
Minimum future commitments	39	[3]
Other [Member] | IPL [Member]
Commitments and Contingencies [Line Items]
Minimum future commitments	29	[3]
Other [Member] | WPL [Member]
Commitments and Contingencies [Line Items]
Minimum future commitments	$ 10	[3]

[1] Includes payments required by PPAs for capacity rights and minimum quantities of MWhs required to be purchased.

[2] Corporate Services entered into system-wide coal contracts on behalf of IPL and WPL that include minimum future commitments. These commitments were assigned to IPL and WPL based on information available as of March 31, 2015 regarding expected future usage, which is subject to change.

[3] Includes individual commitments incurred during the normal course of business that exceeded $1 million at March 31, 2015.