Commitments And Contingencies (Operating Expense Purchase Obligations) (Details) (USD $) In Millions, unless otherwise specified	9 Months Ended
	Sep. 30, 2014
Commitments and Contingencies [Line Items]
Minimum future commitments	$ 2,438
Individual commitments incurred	1
IPL [Member]
Commitments and Contingencies [Line Items]
Minimum future commitments	1,922
Individual commitments incurred	1
WPL [Member]
Commitments and Contingencies [Line Items]
Minimum future commitments	514
Individual commitments incurred	1
DAEC (IPL) [Member]
Commitments and Contingencies [Line Items]
Minimum future commitments	1,557	[1]
DAEC (IPL) [Member] | IPL [Member]
Commitments and Contingencies [Line Items]
Minimum future commitments	1,557	[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	20	[2]
Other [Member] | IPL [Member]
Commitments and Contingencies [Line Items]
Minimum future commitments	11	[2]
Other [Member] | WPL [Member]
Commitments and Contingencies [Line Items]
Minimum future commitments	7	[2]
Purchased Power [Member]
Commitments and Contingencies [Line Items]
Minimum future commitments	1,778	[1]
Purchased Power [Member] | IPL [Member]
Commitments and Contingencies [Line Items]
Minimum future commitments	1,558	[1]
Purchased Power [Member] | WPL [Member]
Commitments and Contingencies [Line Items]
Minimum future commitments	220	[1]
Natural Gas [Member]
Commitments and Contingencies [Line Items]
Minimum future commitments	341
Natural Gas [Member] | IPL [Member]
Commitments and Contingencies [Line Items]
Minimum future commitments	191
Natural Gas [Member] | WPL [Member]
Commitments and Contingencies [Line Items]
Minimum future commitments	150
Coal [Member]
Commitments and Contingencies [Line Items]
Minimum future commitments	265	[3]
Coal [Member] | IPL [Member]
Commitments and Contingencies [Line Items]
Minimum future commitments	128	[3]
Coal [Member] | WPL [Member]
Commitments and Contingencies [Line Items]
Minimum future commitments	137	[3]
SO2 emission allowances [Member]
Commitments and Contingencies [Line Items]
Minimum future commitments	34
SO2 emission allowances [Member] | IPL [Member]
Commitments and Contingencies [Line Items]
Minimum future commitments	34
SO2 emission allowances [Member] | WPL [Member]
Commitments and Contingencies [Line Items]
Minimum future commitments	0
Purchased Power [Member] | Other [Member]
Commitments and Contingencies [Line Items]
Minimum future commitments	221	[1]
Purchased Power [Member] | Other [Member] | IPL [Member]
Commitments and Contingencies [Line Items]
Minimum future commitments	1	[1]
Purchased Power [Member] | Other [Member] | WPL [Member]
Commitments and Contingencies [Line Items]
Minimum future commitments	$ 220	[1]

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

[2] Includes individual commitments incurred during the normal course of business that exceeded $1 million at September 30, 2014.

[3] 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 September 30, 2014 regarding expected future usage, which is subject to change.