Commitments And Contingencies (Operating Expense Purchase Obligations) (Details) (USD $) In Millions, unless otherwise specified	6 Months Ended
	Jun. 30, 2014
Long-term Purchase Commitment [Line Items]
Minimum future commitments	$ 2,423
Individual commitments incurred	1
IPL [Member]
Long-term Purchase Commitment [Line Items]
Minimum future commitments	1,902
WPL [Member]
Long-term Purchase Commitment [Line Items]
Minimum future commitments	518
DAEC (IPL) [Member]
Long-term Purchase Commitment [Line Items]
Minimum future commitments	1,589	[1]
DAEC (IPL) [Member] | IPL [Member]
Long-term Purchase Commitment [Line Items]
Minimum future commitments	1,589	[1]
DAEC (IPL) [Member] | WPL [Member]
Long-term Purchase Commitment [Line Items]
Minimum future commitments	0	[1]
Other [Member]
Long-term Purchase Commitment [Line Items]
Minimum future commitments	33	[2]
Other [Member] | IPL [Member]
Long-term Purchase Commitment [Line Items]
Minimum future commitments	20	[2]
Other [Member] | WPL [Member]
Long-term Purchase Commitment [Line Items]
Minimum future commitments	10	[2]
Purchased Power [Member]
Long-term Purchase Commitment [Line Items]
Minimum future commitments	1,824	[1]
Purchased Power [Member] | IPL [Member]
Long-term Purchase Commitment [Line Items]
Minimum future commitments	1,590	[1]
Purchased Power [Member] | WPL [Member]
Long-term Purchase Commitment [Line Items]
Minimum future commitments	234	[1]
Natural Gas [Member]
Long-term Purchase Commitment [Line Items]
Minimum future commitments	253
Natural Gas [Member] | IPL [Member]
Long-term Purchase Commitment [Line Items]
Minimum future commitments	135
Natural Gas [Member] | WPL [Member]
Long-term Purchase Commitment [Line Items]
Minimum future commitments	118
Coal [Member]
Long-term Purchase Commitment [Line Items]
Minimum future commitments	279	[3]
Coal [Member] | IPL [Member]
Long-term Purchase Commitment [Line Items]
Minimum future commitments	123	[3]
Coal [Member] | WPL [Member]
Long-term Purchase Commitment [Line Items]
Minimum future commitments	156	[3]
SO2 emission allowances [Member]
Long-term Purchase Commitment [Line Items]
Minimum future commitments	34
SO2 emission allowances [Member] | IPL [Member]
Long-term Purchase Commitment [Line Items]
Minimum future commitments	34
SO2 emission allowances [Member] | WPL [Member]
Long-term Purchase Commitment [Line Items]
Minimum future commitments	0
Purchased Power [Member] | Other [Member]
Long-term Purchase Commitment [Line Items]
Minimum future commitments	235	[1]
Purchased Power [Member] | Other [Member] | IPL [Member]
Long-term Purchase Commitment [Line Items]
Minimum future commitments	1	[1]
Purchased Power [Member] | Other [Member] | WPL [Member]
Long-term Purchase Commitment [Line Items]
Minimum future commitments	$ 234	[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 June 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 June 30, 2014 regarding expected future usage, which is subject to change.