Commitments And Contingencies (Operating Expense Purchase Obligations) (Details) $ in Millions	6 Months Ended
	Jun. 30, 2016 USD ($)
Commitments and Contingencies [Line Items]
Minimum future commitments	$ 2,175
Individual commitments incurred	1
IPL [Member]
Commitments and Contingencies [Line Items]
Minimum future commitments	1,698
Individual commitments incurred	1
WPL [Member]
Commitments and Contingencies [Line Items]
Minimum future commitments	462
Individual commitments incurred	1
DAEC (IPL) [Member]
Commitments and Contingencies [Line Items]
Minimum future commitments	1,356	[1]
DAEC (IPL) [Member] | IPL [Member]
Commitments and Contingencies [Line Items]
Minimum future commitments	1,356	[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	158	[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	157	[1]
Purchased Power [Member]
Commitments and Contingencies [Line Items]
Minimum future commitments	1,514	[1]
Purchased Power [Member] | IPL [Member]
Commitments and Contingencies [Line Items]
Minimum future commitments	1,357	[1]
Purchased Power [Member] | WPL [Member]
Commitments and Contingencies [Line Items]
Minimum future commitments	157	[1]
Natural Gas [Member]
Commitments and Contingencies [Line Items]
Minimum future commitments	416
Natural Gas [Member] | IPL [Member]
Commitments and Contingencies [Line Items]
Minimum future commitments	239
Natural Gas [Member] | WPL [Member]
Commitments and Contingencies [Line Items]
Minimum future commitments	177
Coal [Member]
Commitments and Contingencies [Line Items]
Minimum future commitments	212	[2]
Coal [Member] | IPL [Member]
Commitments and Contingencies [Line Items]
Minimum future commitments	86	[2]
Coal [Member] | WPL [Member]
Commitments and Contingencies [Line Items]
Minimum future commitments	126	[2]
SO2 emission allowances [Member]
Commitments and Contingencies [Line Items]
Minimum future commitments	8
SO2 emission allowances [Member] | IPL [Member]
Commitments and Contingencies [Line Items]
Minimum future commitments	8
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	25	[3]
Other [Member] | IPL [Member]
Commitments and Contingencies [Line Items]
Minimum future commitments	8	[3]
Other [Member] | WPL [Member]
Commitments and Contingencies [Line Items]
Minimum future commitments	$ 2	[3]

[1] Includes payments required by purchased power agreements 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 June 30, 2016 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 June 30, 2016.