Commitments And Contingencies (Narrative) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014
Long-term Purchase Commitment [Line Items]
Minimum future commitments	$ 2,360
Performance guarantees outstanding	251
Present value abandonment obligation	35
Minimum [Member]
Long-term Purchase Commitment [Line Items]
Warranty period	12 months
Maximum [Member]
Long-term Purchase Commitment [Line Items]
Warranty period	60 months
Performance guarantees outstanding, 2015 [Member]
Long-term Purchase Commitment [Line Items]
Performance guarantees outstanding	128
Performance guarantees outstanding, 2016 [Member]
Long-term Purchase Commitment [Line Items]
Performance guarantees outstanding	48
Performance guarantees outstanding, 2017 [Member]
Long-term Purchase Commitment [Line Items]
Performance guarantees outstanding	75
Capital Purchase Obligation [Member]
Long-term Purchase Commitment [Line Items]
Minimum future commitments	25
DAEC IPL [Member]
Long-term Purchase Commitment [Line Items]
Minimum future commitments	1,538	[1],[2]
IPL [Member]
Long-term Purchase Commitment [Line Items]
Minimum future commitments	1,859
Number of sites monitoring and/or remediating (in sites)	25
IPL [Member] | Capital Purchase Obligation [Member]
Long-term Purchase Commitment [Line Items]
Minimum future commitments	6
WPL [Member]
Long-term Purchase Commitment [Line Items]
Minimum future commitments	499
Number of sites monitoring and/or remediating (in sites)	5
WPL [Member] | Capital Purchase Obligation [Member]
Long-term Purchase Commitment [Line Items]
Minimum future commitments	19
Environmental Issue [Member] | WPL [Member]
Long-term Purchase Commitment [Line Items]
Damages awarded	$ 7

[1] Includes commitments incurred under a PPA, which grants IPL rights to purchase up to 431 MWs of capacity and the resulting energy from DAEC for a term through December 31, 2025. If energy delivered is less than the targeted energy amount, an adjustment payment will be made to IPL, which will be reflected in IPL’s fuel adjustment clause.

[2] Includes payments required by PPAs for capacity rights and minimum quantities of MWhs required to be purchased. Refer to Note 18 for additional information on purchased power transactions.