Receivables (Maximum And Average Outstanding Cash Proceeds) (Details) (IPL [Member], USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Accounts, Notes, Loans and Financing Receivable [Line Items]
Costs incurred	$ 0.2	$ 0.4	$ 0.4	$ 0.7
Maximum [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Outstanding aggregate cash proceeds (based on daily outstanding balances)	75.0	150.0	75.0	170.0
Average [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Outstanding aggregate cash proceeds (based on daily outstanding balances)	$ 34.2	$ 125.6	$ 30.9	$ 132.4