Receivables (Maximum And Average Outstanding Cash Proceeds) (Details) (IPL [Member], USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Accounts, Notes, Loans and Financing Receivable [Line Items]
Costs incurred	$ 1.1	$ 1.4	$ 1.5
Maximum [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Outstanding aggregate cash proceeds (based on daily outstanding balances)	170.0	160.0	160.0
Average [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Outstanding aggregate cash proceeds (based on daily outstanding balances)	$ 105.9	$ 119.8	$ 118.1