Receivables (Maximum And Average Outstanding Cash Proceeds) (Details) - IPL [Member] - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Receivables [Line Items]
Outstanding aggregate cash proceeds (based on daily outstanding balances)	$ 41.2	$ 54.5	$ 62.1	$ 38.9
Maximum [Member]
Receivables [Line Items]
Outstanding aggregate cash proceeds (based on daily outstanding balances)	$ 137.0	$ 92.0	$ 137.0	$ 92.0