Receivables (Additional Attributes Of Receivables Sold Under The Agreement) (Details) (IPL [Member], USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
IPL [Member]
Receivables [Line Items]
Collections reinvested in receivables	$ 520.1	$ 481.1	$ 1,537.3	$ 1,407.4
Credit losses, net of recoveries	$ 6.4	$ 3.9	$ 12.8	$ 7.8