Receivables (Additional Attributes Of Receivables Sold Under The Agreement) (Details) - IPL [Member] - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Receivables [Line Items]
Collections reinvested in receivables	$ 347.9	$ 499.7	$ 1,283.2	$ 1,362.1
Write-off losses (recoveries), net	$ 3.5	$ (0.3)	$ 10.4	$ (0.6)