Receivables (Additional Attributes Of Receivables Sold Under The Agreement) (Details) - IPL [Member] - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Receivables [Line Items]
Collections	$ 549.5	$ 347.9	$ 1,550.2	$ 1,283.2
Write-offs, net of recoveries	$ 4.9	$ 3.5	$ 12.9	$ 10.4