Receivables (Narrative) (Details) - Receivables Sold [Member] - IPL [Member] $ in Millions	Sep. 30, 2017 USD ($)
Receivables [Line Items]
Available capacity	$ 1.5
Outstanding receivables past due	$ 54.1

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

No definition available.

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Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration