Related Party Transactions (Details) - USD ($) $ in Millions	6 Months Ended
Jun. 30, 2015	Jun. 30, 2014	Dec. 31, 2014
Service Company [Member]
Related Party Transaction [Line Items]
Costs incurred by related party	$ 12.2	$ 13.6
Prepaid balance to related party	3.5		$ 0.4
Ipalco Enterprises, Inc. [Member]
Related Party Transaction [Line Items]
Costs incurred by related party	$ 3.7	$ 2.1

Costs of sales and operating expenses for the period incurred from transactions with related parties.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 225

-SubTopic 10

-Section S99

-Paragraph 2

-Subparagraph (SX 210.5-03.2)

-URI http://asc.fasb.org/extlink&oid=26872669&loc=d3e20235-122688

Name:	us-gaap_CostsAndExpensesRelatedParty
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration