Regulatory Matters - Summary of Utilities Rate Plans (Pike-Gas) (Detail) - USD ($) $ in Millions	12 Months Ended	65 Months Ended
Aug. 31, 2015	Aug. 31, 2014
Gas \| Pike County Light & Power Company (Pike)
Public Utilities, General Disclosures [Line Items]
Base rate changes	$ 0.1	$ 0.3

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.

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