BASIS OF PREPARATION - Tax Reform (Details) - USD ($) $ in Millions	9 Months Ended	12 Months Ended
Mar. 31, 2018	Jun. 30, 2018
Investments, Owned, Federal Income Tax Note [Line Items]
Impact of rate change on gross deferred tax assets	$ (31.6)
Forecast
Investments, Owned, Federal Income Tax Note [Line Items]
Corporate Federal income tax effective rate (percent)		28.00%

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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