DISCONTINUED OPERATIONS - Summary of Balance Sheet Components of Discontinued Operations (Details) - USD ($) $ in Millions	Mar. 31, 2018	Sep. 30, 2017	Apr. 01, 2017	Sep. 30, 2016
Discontinued Operations and Disposal Groups [Abstract]
Cash and cash equivalents		$ 0.0	$ 18.9	$ 21.5
Accounts receivable, net			143.0
Inventories			62.0
Prepaid and other current assets			8.4
Property, plant and equipment, net			23.8
Goodwill and intangible assets, net			60.2
Other assets			15.2
Assets held for sale	$ 0.0	$ 0.0	331.5
Accounts payable			51.8
Other current liabilities			71.9
Long-term debt			12.2
Other liabilities			18.8
Liabilities held for sale			$ 154.7