GOODWILL AND INTANGIBLE ASSETS - Gross Carrying Amount and Accumulated Amortization of Intangible Assets (Detail) - USD ($) $ in Millions	Mar. 31, 2017	Sep. 30, 2016
Finite Lived Intangible Assets [Line Items]
Finite lived intangible assets, gross	$ 136.5	$ 137.5
Accumulated Amortization	(68.7)	(62.2)
Net Carrying Amount	67.8	75.3
Indefinite intangible assets	8.8	8.8
Total intangible assets	145.3	146.3
Total intangible assets, net	76.6	84.1	[1]
Technologies and patents
Finite Lived Intangible Assets [Line Items]
Finite lived intangible assets, gross	98.7	99.6
Accumulated Amortization	(54.0)	(50.2)
Net Carrying Amount	44.7	49.4
Customer contracts and supplier relationship
Finite Lived Intangible Assets [Line Items]
Finite lived intangible assets, gross	32.3	32.3
Accumulated Amortization	(12.4)	(10.8)
Net Carrying Amount	19.9	21.5
Other
Finite Lived Intangible Assets [Line Items]
Finite lived intangible assets, gross	5.5	5.6
Accumulated Amortization	(2.3)	(1.2)
Net Carrying Amount	$ 3.2	$ 4.4

[1] The condensed consolidated balance sheet as of September 30, 2016 was derived from audited financial statements as of that date, but does not include all disclosures required by accounting principles generally accepted in the United States of America.