GOODWILL AND INTANGIBLE ASSETS - Future Amortization Expense (Details) - USD ($) $ in Millions	Mar. 31, 2017	Sep. 30, 2016
Goodwill and Intangible Assets Disclosure [Abstract]
Future amortization expense, fiscal year 2017	$ 8.3
Future amortization expense, fiscal year 2018	14.4
Future amortization expense, fiscal year 2019	10.7
Future amortization expense, fiscal year 2020	9.7
Future amortization expense, fiscal year 2021	7.7
Thereafter	17.0
Net Carrying Amount	$ 67.8	$ 75.3