Receivables, net - Summary of Analysis of Allowance for Doubtful Trade Accounts Receivables (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2014
Allowance for Doubtful Accounts Receivable [Roll Forward]
Balance at Beginning of Period	$ 44.0	$ 48.6	$ 37.4
Charged to Costs and Expenses	15.6	6.0	7.4
Deductions	(12.0)	(6.3)	(2.4)
Other Adjustments	(0.8)	(4.3)	6.2
Balance at End of Period	$ 46.8	$ 44.0	$ 48.6