Divestitures - Schedule of Intercompany Assets and Liabilities of Business Held for Sale (Details) - USD ($) $ in Millions	Sep. 30, 2017	Sep. 30, 2016
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Other assets	$ 137.2	$ 138.3
Disposal Group, Including Discontinued Operation, Assets, Current	28,326.2	26,284.3
Assets	35,849.7	33,580.1
Long Term Debt Current And Non Current	5,774.1	5,525.8
Accounts payable and other current liabilities (Note 14)	1,115.6	983.2
Other liabilities	43.5	28.7
Disposal Group, Including Discontinued Operation, Liabilities, Current	26,350.7	24,553.8
Liabilities	$ 33,902.8	$ 31,762.9