Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Sep. 30, 2015
Income Tax Disclosure [Abstract]
Effective income tax rate	21.70%	25.50%
U.S. statutory rate	35.00%	35.00%
Gross unrecognized tax benefits	$ 44.3		$ 43.9
Accrued interest and penalties related to unrecognized tax benefits	5.3		$ 5.1
Net reduction of income tax provision related to unrecognized tax benefits, tax penalties, accrued interest and offsetting tax assets	27.1
Reasonably possible amount of decrease in gross unrecognized tax benefits for the next twelve months	31.8
Reasonably possible amount of net reduction to income tax provision if unrecognized tax benefits were recognized	$ 15.2
Earliest open year for income tax examinations, U.S. federal	2012
Earliest open tax year for income tax examinations, state, local and non-U.S.	2003