Income Taxes (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013	Sep. 30, 2013
Income Tax Disclosure [Abstract]
Effective income tax rate	34.70%	28.90%	31.00%	29.40%
Effective Income Tax Rate Reconciliation, Change in Deferred Tax Assets Valuation Allowance, Amount		$ 2.3	$ 12.1	$ 2.3
Effective Income Tax Rate Reconciliation, Change in Deferred Tax Assets Valuation Allowance		1.10%	3.60%	0.60%
Effective Income Tax Rate Reconciliation, Prior Year Income Taxes, Amount		4.4		4.4
Effective income tax rate reconciliation, adjustment to reflect positions on previously filed tax returns, basis spread		2.10%		1.10%
Income Tax Reconciliation Tax Reinstatement of Research and Development Credits		0.7		5.3
Effective Income Tax Reconciliation Reinstatement of Research and Development Credits		0.30%		1.30%
Gross unrecognized tax benefits, excluding income tax penalties and interest	43.5		43.5		36.9
Net unrecognized tax benefits, excluding interest and penalties that would affect the Company's net income if recognized	30.1		30.1
Interest and penalties			3.3	1.7
Accruals for payment of interest and penalties	20.6		20.6
Estimated reduction in unrecognized tax benefits due to tax audit resolutions during the next twelve months	$ 16.2		$ 16.2