Income Taxes (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Sep. 30, 2012
Income Tax Disclosure [Abstract]
Effective income tax rate	31.50%	22.30%
Effective income tax rate reconciliation, net discrete tax benefits, basis spread	2.80%	13.40%
Effective income tax rate reconciliation, settlement of foreign tax audit, basis spread		4.80%
Effective income tax rate reconciliation, reduction of tax reserves resulting from lapse of applicable statute of limitations, basis spread		2.00%
Effective income tax rate reconciliation, adjustment to reflect positions on previously filed tax returns, basis spread		6.60%
Gross unrecognized tax benefits, excluding income tax penalties and interest	$ 35.0		$ 33.9
Net unrecognized tax benefits, excluding interest and penalties that would affect the Company's net income if recognized	24.5
Net unrecognized tax benefits, excluding interest and penalties that would affect the Company's net income from continuing operations, if recognized	23.9
Interest and penalties	0.7	(0.6)
Accruals for payment of interest and penalties	14.4
Estimated reduction in unrecognized tax benefits due to tax audit resolutions during the next twelve months	$ 2.5