Stock-Based Compensation (Details) (USD $) In Millions, except Share data, unless otherwise specified	1 Months Ended	3 Months Ended		9 Months Ended		1 Months Ended	9 Months Ended
	Feb. 28, 2009 Plan	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012	Jan. 31, 2012 2009 Stock Plan Stock Options [Member]	Jun. 30, 2013 2009 Stock Plan Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award
Number of additional shares authorized under the plan (in shares)						6,000,000
Number of outstanding plans as of approval date of the 2009 Stock Plan (in plans)	2
Period over which awards are exercisable in equal installments, beginning with the first anniversary of the date of grant of awards (in years)							3 years
Tenure of award (in years)							7 years
Common stock reserved for issuance stock awards (in shares)							9,796,512
Stock-based compensation expense		$ 4.4	$ 3.4	$ 23.1	$ 13.6
Stock-based compensation expense, net of tax		$ 2.7	$ 2.1	$ 14.6	$ 8.6