Employee Benefit Plans Employee Benefit Plans (Details Textuals 2) (USD $) In Millions, except Share data, unless otherwise specified	12 Months Ended					12 Months Ended									1 Months Ended	12 Months Ended		1 Months Ended	12 Months Ended			1 Months Ended	3 Months Ended	12 Months Ended			1 Months Ended	12 Months Ended			1 Months Ended	12 Months Ended			1 Months Ended	12 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2011	Mar. 05, 2013	Sep. 02, 2011	Sep. 30, 2013 Employee Stock Option [Member]	Sep. 30, 2012 Employee Stock Option [Member]	Sep. 30, 2011 Employee Stock Option [Member]	Sep. 30, 2013 Employee Stock Option [Member] Minimum [Member]	Sep. 30, 2013 Employee Stock Option [Member] Maximum [Member]	Sep. 30, 2011 Employee Stock Option [Member] November Two Thousand Ten Grant [Member] Minimum [Member]	Sep. 30, 2011 Employee Stock Option [Member] November Two Thousand Ten Grant [Member] Maximum [Member]	Sep. 30, 2013 Employee Stock Option [Member] January Two Thousand Thirteen Grant [Member] Minimum [Member]	Sep. 30, 2013 Employee Stock Option [Member] January Two Thousand Thirteen Grant [Member] Maximum [Member]	Sep. 30, 2010 Restricted Stock Units (RSUs) [Member] September Two Thousand Ten Grant [Member]	Sep. 30, 2012 Restricted Stock Units (RSUs) [Member] September Two Thousand Ten Grant [Member]	Sep. 30, 2011 Restricted Stock Units (RSUs) [Member] September Two Thousand Ten Grant [Member]	Nov. 30, 2012 Performance Shares [Member]	Sep. 30, 2013 Performance Shares [Member]	Sep. 30, 2012 Performance Shares [Member]	Sep. 30, 2011 Performance Shares [Member]	Nov. 30, 2010 Performance Shares [Member] November Two Thousand Ten Grant [Member]	Dec. 31, 2013 Performance Shares [Member] November Two Thousand Ten Grant [Member]	Sep. 30, 2013 Performance Shares [Member] November Two Thousand Ten Grant [Member]	Sep. 30, 2012 Performance Shares [Member] November Two Thousand Ten Grant [Member]	Sep. 30, 2011 Performance Shares [Member] November Two Thousand Ten Grant [Member]	Nov. 30, 2011 Performance Shares [Member] November Two Thousand Eleven Grant [Member]	Sep. 30, 2013 Performance Shares [Member] November Two Thousand Eleven Grant [Member]	Sep. 30, 2012 Performance Shares [Member] November Two Thousand Eleven Grant [Member]	Sep. 30, 2011 Performance Shares [Member] November Two Thousand Eleven Grant [Member]	Nov. 30, 2012 Performance Shares [Member] November Two Thousand Twelve Grant [Member]	Sep. 30, 2013 Performance Shares [Member] November Two Thousand Twelve Grant [Member]	Sep. 30, 2012 Performance Shares [Member] November Two Thousand Twelve Grant [Member]	Sep. 30, 2011 Performance Shares [Member] November Two Thousand Twelve Grant [Member]	Jan. 31, 2013 Performance Shares [Member] January Two Thousand Thirteen Grant [Member]	Sep. 30, 2013 Performance Shares [Member] January Two Thousand Thirteen Grant [Member]	Sep. 30, 2013 Performance Shares [Member] January Two Thousand Thirteen Grant [Member] Minimum [Member]	Sep. 30, 2013 Performance Shares [Member] January Two Thousand Thirteen Grant [Member] Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period									2 years	9 years 9 months	2 years	5 years	2 years	5 years																							1 year	3 years
Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period						10 years						10 years		10 years
Number of shares granted to purchase	3,676,000	0	6,200,000
Shares available for grant	7,500,000
Total intrinsic value of options exercised						$ 14.6	$ 26.4	$ 0.9
Aggregate intrinsic value of options outstanding						104.1
Aggregate intrinsic value of options exercisable						33.9
Lower range of options outstanding exercise price						$ 9.03
Upper range of options outstanding exercise price						$ 36.92
Weighted average remaining contractual term of options outstanding						6 years 0 months
Weighted average remaining contractual term of options exercisable						4 years 6 months
Stock Option Grant Recipients				500	350
Weighted average fair value per share of options granted	$ 10.92		$ 3.98
Stock based compensation expense	19.0	18.1	14.2			18.6	15.1	12.8
Unrecognized compensation expense related to options						61.8
Weighted average period over which unrecognized compensation cost is expected to be recognized						3 years 11 months
Number of units granted															200,000							300,000					350,000				350,000				33,333
Performance period															2 years			3 years
Range of percentage of units vested upon achieving performance criteria, low															0.00%			0.00%
Range of percentage of units vested upon achieving performance criteria, high															200.00%			200.00%
Grant date fair value per unit															$ 11.53							$ 12.69					$ 11.79				$ 22.15				$ 21.49
Number of units earned																325,000								487,500
Stock Issued During Period, Shares, Restricted Stock Award, Net of Forfeitures																							487,500
Stock Issued During Period, Value, Restricted Stock Award, Net of Forfeitures																							9.5
Liabilities for share-based compensation																			19.6	10.8				9.5	6.7			7.4	4.1			2.7	0
Share-based compensation expense																$ 2.6	$ 1.2		$ 8.8	$ 9.8	$ 1.0			$ 2.8	$ 5.7	$ 1.0		$ 3.3	$ 4.1	$ 0		$ 2.7	$ 0	$ 0		$ 0.2