Income Taxes Income Taxes Prior Period Adjustment (Details) (USD $) In Millions, unless otherwise specified	0 Months Ended	3 Months Ended								12 Months Ended
	Apr. 02, 2012	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2011
Deferred Tax Assets, Valuation Allowance		$ 31.0		$ 23.2		$ 41.9				$ 31.0	$ 41.9
Increase (Decrease) in Deferred Income Taxes										(130.9)	709.5	0
Valuation Allowance, Deferred Tax Asset, Change in Amount	(753.2)	(2.9)		(18.7)		(36.5)	(716.7)
Income Tax Expense (Benefit)		63.3	59.1	31.1	41.6	(0.9)	(715.6)	1.7	1.5	195.1	(713.4)	(59.7)
Scenario, ProForma [Member]
Deferred Tax Assets, Valuation Allowance		(7.1)								(7.1)
Increase (Decrease) in Deferred Income Taxes										31.6
Valuation Allowance, Deferred Tax Asset, Change in Amount										37.6
Income Tax Expense (Benefit)										$ 6.0