Income Taxes Income tax (tables) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2014	Mar. 31, 2013
Income Tax Expense (Benefit)	$ 3.1	$ 2.5	$ 3.4	$ 0.9
Operating Expense [Member]
Income Tax Expense (Benefit)	5.1	3.9	5.6	1.5
Valuation Allowance of Deferred Tax Assets [Member]
Income Tax Expense (Benefit)	0	(1.3)	0	(0.5)
Effect of Change in Marginal Tax Rate [Member]
Income Tax Expense (Benefit)	(2.0)	0	(2.0)	0
Other Expense [Member]
Income Tax Expense (Benefit)	$ 0	$ (0.1)	$ (0.2)	$ (0.1)