Assets and Liabilities, at Fair Value - Available for Sale Securities in OCI (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2014	Sep. 30, 2014
Assets and Liabilities, at Fair Value [Abstract]
Equity Investments in Exchange Stock - Cost	$ 3.7	$ 3.7
Equity Investments in Exchange Stock - Fair Value	5.3	4.8
Accumulated Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax	1.7	0.7
Deferred Income Taxes, Accumulated Other Comprehensive Income - AFS	$ (1.0)	$ (0.4)