Other Expenses - Other Expenses Breakout (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Mar. 31, 2017	Mar. 31, 2016
Other Expenses [Abstract]
Accretion Expense	$ 0.1	$ 0.1	$ 0.1	$ 0.3
General Insurance Expense	0.8	0.3	1.3	0.7
Advertising Expense	1.2	2.3	2.1	3.0
Technology Services Costs	2.8	1.3	5.7	2.8
Supplies and Postage Expense	0.5	0.3	1.1	0.6
Clearance Fees	0.3	0.3	0.7	0.5
Taxes, Miscellaneous	1.2	1.1	2.3	2.1
Other Expenses	2.5	1.7	4.6	3.7
Other Cost and Expense, Operating	$ 9.4	$ 7.4	$ 17.9	$ 13.7