Other Expenses - Other Expenses Breakout (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2015
Other Expenses [Abstract]
Accretion Expense	$ 0.1	$ 0.4	$ 1.8
General Insurance Expense	2.7	2.1	1.7
Advertising Expense	4.0	5.1	2.7
Technology Services Costs	11.6	7.1	4.7
Supplies and Postage Expense	2.1	1.1	1.2
Clearance Fees	2.6	1.3	1.1
Taxes, Miscellaneous	4.6	4.3	3.7
Other Expenses	9.8	8.0	6.6
Operating Costs and Expenses	$ 37.5	$ 29.4	$ 23.5