Receivables (Details) - Impaired loans (USD $) In Millions, unless otherwise specified	12 Months Ended
	Sep. 30, 2013	Sep. 30, 2012
Recorded investment	$ 80.7	$ 77.5
Unpaid principal face	80.8	77.5
Related allowance	63.4	59.9
Average recorded investment	79.1	83.4
Interest income recognized on impaired loans	0.5	0
Contracts [Member]
Recorded investment	5.7	2.5
Unpaid principal face	5.8	2.5
Related allowance	2.6	1.4
Average recorded investment	4.1	3.9
Notes [Member]
Recorded investment	75.0	75.0
Unpaid principal face	75.0	75.0
Related allowance	60.8	58.5
Average recorded investment	$ 75.0	$ 79.5