Funds Withheld Receivables Net Investment Income (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2014
Schedule of Available-for-sale Securities [Line Items]
Gross Investment Income	$ 67.0	$ 84.3	$ 90.1
Fixed Maturity Available For Sale Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Investment Income	56.0	58.6	55.7
Equity Securities Available For Sale [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Investment Income	2.1	2.6	4.1
Asset based loan receivables [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Investment Income	3.5	16.1	28.4
Other Investments [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Investment Income	$ 5.4	$ 7.0	$ 1.9