Reinsurance - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	9 Months Ended				9 Months Ended	15 Months Ended	0 Months Ended	9 Months Ended
	Jun. 30, 2013	Sep. 30, 2012	Oct. 17, 2011	Apr. 08, 2011	Jun. 30, 2013 Wilton Re [Member]	Jul. 01, 2013 Wilton Re [Member]	Jan. 01, 2013 Fgl Reinsurance Agreement With Fsr [Member]	Jun. 30, 2013 Nomura [Member]
Reinsurance Premiums for Insurance Companies, by Product Segment [Line Items]
ReinsuranceRecissionGainLoss					$ 1.9
Fair value of insurance transferred assets			580.7	535.8
Pre-tax gain on reinsurance transactions deferred	18.0
Reserve financing facility								295.0
Upfront structuring fee								2.8
LetterofCreditFutureQuarterlyReductiun								6.3
Reinsurance arrangment in percentage							10.00%
Payments for reinsurance						6.4	1,500.0
Contractholder funds	$ 15,342.6	$ 15,290.4			$ 4.5