Commitments and Contingencies - Additional Information (Detail) - USD ($) $ in Millions		3 Months Ended	9 Months Ended
	Jan. 07, 2015	Dec. 31, 2015	Jun. 30, 2015	Sep. 30, 2015
Commitment And Contingencies [Line Items]
Reserves for legal, environmental and regulatory matters		$ 9.8
Long-term Debt		6,410.9		$ 6,439.1
Commitments and contingencies		125.5
Expiration of partial amount of unfunded, legally binding lending commitments		29.4
Loss Contingency Accrual, Provision		9.2
Maximum [Member]
Commitment And Contingencies [Line Items]
Expiry date of partial amount of notional amount			1 year
Expiry date of remainder part of notional amount			5 years
Minimum [Member]
Commitment And Contingencies [Line Items]
Expiry date of remainder part of notional amount			1 year
Fidelity And Guaranty Life Holdings [Member]
Commitment And Contingencies [Line Items]
Accrued amount of guaranty fund assessments		3.0
Estimated future premium tax deductions		3.0
Spectrum Brands [Member]
Commitment And Contingencies [Line Items]
Environmental costs recognized, capitalized		4.4
FGL [Member]
Commitment And Contingencies [Line Items]
Reserves for legal, environmental and regulatory matters		5.2
Salus Capital Partners L L C [Member]
Commitment And Contingencies [Line Items]
Foreign Currency Contracts, Liability, Fair Value Disclosure		12.5
Haverhill Retirement vs HRG [Member]
Commitment And Contingencies [Line Items]
Litigation Settlement, Expense		0.2
Cressy Plaintiff [Member]
Commitment And Contingencies [Line Items]
Loss Contingency Accrual, Provision		1.3
Estimated Litigation Liability		1.7
Eddie L. Cressy v. Fidelity Guaranty [sic] Life Insurance Company, et. al. [Member]
Commitment And Contingencies [Line Items]
Legal Fees		4.2
Litigation Settlement, Expense		3.3
Dale R. Ludwick, on behalf of Herself and All Others Similarly Situated v. Harbinger Group Inc., Fidelity & Guaranty Life Insurance Company, Raven Reinsurance Company, and Front Street Re (Cayman) Ltd [Member]
Commitment And Contingencies [Line Items]
Loss Contingency, Damages Sought, Value	$ 0.1
Estimated Litigation Liability		1.3
Radioshack [Member] | Salus Capital Partners L L C [Member]
Commitment And Contingencies [Line Items]
Long-term Debt		250.0		$ 250.0
Revolving Loan Facility		585.0
Proposed Settlement [Member] | Kahn v. Philip A. Falcone et al [Member]
Commitment And Contingencies [Line Items]
Litigation Settlement, Amount		3.8
Asset based loan receivables [Member]
Commitment And Contingencies [Line Items]
Commitments and contingencies		$ 39.9