Derivative Financial Instruments - Additional Information (Detail) (USD $)	3 Months Ended		12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Sep. 30, 2014	Jun. 16, 2014	Sep. 30, 2013 MMBTU
Derivative Financial Instruments [Line Items]
Document Period End Date	Dec. 31, 2014
Other invested assets	$ 247,000,000		$ 165,000,000
Derivative, Notional Amount	8,151,500,000		7,602,600,000
Call options purchased to match the funding requirements			Call options are one, two and three year options
FGL purchases call options to fund the next index credit			One, two or three year call options to fund the next index credit
Derivative, Percentage of Production Volume Covered by Derivative Financial Instruments	71.00%	84.00%
Futures contracts [Member]
Derivative Financial Instruments [Line Items]
Cash collateral	7,400,000		10,800,000
Futures contracts	1,627		2,348
Nomura Fund Linked Note [Member]
Derivative Financial Instruments [Line Items]
Other invested assets	11,800,000
Available-for-sale Securities, Debt Securities	22,700,000
Investment Owned, Balance, Principal Amount				35,000,000
Embedded Derivative, Fair Value of Embedded Derivative Liability				11,300,000
Call options [Member]
Derivative Financial Instruments [Line Items]
Derivative Asset, Collateral, Obligation to Return Cash, Offset	213,200,000		188,000,000
Derivative Asset, Fair Value, Gross Asset	306,200,000		296,300,000
Derivative Asset, Fair Value, Amount Offset Against Collateral	93,000,000		108,300,000
Swap [Member] | Natural Gas Commodity Contract [Member]
Derivative Financial Instruments [Line Items]
Natural Gas, Volume					6,821
Swap [Member] | Oil Commodity Contract [Member]
Derivative Financial Instruments [Line Items]
Derivative, Commodity Contract, Oil Volume					254,366.0
Spectrum Brands [Member]
Derivative Financial Instruments [Line Items]
Derivative, Notional Amount	313,700,000		108,900,000
Spectrum Brands [Member] | Standby Letters of Credit [Member]
Derivative Financial Instruments [Line Items]
Standby letters of credit			0		0
Spectrum Brands [Member] | Zinc Commodity Swap Contract [Member]
Derivative Financial Instruments [Line Items]
Contract value	14,700,000
Derivative net loss/gain	200,000
Estimated amount of derivative net losses/gains to be reclassified from AOCI into earnings over the next twelve months	200,000
Weight of raw materials under derivative contract	7,000
Spectrum Brands [Member] | Silver Commodity Swap Contract [Member]
Derivative Financial Instruments [Line Items]
Contract value	300,000		400,000
Derivative, Nonmonetary Notional Amount	20		25
Spectrum Brands [Member] | Bronze Commodity Contract [Member]
Derivative Financial Instruments [Line Items]
Contract value	6,300,000
Spectrum Brands [Member] | Interest Rate Contract [Member]
Derivative Financial Instruments [Line Items]
Derivative, Fixed Interest Rate	1.36%
Derivative net loss/gain	500,000		400,000
Estimated amount of derivative net losses/gains to be reclassified from AOCI into earnings over the next twelve months	900,000		800,000
Derivative, Notional Amount	300,000,000
Spectrum Brands [Member] | Foreign Exchange Contract [Member]
Derivative Financial Instruments [Line Items]
Contract value	157,000,000
Derivative net loss/gain	7,300,000
Derivative net loss/gain, net of tax benefit/expense	2,700,000
Estimated amount of derivative net losses/gains to be reclassified from AOCI into earnings over the next twelve months	7,300,000
Remainder of 2014 [Member] | Swap [Member] | Natural Gas Commodity Contract [Member]
Derivative Financial Instruments [Line Items]
Derivative, Average Forward Price	56.26
Remainder of 2014 [Member] | Swap [Member] | Oil Commodity Contract [Member]
Derivative Financial Instruments [Line Items]
Derivative, Average Forward Price	3.01
Year Two [Member] | Swap [Member] | Natural Gas Commodity Contract [Member]
Derivative Financial Instruments [Line Items]
Natural Gas, Volume	10,950,000.0
Year Two [Member] | Swap [Member] | Oil Commodity Contract [Member]
Derivative Financial Instruments [Line Items]
Derivative, Commodity Contract, Oil Volume	250,000.0
Not Designated as Hedging Instrument [Member]
Derivative Financial Instruments [Line Items]
Derivative Asset, Fair Value, Gross Asset	355,800,000		324,100,000
Cash and Cash Equivalents [Member] | Call options [Member]
Derivative Financial Instruments [Line Items]
Derivative Asset, Collateral, Obligation to Return Cash, Offset	174,800,000		135,500,000
Derivatives For Trading And Investment [Member] | Not Designated as Hedging Instrument [Member] | Futures contracts [Member]
Derivative Financial Instruments [Line Items]
Derivative Asset, Fair Value, Gross Asset	11,800,000
Derivatives For Trading And Investment [Member] | Not Designated as Hedging Instrument [Member] | Commodity contracts [Member]
Derivative Financial Instruments [Line Items]
Derivative Asset, Fair Value, Gross Asset	19,500,000
Derivatives For Trading And Investment [Member] | Not Designated as Hedging Instrument [Member] | Call options [Member]
Derivative Financial Instruments [Line Items]
Derivative Asset, Fair Value, Gross Asset	$ 306,200,000		$ 296,300,000