Derivative Financial Instruments - Additional Information (Detail) (USD $)	3 Months Ended		6 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2014	Mar. 31, 2013	Sep. 30, 2013
Derivative Financial Instruments [Line Items]
Derivative Asset, Fair Value, Gross Asset	$ 273,000,000		$ 273,000,000		$ 221,800,000
Estimated amount of derivative net losses/gains to be reclassified from AOCI into earnings over the next twelve months	0	0	(900,000)	(500,000)
Derivative, Notional Amount	6,801,900,000		6,801,900,000		6,407,400,000
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	69.00%	54.00%	77.00%
Futures contracts [Member]
Derivative Financial Instruments [Line Items]
Cash collateral	8,600,000		8,600,000		5,900,000
Futures contracts	1,990		1,990		1,693
Call options [Member]
Derivative Financial Instruments [Line Items]
Derivative Asset, Collateral, Obligation to Return Cash, Offset	150,000,000		150,000,000		72,000,000
Derivative Asset, Fair Value, Gross Asset	271,500,000		271,500,000		221,800,000
Derivative Asset, Fair Value, Amount Offset Against Collateral	121,500,000		121,500,000		149,800,000
Swap [Member] | Natural Gas Commodity Contract [Member]
Derivative Financial Instruments [Line Items]
Natural Gas, Volume	12,272,000.0		12,272,000.0		16,018,000.0
Swap [Member] | Oil Commodity Contract [Member]
Derivative Financial Instruments [Line Items]
Derivative, Commodity Contract, Oil Volume	205,000.0		205,000.0		375.0
Spectrum Brands [Member]
Derivative Financial Instruments [Line Items]
Derivative, Notional Amount	120,500,000		120,500,000		108,500,000
Cash collateral	500,000		500,000
Spectrum Brands [Member] | Standby Letters of Credit [Member]
Derivative Financial Instruments [Line Items]
Standby letters of credit	0		0		0
Spectrum Brands [Member] | Zinc Commodity Swap Contract [Member]
Derivative Financial Instruments [Line Items]
Contract value	13,700,000		13,700,000
Weight of raw materials under derivative contract			7
Spectrum Brands [Member] | Silver Commodity Swap Contract [Member]
Derivative Financial Instruments [Line Items]
Contract value	300,000		300,000		1,000,000
Derivative, Nonmonetary Notional Amount	15		15		45
Spectrum Brands [Member] | Bronze Commodity Contract [Member]
Derivative Financial Instruments [Line Items]
Contract value	5,700,000		5,700,000
Spectrum Brands [Member] | Foreign exchange contracts [Member]
Derivative Financial Instruments [Line Items]
Contract value	223,100,000		223,100,000
Derivative net loss/gain			1,400,000
Derivative net loss/gain, net of tax benefit/expense			700,000
Derivative net loss/gain, non-controlling interest			1,000,000
Estimated amount of derivative net losses/gains to be reclassified from AOCI into earnings over the next twelve months			1,300,000
Remainder of 2014 [Member] | Swap [Member] | Natural Gas Commodity Contract [Member]
Derivative Financial Instruments [Line Items]
Derivative, Average Forward Price	98.47		98.47
Natural Gas, Volume	12,272,000.0		12,272,000.0
Remainder of 2014 [Member] | Swap [Member] | Oil Commodity Contract [Member]
Derivative Financial Instruments [Line Items]
Derivative, Average Forward Price	4.45		4.45
Derivative, Commodity Contract, Oil Volume	205,000.0		205,000.0
Not Designated as Hedging Instrument [Member]
Derivative Financial Instruments [Line Items]
Derivative Asset, Fair Value, Gross Asset	276,700,000		276,700,000		227,700,000
Cash and Cash Equivalents [Member] | Call options [Member]
Derivative Financial Instruments [Line Items]
Derivative Asset, Collateral, Obligation to Return Cash, Offset	108,900,000		108,900,000		72,000,000
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	1,500,000		1,500,000		0
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	0		0
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	$ 271,500,000		$ 271,500,000		$ 221,800,000