Derivative Instruments and Hedging Activities (Details 2) Share data in Millions, unless otherwise specified	Jun. 25, 2011 USD ($)	Dec. 25, 2010 USD ($)	Jun. 25, 2011 Cross currency swaps USD ($)	Dec. 25, 2010 Cross currency swaps USD ($)	Jun. 25, 2011 Cross currency swaps Current derivative liability USD ($)	Dec. 25, 2010 Cross currency swaps Current derivative liability USD ($)	Dec. 25, 2010 Cross currency swaps Long term derivative liability USD ($)	Jun. 25, 2011 Foreign currency forwards USD ($)	Dec. 25, 2010 Foreign currency forwards USD ($)	Jun. 25, 2011 Foreign currency forwards Other current assets USD ($)	Dec. 25, 2010 Foreign currency forwards Other current assets USD ($)	Jun. 25, 2011 Foreign currency forwards Other assets USD ($)	Dec. 25, 2010 Foreign currency forwards Other assets USD ($)	Jun. 25, 2011 Foreign currency forwards Current derivative liability USD ($)	Dec. 25, 2010 Foreign currency forwards Current derivative liability USD ($)	Jun. 25, 2011 Foreign currency forwards Long term derivative liability USD ($)	Dec. 25, 2010 Foreign currency forwards Long term derivative liability USD ($)	Jun. 25, 2011 Commodity swaps mJ	Dec. 25, 2010 Commodity swaps mJ	Jun. 25, 2011 Commodity swaps Other current assets USD ($)	Dec. 25, 2010 Commodity swaps Other current assets USD ($)	Jun. 25, 2011 Commodity swaps Other assets USD ($)	Jun. 25, 2011 Commodity swaps Current derivative liability USD ($)	Dec. 25, 2010 Commodity swaps Current derivative liability USD ($)	Jun. 25, 2011 Commodity swaps Long term derivative liability USD ($)	Dec. 25, 2010 Commodity swaps Long term derivative liability USD ($)	Dec. 25, 2010 Total return swaps AUD	Dec. 25, 2010 Total return swaps Other current assets USD ($)	Dec. 25, 2010 Option contracts	Dec. 25, 2010 Option contracts Other current assets USD ($)	Dec. 25, 2010 Option contracts Current derivative liability USD ($)
Derivatives designated as hedging instruments:
Notional Amount			$ 1,691,700,000	$ 1,637,100,000				$ 427,200,000	$ 426,000,000
Notional amount of derivative, designated as hedging instrument, in Gigajoules																		2,000	2,200
Derivative asset, fair value, designated as hedging instrument	2,400,000	500,000								500,000	300,000	700,000	100,000							1,000,000	100,000	200,000
Derivative liability, fair value, designated as hedging instrument	(456,200,000)	(430,200,000)			(437,600,000)	(11,200,000)	(401,000,000)							(13,300,000)	(12,400,000)	(4,600,000)	(3,400,000)						(600,000)	(1,800,000)	(100,000)	(400,000)
Derivatives not designated as hedging instruments:
Notional amount of derivative, not designated as hedging instrument									13,900,000																		42,100,000
Derivative asset, fair value, not designated as hedging instrument		4,300,000																										1,200,000		3,100,000
Derivative liability, fair value, not designated as hedging instrument		$ (1,000,000)													$ (800,000)																$ (200,000)
Notional amount of derivatives not designated as hedging instrument, in FGL.ASX shares (in shares)																													7.6