Derivative Instruments (Credit Risk Disclosures) (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012
Derivative [Line Items]
Derivative, Net Liability Position, Aggregate Fair Value	$ 2,100,000,000	$ 1,800,000,000
Additional Collateral Aggregate Fair Value Due To Credit Rating Downgrade To Bbb Or Baa2	400,000,000	400,000,000
Additional Collateral Aggregate Fair Value Due To Credit Rating Downgrade To Below Investment Grade	2,300,000,000	2,300,000,000
Additional Collateral Aggregate Fair Value Due To Other Financial Measures	800,000,000	700,000,000
Letters Of Credit Already Posted Aggregate Fair Value	210,000,000	150,000,000
FPL [Member]
Derivative [Line Items]
Derivative, Net Liability Position, Aggregate Fair Value	9,000,000	32,000,000
Additional Collateral Aggregate Fair Value Due To Credit Rating Downgrade To Bbb Or Baa2	20,000,000	20,000,000
Additional Collateral Aggregate Fair Value Due To Credit Rating Downgrade To Below Investment Grade	400,000,000	500,000,000
Additional Collateral Aggregate Fair Value Due To Other Financial Measures	150,000,000	100,000,000
Letters Of Credit Already Posted Aggregate Fair Value	$ 0	$ 0