Derivative Instruments (Credit-Risk-Related Contingent Features) (Details) (USD $)	Jun. 30, 2013	Dec. 31, 2012
Derivative [Line Items]
Fair value of derivative instruments with credit-risk-related contingent features that were in a liability position	$ 1,800,000,000	$ 1,800,000,000
Total required posted collateral should FPL's and Capital Holdings' credit ratings fall to BBB/Baa2	400,000,000	400,000,000
Total required posted collateral should FLP's and Capital Holdings' credit ratings fall below investment grade	2,200,000,000	2,300,000,000
Additional collateral requirements if non-ratings based contract provisions are triggered	800,000,000	700,000,000
Letters of credit posted through the normal course of business that could be applied toward the collateral requirements related to derivative instruments with credit-risk-related contingent features	85,000,000	150,000,000
FPL [Member]
Derivative [Line Items]
Fair value of derivative instruments with credit-risk-related contingent features that were in a liability position	64,000,000	32,000,000
Total required posted collateral should FPL's and Capital Holdings' credit ratings fall to BBB/Baa2	30,000,000	20,000,000
Total required posted collateral should FLP's and Capital Holdings' credit ratings fall below investment grade	500,000,000	500,000,000
Additional collateral requirements if non-ratings based contract provisions are triggered	150,000,000	100,000,000
Letters of credit posted through the normal course of business that could be applied toward the collateral requirements related to derivative instruments with credit-risk-related contingent features	$ 0	$ 0