Derivative Instruments (Credit-Risk-Related Contingent Features) (Details) (USD $)	Sep. 30, 2014	Dec. 31, 2013
Derivative [Line Items]
Fair value of derivative instruments with credit-risk-related contingent features that were in a liability position	$ 2,000,000,000	$ 2,100,000,000
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	2,400,000,000	2,300,000,000
Additional collateral requirements if non-ratings based contract provisions are triggered	700,000,000	800,000,000
Collateral Already Posted, Aggregate Fair Value	187,000,000
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	53,000,000	210,000,000
FPL [Member]
Derivative [Line Items]
Fair value of derivative instruments with credit-risk-related contingent features that were in a liability position	59,000,000	9,000,000
Total required posted collateral should FPL's and Capital Holdings' credit ratings fall to BBB/Baa2	20,000,000	20,000,000
Total required posted collateral should FLP's and Capital Holdings' credit ratings fall below investment grade	500,000,000	400,000,000
Additional collateral requirements if non-ratings based contract provisions are triggered	200,000,000	150,000,000
Collateral Already Posted, Aggregate Fair Value	0
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