Derivative Instruments (Credit-Risk-Related Contingent Features) (Details) - USD ($) $ in Millions	Mar. 31, 2016	Dec. 31, 2015
Derivative [Line Items]
Fair value of derivative instruments with credit-risk-related contingent features that were in a liability position	$ 2,400	$ 2,200
Total required posted collateral should FPL's and Capital Holdings' credit ratings fall to BBB/Baa2	350	250
Total required posted collateral should FLP's and Capital Holdings' credit ratings fall below investment grade	2,500	2,500
Additional collateral requirements if non-ratings based contract provisions are triggered	385	660
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	182	123
FPL [Member]
Derivative [Line Items]
Fair value of derivative instruments with credit-risk-related contingent features that were in a liability position	259	224
Total required posted collateral should FPL's and Capital Holdings' credit ratings fall to BBB/Baa2	30	20
Total required posted collateral should FLP's and Capital Holdings' credit ratings fall below investment grade	500	600
Additional collateral requirements if non-ratings based contract provisions are triggered	105	120
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	$ 3