Derivative Instruments (Income Statement Disclosure) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Not Designated as Hedging Instrument [Member]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net [Abstract]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	$ (6)	$ (71)	$ (290)	$ 83
Not Designated as Hedging Instrument [Member] | Commodity Contract [Member] | Gains (losses) included in operating revenues [Member]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net [Abstract]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	366	(187)	641	(7)
Not Designated as Hedging Instrument [Member] | Foreign Exchange Contract [Member] | Gain Loss Included In Interest Expense Member
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net [Abstract]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	(13)	(17)	(21)	3
Not Designated as Hedging Instrument [Member] | Interest Rate Contract [Member] | Gain Loss Included In Interest Expense Member
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net [Abstract]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	(352)	142	(883)	115
Reclassification out of Accumulated Other Comprehensive Income [Member] | Not Designated as Hedging Instrument [Member] | Foreign Exchange Contract [Member] | Gain Loss Included In Interest Expense Member
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net [Abstract]
Interest Expense	(1)	(1)	(3)	(3)
Reclassification out of Accumulated Other Comprehensive Income [Member] | Not Designated as Hedging Instrument [Member] | Interest Rate Contract [Member] | Gain Loss Included In Interest Expense Member
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net [Abstract]
Interest Expense	(6)	(8)	(24)	(25)
FPL [Member]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net [Abstract]
Gains (losses) on commodity contracts, recorded as regulatory assets and or liabilities on the balance sheet due to regulatory treatment	$ 4	$ (1)	$ 8	$ 4