Derivative Instruments (Income Statement Disclosure) (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Gains (losses) related to derivatives not designated as hedging instruments [Abstract]
Gains (losses) related to derivatives not designated as hedging instruments	$ (99)	$ 20	$ 80
Disposal Group, Not Discontinued Operation, Gain (Loss) on Disposal	353	406	80
Not Designated as Hedging Instrument [Member] \| Commodity contracts [Member] \| Gains (Losses) Included In Operating Revenues [Member]
Gains (losses) related to derivatives not designated as hedging instruments [Abstract]
Gains (losses) related to derivatives not designated as hedging instruments	352	762	377
Not Designated as Hedging Instrument [Member] \| Commodity contracts [Member] \| Gains (Losses) Included In Fuel, Purchased Power And Interchange [Member]
Gains (losses) related to derivatives not designated as hedging instruments [Abstract]
Gains (losses) related to derivatives not designated as hedging instruments	0	0	(2)
Not Designated as Hedging Instrument [Member] \| Foreign currency contracts [Member] \| Gain (loss) included in interest expense [Member]
Gains (losses) related to derivatives not designated as hedging instruments [Abstract]
Gains (losses) related to derivatives not designated as hedging instruments	8	(7)	19
Not Designated as Hedging Instrument [Member] \| Interest Rate Contract [Member] \| Gain (loss) included in interest expense [Member]
Gains (losses) related to derivatives not designated as hedging instruments [Abstract]
Gains (losses) related to derivatives not designated as hedging instruments	(421)	(699)	(280)
Reclassification out of Accumulated Other Comprehensive Income [Member] \| Not Designated as Hedging Instrument [Member] \| Foreign currency contracts [Member] \| Gain (loss) included in interest expense [Member]
Gains (losses) related to derivatives not designated as hedging instruments [Abstract]
Interest Expense	(3)	(4)	(4)
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]
Gains (losses) related to derivatives not designated as hedging instruments [Abstract]
Interest Expense	(35)	(32)	(30)
Reclassification out of Accumulated Other Comprehensive Income [Member] \| Not Designated as Hedging Instrument [Member] \| Interest Rate Contract [Member] \| Gains (Loss) On Disposal Of Businesses/Assets - Net [Member]
Gains (losses) related to derivatives not designated as hedging instruments [Abstract]
Disposal Group, Not Discontinued Operation, Gain (Loss) on Disposal	23
FPL[Member]
Gains (losses) related to derivatives not designated as hedging instruments [Abstract]
Gains (losses) on commodity contracts, recorded as regulatory assets and or liabilities on the balance sheet due to regulatory treatment	$ 6	$ 9	$ (31)

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Amount of realized and unrealized gain (loss) of derivative instruments not designated or qualifying as hedging instruments.

+ References

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-Publisher FASB
-Name Accounting Standards Codification
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Amount before tax of gain (loss) recognized on the sale or disposal of a disposal group. Excludes discontinued operations.

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Amount of the cost of borrowed funds accounted for as interest expense.

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