Derivative Instruments (Balance Sheet Disclosure) (Details) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Derivatives, Fair Value [Line Items]
Derivative assets	$ 2,063	$ 2,386
Derivative Asset, Current	441	762
Derivative Asset, Noncurrent	1,622	1,624
Derivative liability	1,890	1,340
Derivative Liability, Current	310	344
Derivative Liability, Noncurrent	1,580	863
Other Current Liabilities [Member]
Derivatives, Fair Value [Line Items]
Liabilities Associated with Assets Held-for-Sale		133
Current derivative assets [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Amount Offset Against Collateral		2
Non Current Derivative Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Amount Offset Against Collateral	158	139
Current derivative liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative Liability, Collateral, Right to Reclaim Cash, Offset	14	66
Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative asset, fair value, gross asset	4,483	5,102
Derivative liability, fair value, gross liability	4,166	3,981
Derivative assets	2,063	2,386
Derivative liability	1,890	1,340
Commodity Contract [Member] \| Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative asset, fair value, gross asset	4,435	5,050
Derivative liability, fair value, gross liability	2,795	3,201
Derivative assets	2,039	2,350
Derivative liability	543	576
Interest Rate Contract [Member] \| Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative asset, fair value, gross asset	33	26
Derivative liability, fair value, gross liability	1,324	742
Derivative assets	5	9
Derivative liability	1,296	725
Foreign Exchange Contract [Member] \| Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative asset, fair value, gross asset	15	26
Derivative liability, fair value, gross liability	47	38
Derivative assets	19	27
Derivative liability	51	39
FPL [Member]
Derivatives, Fair Value [Line Items]
Derivative assets	2	3
Derivative liability	11	13
FPL [Member] \| Other Current Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Current	2	3
FPL [Member] \| Other Current Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative Liability, Current	10	12
FPL [Member] \| Other Noncurrent Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative Liability, Noncurrent	1	1
FPL [Member] \| Commodity Contract [Member] \| Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative asset, fair value, gross asset	4	4
Derivative liability, fair value, gross liability	13	14
Derivative assets	2	3
Derivative liability	$ 11	$ 13

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