Derivative Instruments (Balance Sheet Disclosure) (Details) - USD ($) $ in Millions	Mar. 31, 2020	Dec. 31, 2019
Derivatives, Fair Value [Line Items]
Derivative assets	$ 2,930	$ 2,386
Derivative Asset, Current	994	762
Derivative Asset, Noncurrent	1,936	1,624
Derivative liability	2,304	1,340
Derivative Liability, Current	448	344
Derivative Liability, Noncurrent	1,856	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	27	2
Non Current Derivative Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Amount Offset Against Collateral	160	139
Noncurrent derivative liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative Liability, Collateral, Right to Reclaim Cash, Offset	113	66
Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative asset, fair value, gross asset	6,427	5,102
Derivative liability, fair value, gross liability	5,727	3,981
Derivative assets	2,930	2,386
Derivative liability	2,304	1,340
Commodity Contract [Member] \| Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative asset, fair value, gross asset	6,367	5,050
Derivative liability, fair value, gross liability	4,103	3,201
Derivative assets	2,900	2,350
Derivative liability	710	576
Interest Rate Contract [Member] \| Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative asset, fair value, gross asset	39	26
Derivative liability, fair value, gross liability	1,517	742
Derivative assets	9	9
Derivative liability	1,487	725
Foreign Exchange Contract [Member] \| Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative asset, fair value, gross asset	21	26
Derivative liability, fair value, gross liability	107	38
Derivative assets	21	27
Derivative liability	107	39
FPL [Member]
Derivatives, Fair Value [Line Items]
Derivative assets	3	3
Derivative liability	15	13
FPL [Member] \| Other Current Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Current	3	3
FPL [Member] \| Other Current Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative Liability, Current	15	12
FPL [Member] \| Other Noncurrent Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative liability		1
FPL [Member] \| Commodity Contract [Member] \| Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative asset, fair value, gross asset	5	4
Derivative liability, fair value, gross liability	17	14
Derivative assets	3	3
Derivative liability	$ 15	$ 13

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