Derivative Instruments (Balance Sheet Disclosure) (Details) - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015
Derivative Instruments and Hedging Activities Disclosures [Abstract]
Derivative Assets	$ 2,235	$ 1,971
Derivative Liabilities	881	1,428
Current derivative assets [Member]
Derivative Instruments and Hedging Activities Disclosures [Abstract]
Derivative Assets	885	712
Margin cash collateral received from counterparties	96	279
Long Lived Assets Held-for-sale, Name [Domain]
Derivative Instruments and Hedging Activities Disclosures [Abstract]
Derivative Assets		57
Non Current Derivative Assets Member [Member]
Derivative Instruments and Hedging Activities Disclosures [Abstract]
Derivative Assets	1,350	1,202
Margin cash collateral received from counterparties	71	151
Current derivative liabilities [Member]
Derivative Instruments and Hedging Activities Disclosures [Abstract]
Derivative Liabilities	404	882
Margin cash collateral paid to counterparties		46
liabilities associated with assets held-for-sale [Member]
Derivative Instruments and Hedging Activities Disclosures [Abstract]
Derivative Liabilities		16
Noncurrent derivative liabilities [Member]
Derivative Instruments and Hedging Activities Disclosures [Abstract]
Derivative Liabilities	477	530
Margin cash collateral paid to counterparties		13
Interest Rate Contract [Member]
Derivative Instruments and Hedging Activities Disclosures [Abstract]
Derivative Assets		34
Derivative Liabilities		319
Foreign currency contracts [Member]
Derivative Instruments and Hedging Activities Disclosures [Abstract]
Derivative Assets		0
Derivative Liabilities		127
Designated as Hedging Instrument [Member]
Derivative Instruments and Hedging Activities Disclosures [Abstract]
Derivative Asset, Fair Value, Gross Asset		33
Derivative Liability, Fair Value, Gross Liability		287
Designated as Hedging Instrument [Member] \| Commodity contracts [Member]
Derivative Instruments and Hedging Activities Disclosures [Abstract]
Derivative Asset, Fair Value, Gross Asset		0
Derivative Liability, Fair Value, Gross Liability		0
Designated as Hedging Instrument [Member] \| Interest Rate Contract [Member]
Derivative Instruments and Hedging Activities Disclosures [Abstract]
Derivative Asset, Fair Value, Gross Asset		33
Derivative Liability, Fair Value, Gross Liability		155
Designated as Hedging Instrument [Member] \| Foreign currency contracts [Member]
Derivative Instruments and Hedging Activities Disclosures [Abstract]
Derivative Asset, Fair Value, Gross Asset		0
Derivative Liability, Fair Value, Gross Liability		132
Not Designated as Hedging Instrument [Member]
Derivative Instruments and Hedging Activities Disclosures [Abstract]
Derivative Asset, Fair Value, Gross Asset	4,879	5,908
Derivative Liability, Fair Value, Gross Liability	3,358	4,740
Derivative Assets	2,235
Derivative Liabilities	881
Not Designated as Hedging Instrument [Member] \| Commodity contracts [Member]
Derivative Instruments and Hedging Activities Disclosures [Abstract]
Derivative Asset, Fair Value, Gross Asset	4,590	5,906
Derivative Liability, Fair Value, Gross Liability	2,968	4,580
Derivative Assets	1,938	1,937
Derivative Liabilities	483	982
Not Designated as Hedging Instrument [Member] \| Interest Rate Contract [Member]
Derivative Instruments and Hedging Activities Disclosures [Abstract]
Derivative Asset, Fair Value, Gross Asset	288	2
Derivative Liability, Fair Value, Gross Liability	284	160
Derivative Assets	296
Derivative Liabilities	292
Not Designated as Hedging Instrument [Member] \| Foreign currency contracts [Member]
Derivative Instruments and Hedging Activities Disclosures [Abstract]
Derivative Asset, Fair Value, Gross Asset	1	0
Derivative Liability, Fair Value, Gross Liability	106	0
Derivative Assets	1
Derivative Liabilities	106
FPL [Member]
Derivative Instruments and Hedging Activities Disclosures [Abstract]
Derivative Assets	209	4
Derivative Liabilities	1	222
FPL [Member] \| Current derivative assets [Member]
Derivative Instruments and Hedging Activities Disclosures [Abstract]
Derivative Assets	209	3
FPL [Member] \| Current derivative liabilities [Member]
Derivative Instruments and Hedging Activities Disclosures [Abstract]
Derivative Liabilities	1	222
FPL [Member] \| Other Noncurrent Assets [Member]
Derivative Instruments and Hedging Activities Disclosures [Abstract]
Derivative Assets		1
FPL [Member] \| Commodity contracts [Member]
Derivative Instruments and Hedging Activities Disclosures [Abstract]
Derivative Asset, Fair Value, Gross Asset
FPL [Member] \| Designated as Hedging Instrument [Member] \| Commodity contracts [Member]
Derivative Instruments and Hedging Activities Disclosures [Abstract]
Derivative Asset, Fair Value, Gross Asset		0
Derivative Liability, Fair Value, Gross Liability		0
FPL [Member] \| Not Designated as Hedging Instrument [Member] \| Commodity contracts [Member]
Derivative Instruments and Hedging Activities Disclosures [Abstract]
Derivative Asset, Fair Value, Gross Asset	212	7
Derivative Liability, Fair Value, Gross Liability	4	225
Derivative Assets	209	4
Derivative Liabilities	$ 1	$ 222

Fair value, after the effects of master netting arrangements, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes assets not subject to a master netting arrangement and not elected to be offset.

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-Publisher FASB
-Name Accounting Standards Codification
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Fair value, after effects of master netting arrangements, of financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset offset against an obligation to return collateral. Includes assets not subject to a master netting arrangement and not elected to be offset.

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Fair value, before effects of master netting arrangements, of a financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes liabilities elected not to be offset. Excludes liabilities not subject to a master netting arrangement.

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