- Definition

Aggregate notional amount of derivative expressed in nonmonetary units. For example, the number of barrels specified in a fuel oil forward purchase contract.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Article 12
-Section 13
-Sentence Column B

+ Details

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Namespace Prefix:	invest_
Data Type:	xbrli:decimalItemType
Balance Type:	na
Period Type:	instant

- Definition

Aggregate notional amount specified by the derivative(s). Expressed as an absolute value.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Article 12
-Section 13
-Sentence Column B

+ Details

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Namespace Prefix:	invest_
Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	instant

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Nominal energy measure used to calculate payments on a derivative instrument.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	num:energyItemType
Balance Type:	na
Period Type:	duration

- Definition

Nominal volume used to calculate payments on a derivative instrument.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	num:volumeItemType
Balance Type:	na
Period Type:	duration

- Details

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Namespace Prefix:
Data Type:	na
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- Details

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Namespace Prefix:
Data Type:	na
Balance Type:
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- Details

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Namespace Prefix:
Data Type:	na
Balance Type:
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- Details

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Namespace Prefix:
Data Type:	na
Balance Type:
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- Details

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Namespace Prefix:
Data Type:	na
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Period Type:

- Details

Name:	us-gaap_DerivativeInstrumentRiskAxis=nee_CommodityContractOilMember
Namespace Prefix:
Data Type:	na
Balance Type:
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- Details

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Namespace Prefix:
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- Details

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- Details

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Namespace Prefix:
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Derivative Instruments (Net Notional Volumes and Additional Disclosures) (Details) bbl in Millions, MWh in Millions, MMBTU in Millions, $ in Millions	6 Months Ended	12 Months Ended
	Jun. 30, 2018 USD ($) MWh MMBTU bbl	Dec. 31, 2017 USD ($) MWh MMBTU bbl	Jul. 25, 2018 USD ($)
Interest Rate Swap [Member]
Derivative [Line Items]
Notional amount	$ 13,000	$ 12,100
Currency Swap [Member]
Derivative [Line Items]
Notional amount	$ 656	$ 718
Short [Member] \| Commodity contract - Power [Member]
Derivative [Line Items]
Non-monetary net notional amount (in MWh) \| MWh	(107)	(109)
Short [Member] \| Commodity contract - Natural gas [Member]
Derivative [Line Items]
Non-monetary net notional amount (in MMBtu) \| MMBTU	110	74
Short [Member] \| Commodity contract - Oil [Member]
Derivative [Line Items]
Non-monetary net notional amount (in barrels) \| bbl	28	15
FPL [Member] \| Short [Member] \| Commodity contract - Power [Member]
Derivative [Line Items]
Non-monetary net notional amount (in MWh) \| MWh	0	0
FPL [Member] \| Short [Member] \| Commodity contract - Oil [Member]
Derivative [Line Items]
Non-monetary net notional amount (in barrels) \| bbl	0	0
FPL [Member] \| Long [Member] \| Commodity contract - Natural gas [Member]
Derivative [Line Items]
Non-monetary net notional amount (in MMBtu) \| MMBTU	375	142
Subsequent Event [Member] \| Interest Rate Swap [Member]
Derivative [Line Items]
Notional amount			$ 3,000