Jointly-Owned Electric Plants (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017
FPL[Member] \| Jointly Owned Nuclear Power Plant 1 [Member]
Proportionate ownership interest In jointly-owned facilities [Abstract]
Facility Name	St. Lucie Unit No. 2
Proportionate ownership share	85.00%
Gross Investment	$ 2,227
Accumulated Depreciation	912
Construction Work in Progress	$ 51
FPL[Member] \| Jointly Owned Power Plant 2 [Member]
Proportionate ownership interest In jointly-owned facilities [Abstract]
Facility Name	Scherer Unit No. 4
Proportionate ownership share	76.00%
Gross Investment	$ 1,222
Accumulated Depreciation	445
Construction Work in Progress	$ 21
NEER [Member] \| Jointly Owned Nuclear Power Plant 2 Member
Proportionate ownership interest In jointly-owned facilities [Abstract]
Facility Name	Duane Arnold
Proportionate ownership share	70.00%	70.00%
Gross Investment	$ 70
Accumulated Depreciation	9
Construction Work in Progress	$ 13
NEER [Member] \| Jointly Owned Nuclear Power Plant 3 [Member]
Proportionate ownership interest In jointly-owned facilities [Abstract]
Facility Name	Seabrook
Proportionate ownership share	88.23%
Gross Investment	$ 1,205
Accumulated Depreciation	337
Construction Work in Progress	$ 85
NEER [Member] \| Jointly Owned Electricity Generation Plant 1 [Member]
Proportionate ownership interest In jointly-owned facilities [Abstract]
Facility Name	Wyman Station Unit No. 4
Proportionate ownership share	87.49%
Gross Investment	$ 28
Accumulated Depreciation	6
Construction Work in Progress	$ 0
NEER [Member] \| Jointly Owned Electricity Generation Plant 2 Member [Domain]
Proportionate ownership interest In jointly-owned facilities [Abstract]
Facility Name	Stanton
Proportionate ownership share	65.00%
Gross Investment	$ 135
Accumulated Depreciation	0
Construction Work in Progress	$ 0
Corporate and Other [Member] \| Jointly Owned Electricity Transmission and Distribution System [Member]
Proportionate ownership interest In jointly-owned facilities [Abstract]
Facility Name	Transmission substation assets located in Seabrook, New Hampshire
Proportionate ownership share	88.23%
Gross Investment	$ 81
Accumulated Depreciation	13
Construction Work in Progress	$ 11

The period end amount owned by the reporting utility of a jointly owned utility plant in service.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 980
-SubTopic 360
-Section S99
-Paragraph 1
-Subparagraph (SAB Topic 10.C)
-URI http://asc.fasb.org/extlink&oid=115995737&loc=d3e659983-123033

+ Details

Name:	us-gaap_JointlyOwnedUtilityPlantGrossOwnershipAmountOfPlantInService
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Identifies the name or location used by the utility of a jointly owned utility plant.

+ References

+ Details

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

- References

No definition available.

+ Details

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

- Definition

The period end amount of construction work in progress at a jointly owned electricity generation plant.

+ References

+ Details

Name:	us-gaap_JointlyOwnedUtilityPlantOwnershipAmountOfConstructionWorkInProgress
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

The period end amount of accumulated depreciation in a jointly owned electricity generation plant.

+ References

+ Details

Name:	us-gaap_JointlyOwnedUtilityPlantOwnershipAmountOfPlantAccumulatedDepreciation
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The proportionate share of interest (percent) in a jointly owned utility plant.

+ References

+ Details

Name:	us-gaap_JointlyOwnedUtilityPlantProportionateOwnershipShare
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Details

Name:	dei_LegalEntityAxis=nee_FloridaPowerLightCompanyMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_JointlyOwnedUtilityPlantAxis=nee_JointlyOwnedNuclearPowerPlant1Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_JointlyOwnedUtilityPlantAxis=nee_JointlyOwnedPowerPlant2Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	dei_LegalEntityAxis=nee_NexteraEnergyResourcesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_JointlyOwnedUtilityPlantAxis=nee_JointlyOwnedNuclearPowerPlant2Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_JointlyOwnedUtilityPlantAxis=nee_JointlyOwnedNuclearPowerPlant3Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_JointlyOwnedUtilityPlantAxis=nee_JointlyOwnedElectricityGenerationPlant1Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_JointlyOwnedUtilityPlantAxis=nee_JointlyOwnedElectricityGenerationPlant2MemberDomain
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	dei_LegalEntityAxis=nee_CorporateandOther1Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_JointlyOwnedUtilityPlantAxis=us-gaap_JointlyOwnedElectricityTransmissionAndDistributionSystemMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: