Variable Interest Entities (VIEs) (Details) $ in Millions	1 Months Ended	9 Months Ended		12 Months Ended
	Feb. 28, 2018 USD ($)	Sep. 30, 2018 USD ($) variable_interest_entity entities MW	Sep. 30, 2017 USD ($)	Dec. 31, 2007 USD ($)	Dec. 31, 2017 USD ($) variable_interest_entity
Variable Interest Entity [Line Items]
Total number of consolidated variable interest entities | variable_interest_entity		27
Proceeds from sale of special purpose entity	$ 71
Variable interest entity, gain (loss) on sale of investment, before tax	50
Variable interest entity, gain (loss) on sale of investment, after tax	$ 37
Investment in equity method investees		$ 6,493			$ 2,321
NEP OpCo [Member]
Variable Interest Entity [Line Items]
Total number of consolidated variable interest entities | variable_interest_entity					1
Carrying amount of assets, consolidated variable interest entity					$ 8,400
Carrying amount of liabilities, consolidated variable interest entity					6,200
Other variable interest entities [Member]
Variable Interest Entity [Line Items]
Investments in special purpose entities		2,883			2,634
FPL [Member] | Bankruptcy remote special purpose subsidiary [Member]
Variable Interest Entity [Line Items]
Senior Secured Debt Aggregate Principal Amount Issued				$ 652
Carrying amount of assets, consolidated variable interest entity		73			148
Carrying amount of liabilities, consolidated variable interest entity		75			147
FPL [Member] | Other variable interest entities [Member]
Variable Interest Entity [Line Items]
Investments in special purpose entities		$ 2,390			2,195
NextEra Energy Resources [Member]
Variable Interest Entity [Line Items]
Total number of consolidated variable interest entities | entities		26
NextEra Energy Resources [Member] | Variable Interest Entities Gas And Oil Primary Beneficiary [Member]
Variable Interest Entity [Line Items]
Carrying amount of assets, consolidated variable interest entity		$ 64			89
Carrying amount of liabilities, consolidated variable interest entity		$ 18			29
Natural gas and or oil electric generating facility capacity (in megawatts) | MW		110
NextEra Energy Resources [Member] | Photovoltaic Solar Facility [Member]
Variable Interest Entity [Line Items]
Total number of consolidated variable interest entities | variable_interest_entity		2
Number of entities with ownership interest contributed | entities		3
Solar generating facility capability (in MW) | MW		277
Wind electric generating facility capability (in megawatts) | MW		374
NextEra Energy Resources [Member] | Special Purpose Entity that has Insufficient Equity at Risk [Member]
Variable Interest Entity [Line Items]
Carrying amount of assets, consolidated variable interest entity					490
Carrying amount of liabilities, consolidated variable interest entity					$ 502
NextEra Energy Resources [Member] | Wind variable interest entities [Member]
Variable Interest Entity [Line Items]
Total number of consolidated variable interest entities | variable_interest_entity		23			31
Carrying amount of assets, consolidated variable interest entity		$ 9,500			$ 13,100
Carrying amount of liabilities, consolidated variable interest entity		$ 1,100			6,900
Wind electric generating facility capability (in megawatts) | MW		6,035
NextEra Energy Resources [Member] | Gas and or Oil Variable Interest Entities [Member]
Variable Interest Entity [Line Items]
Total number of consolidated variable interest entities | variable_interest_entity		1
NextEra Energy Partners [Member] | Wind variable interest entities [Member]
Variable Interest Entity [Line Items]
Total number of consolidated variable interest entities | variable_interest_entity		7
Indirect Subsidiary of NextEra Energy Resources [Member] | Photovoltaic Solar Facility [Member]
Variable Interest Entity [Line Items]
Carrying amount of assets, consolidated variable interest entity		$ 549			548
Carrying amount of liabilities, consolidated variable interest entity		$ 554			594
Ownership percentage		50.00%
Subsidiaries of NEE [Member]
Variable Interest Entity [Line Items]
Additional commitments to invest		$ 60	$ 75
Additional VIEs committed to invest in | variable_interest_entity		3
Other Investments [Member]
Variable Interest Entity [Line Items]
Investment in equity method investees		$ 4,782			$ 248
Senior Secured Debt [Member] | FPL [Member] | Bankruptcy remote special purpose subsidiary [Member]
Variable Interest Entity [Line Items]
Proceeds from issuance of storm-recovery bonds				$ 644
NEP OpCo [Member]
Variable Interest Entity [Line Items]
Ownership percentage					65.10%