Variable Interest Entities (VIEs) (Details) $ in Millions	1 Months Ended	12 Months Ended
	Feb. 28, 2018 USD ($)	Dec. 31, 2018 USD ($) entities MW	Dec. 31, 2017 USD ($) variable_interest_entity entities		Dec. 31, 2007 USD ($)	Mar. 31, 2019 MW	Dec. 31, 2018 variable_interest_entity	Dec. 31, 2018 entities	Dec. 31, 2016 USD ($)	Aug. 31, 2015 MW
Variable Interest Entity [Line Items]
Total number of consolidated variable interest entities (in entities) | variable_interest_entity							31
Investment in equity method investees		$ 6,748	$ 2,321	[1]					$ 1,767
Proceeds from Sale of Long-term Investments	$ 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
NEP OpCo [Member]
Variable Interest Entity [Line Items]
Total number of consolidated variable interest entities (in 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		2,668	2,634
FPL[Member]
Variable Interest Entity [Line Items]
Total generating facility capacity (mw) | MW										250
FPL[Member] | Bankruptcy remote special purpose subsidiary [Member]
Variable Interest Entity [Line Items]
Storm-recovery bonds aggregate principal amount issued					$ 652
Carrying amount of assets, consolidated variable interest entity		77	148
Carrying amount of liabilities, consolidated variable interest entity		76	147
FPL[Member] | Other variable interest entities [Member]
Variable Interest Entity [Line Items]
Investments in special purpose entities		2,203	2,195
NEER [Member]
Variable Interest Entity [Line Items]
Total number of consolidated variable interest entities (in entities) | entities								30
Investment in equity method investees		6,151	$ 2,129
NEER [Member] | Gas and/or oil variable interest entities [Member]
Variable Interest Entity [Line Items]
Total number of consolidated variable interest entities (in entities) | entities			1					3
Carrying amount of assets, consolidated variable interest entity		257	$ 89
Carrying amount of liabilities, consolidated variable interest entity		$ 21	$ 29
Natural gas and or oil electric generating facility capacity (in megawatts) | MW		1,560
Number of variable interest entities | entities								4
Number of VIEs acquired | entities		2
NEER [Member] | Special Purpose Entity that has Insufficient Equity at Risk [Member]
Variable Interest Entity [Line Items]
Total number of consolidated variable interest entities (in entities) | variable_interest_entity			1
Carrying amount of assets, consolidated variable interest entity			$ 490
Carrying amount of liabilities, consolidated variable interest entity			$ 502
NEER [Member] | Variable Interest Entities Wind and Solar Primary Beneficiary [Member] [Member]
Variable Interest Entity [Line Items]
Total number of consolidated variable interest entities (in entities)			31				25
Carrying amount of assets, consolidated variable interest entity		$ 10,200	$ 13,100
Carrying amount of liabilities, consolidated variable interest entity		$ 1,400	$ 6,900
Wind electric generating facility capability (in megawatts) | MW		6,803
Solar generating facility capability | MW		473
NEP [Member]
Variable Interest Entity [Line Items]
Total number of consolidated variable interest entities (in entities) | entities			12
Indirect Subsidiary of NextEra Energy Resources [Member] | Photovoltaic Solar Facility [Member]
Variable Interest Entity [Line Items]
Total number of consolidated variable interest entities (in entities)							2	2
Carrying amount of assets, consolidated variable interest entity		$ 529	$ 548
Carrying amount of liabilities, consolidated variable interest entity		$ 557	594
Ownership percentage (in hundredths)		50.00%
Number of variable interest entities | entities								3
Solar generating facility capability | MW		277
Subsidiaries of NEE [Member]
Variable Interest Entity [Line Items]
Equity method investments, additional commitments to invest		$ 55	$ 75
Equity method investments, additional variable interest entities committed to invest in | variable_interest_entity			3
NEP OpCo [Member]
Variable Interest Entity [Line Items]
Noncontrolling interest ownership percentage			65.10%						65.20%
Other Investments [Member]
Variable Interest Entity [Line Items]
Investment in equity method investees		$ 4,680	$ 248
Secured Debt [Member] | FPL[Member] | Bankruptcy remote special purpose subsidiary [Member]
Variable Interest Entity [Line Items]
Proceeds from Issuance of Senior Long-term Debt					$ 644
NEP OpCo [Member]
Variable Interest Entity [Line Items]
Noncontrolling interest ownership percentage			65.10%
Scenario, Forecast [Member] | NEER [Member] | Variable Interest Entities Wind and Solar Primary Beneficiary [Member] [Member]
Variable Interest Entity [Line Items]
Total generating facility capacity (mw) | MW						278

[1] Amounts have been retrospectively adjusted as discussed in Note 14.