Variable Interest Entities (VIEs) (Details) $ in Millions	9 Months Ended	12 Months Ended
	Sep. 30, 2017 USD ($) variable_interest_entity entities MW	Dec. 31, 2016 USD ($) variable_interest_entity	Dec. 31, 2007 USD ($)
Variable Interest Entity [Line Items]
Total number of consolidated variable interest entities | variable_interest_entity	33
Investment in subsidiaries	$ 0	$ 0
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	$ 7,800	7,200
Carrying amount of liabilities, consolidated variable interest entity	5,700	5,000
Other variable interest entities [Member]
Variable Interest Entity [Line Items]
Investments in special purpose entities	2,601	2,505
FPL [Member] | Bankruptcy remote special purpose subsidiary [Member]
Variable Interest Entity [Line Items]
Carrying amount of assets, consolidated variable interest entity	143	216
Carrying amount of liabilities, consolidated variable interest entity	145	214
FPL [Member] | Other variable interest entities [Member]
Variable Interest Entity [Line Items]
Investments in special purpose entities	$ 2,133	2,049
NextEra Energy Resources [Member]
Variable Interest Entity [Line Items]
Total number of consolidated variable interest entities | variable_interest_entity	32
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
Carrying amount of assets, consolidated variable interest entity	$ 83	95
Carrying amount of liabilities, consolidated variable interest entity	$ 28	42
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
Carrying amount of assets, consolidated variable interest entity		571
Carrying amount of liabilities, consolidated variable interest entity		487
Ownership percentage	50.00%
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] | Wind variable interest entities [Member]
Variable Interest Entity [Line Items]
Total number of consolidated variable interest entities | variable_interest_entity	27
Carrying amount of assets, consolidated variable interest entity	$ 10,500	10,900
Carrying amount of liabilities, consolidated variable interest entity	$ 5,900	6,900
Wind electric generating facility capability (in megawatts) | MW	6,649
Indirect Subsidiary of NextEra Energy Resources [Member] | Photovoltaic Solar Facility [Member]
Variable Interest Entity [Line Items]
Carrying amount of assets, consolidated variable interest entity	$ 574
Carrying amount of liabilities, consolidated variable interest entity	481
NEECH [Member] | Special Purpose Entity that has Insufficient Equity at Risk [Member]
Variable Interest Entity [Line Items]
Carrying amount of assets, consolidated variable interest entity	505	502
Carrying amount of liabilities, consolidated variable interest entity	493	511
Subsidiaries of NEE [Member]
Variable Interest Entity [Line Items]
Additional commitments to invest	$ 90	$ 30
Additional VIEs committed to invest in | variable_interest_entity	3	2
Other Investments [Member]
Variable Interest Entity [Line Items]
Investment in subsidiaries	$ 268	$ 234
Senior Secured Debt [Member] | FPL [Member] | Bankruptcy remote special purpose subsidiary [Member]
Variable Interest Entity [Line Items]
Storm-recovery bonds aggregate principal amount issued			$ 652
Proceeds from issuance of storm-recovery bonds			$ 644
NEP OpCo [Member]
Variable Interest Entity [Line Items]
Ownership percentage	65.10%