Summary of Significant Accounting and Reporting Policies (Details) $ / shares in Units, $ in Millions		3 Months Ended			9 Months Ended		12 Months Ended
		Dec. 31, 2017 $ / MWh	Sep. 30, 2017 USD ($) $ / shares	Sep. 30, 2016 USD ($)	Sep. 30, 2017 USD ($) $ / shares	Sep. 30, 2016 USD ($)	Dec. 31, 2017 USD ($)	Dec. 31, 2020 USD ($)
Subsidiary, Sale of Stock [Line Items]
Net income (loss) attributable to NEE			$ 847	$ 753	$ 3,223	$ 1,946
FPL [Member]
Subsidiary, Sale of Stock [Line Items]
Net income (loss) attributable to NEE	[1]		566	$ 515	1,537	1,356
Storm restoration costs recoverable, estimated costs			1,300		1,300
Merchant Natural Gas Generation Facilities [Member] | NextEra Energy Resources [Member]
Subsidiary, Sale of Stock [Line Items]
Proceeds from sale of ownership interest in merchant natural gas generation facilities						456
Gain on sale of ownership interest in merchant natural gas generation facilities						254
Gain on sale of ownership interest in merchant natural gas facilities after-tax						$ 106
FPL FiberNet [Member] | Indirect Wholly-Owned Subsidiary [Member]
Subsidiary, Sale of Stock [Line Items]
Proceeds from sale of ownership interest in merchant natural gas generation facilities					1,100
Retirement of debt					370
Gain on sale of ownership interest in merchant natural gas generation facilities					1,100
Gain on sale of ownership interest in merchant natural gas facilities after-tax					$ 685
Minimum [Member] | wind, natural gas and solar plants [Member] | NextEra Energy Resources [Member]
Subsidiary, Sale of Stock [Line Items]
Useful life					30 years
Maximum [Member] | wind, natural gas and solar plants [Member] | NextEra Energy Resources [Member]
Subsidiary, Sale of Stock [Line Items]
Useful life					35 years
Service Life [Member]
Subsidiary, Sale of Stock [Line Items]
Net income (loss) attributable to NEE			$ 15		$ 45
Basic and diluted earnings per share (in dollars per share) | $ / shares			$ 0.03		$ 0.09
Scenario, Forecast [Member] | Service Life [Member]
Subsidiary, Sale of Stock [Line Items]
Net income (loss) attributable to NEE							$ 60
Other Current Liabilities [Member] | FPL [Member]
Subsidiary, Sale of Stock [Line Items]
Accrued storm restoration costs			$ 1,200		$ 1,200
Storm Restoration Costs [Member] | FPL [Member]
Subsidiary, Sale of Stock [Line Items]
Regulatory asset			$ 1,100		$ 1,100
Storm Restoration Costs [Member] | Scenario, Forecast [Member] | FPL [Member]
Subsidiary, Sale of Stock [Line Items]
Rate surcharge request (in dollars per MWh) | $ / MWh		4
Storm reserve								$ 112

[1] FPL's comprehensive income is the same as reported net income.