Summary of Significant Accounting and Reporting Policies (Details) $ in Millions		3 Months Ended					9 Months Ended
	Jan. 01, 2018 USD ($)	Dec. 31, 2018 USD ($) solar_generation_facility	Dec. 31, 2018 USD ($) wind_generation_facility	Sep. 30, 2018 USD ($) MW	Sep. 30, 2017 USD ($)	[1]	Sep. 30, 2018 USD ($) MW	Sep. 30, 2017 USD ($)		Dec. 31, 2017 USD ($)
Subsidiary, Sale of Stock [Line Items]
Restricted cash and cash equivalents, current				$ 224			$ 224			$ 269
Restricted cash related to margin cash collateral that is netted against derivative instruments				70			70
Net income (loss) attributable to noncontrolling interest				(64)	$ 9		(754)	$ 29	[1]
FPL [Member]
Subsidiary, Sale of Stock [Line Items]
Restricted cash and cash equivalents, current				102			102			141
FPL FiberNet [Member] | Indirect Wholly-Owned Subsidiary [Member]
Subsidiary, Sale of Stock [Line Items]
Proceeds from sale of ownership interest in subsidiary								1,100
Retirement of debt								370
Gain on sale of ownership interest in subsidiary								1,100
Gain on sale of ownership interest in subsidiary after-tax								$ 685
Other Current Assets [Member]
Subsidiary, Sale of Stock [Line Items]
Restricted cash and cash equivalents, current				198			198			247
Other Current Assets [Member] | FPL [Member]
Subsidiary, Sale of Stock [Line Items]
Restricted cash and cash equivalents, current				$ 76			76			$ 128
Accounting Standards Update 2017-05 - Sales of Differential Membership Interests [Member]
Subsidiary, Sale of Stock [Line Items]
Income (loss) attributable to noncontrolling interest, before tax							497
Net income (loss) attributable to noncontrolling interest							$ 373
Retained Earnings [Member] | Accounting Standards Update 2017-05 - Sales of Differential Membership Interests [Member]
Subsidiary, Sale of Stock [Line Items]
Cumulative effect on retained earnings, after tax	$ 34
Cumulative effect on retained earnings, before tax	56
Retained Earnings [Member] | Accounting Standards Update 2017-05 - NEER Sale of Assets to NEP [Member] | NextEra Energy Resources [Member]
Subsidiary, Sale of Stock [Line Items]
Cumulative effect on retained earnings, after tax	(52)
Cumulative effect on retained earnings, before tax	(69)
Additional Paid-in Capital [Member] | Accounting Standards Update 2017-05 - Sales of Differential Membership Interests [Member]
Subsidiary, Sale of Stock [Line Items]
Additional paid in capital	(77)
Additional paid in capital, after tax	(59)
Additional Paid-in Capital [Member] | Accounting Standards Update 2017-05 - NEER Sale of Assets to NEP [Member] | NextEra Energy Resources [Member]
Subsidiary, Sale of Stock [Line Items]
Additional paid in capital	842
Additional paid in capital, after tax	$ 652
Assets Held for Sale [Member] | NextEra Energy Resources [Member]
Subsidiary, Sale of Stock [Line Items]
Generating capacity (MW) | MW				1,388			1,388
Liabilities associated with assets held for sale				$ 80			$ 80
Scenario, Forecast [Member] | Assets Held for Sale [Member] | NextEra Energy Resources [Member]
Subsidiary, Sale of Stock [Line Items]
Number of generation facilities purchased		1	10
Purchase price		$ 1,300	$ 1,300
Existing noncontrolling interests		$ 930	$ 930

[1] Prior period amounts have been retrospectively adjusted as discussed in Note 3 - Amendments to Presentation of Retirement Benefits.