Segment Information - Schedule of Segment Information (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Segment Reporting Information [Line Items]
Operating revenues	$ 4,010	$ 4,808	$ 4,404	$ 3,972	$ 3,699	$ 4,805	$ 3,817	$ 3,835	$ 17,195	$ 16,155	$ 17,486
Operating expenses - net									11,869	11,547	12,854
Interest expense									1,558	1,093	1,211
Interest income									81	82	86
Depreciation and amortization									2,357	3,077	2,831
Equity in losses (earnings) of equity method investees									141	148	107
Income tax expense (benefit)									(653)	1,383	1,228
Net income (loss)	2,068	856	804	1,591	1,017	789	544	654	5,320	3,005	2,762
Net income (loss) attributable to NEE	2,155	$ 847	$ 793	$ 1,583	966	$ 753	$ 540	$ 653	5,378	2,912	2,752
Capital expenditures, independent power and other investments and nuclear fuel purchases									10,740	9,636	8,377
Property, plant and equipment	93,783				87,013				93,783	87,013	80,330
Accumulated depreciation and amortization	21,367				20,101				21,367	20,101	18,944
Total assets	97,827				89,993				97,827	89,993	82,479
Investment in equity method investees	$ 2,321				1,767				$ 2,321	1,767	1,063
NEER [Member]
Segment Reporting Information [Line Items]
Deemed capital structure of NextEra Energy Resources (in hundredths)	70.00%								70.00%
Operating Segments [Member] | FPL[Member]
Segment Reporting Information [Line Items]
Operating revenues									$ 11,972	10,895	11,651
Operating expenses - net									8,581	7,737	8,674
Interest expense									482	456	445
Interest income									2	2	7
Depreciation and amortization									933	1,651	1,576
Equity in losses (earnings) of equity method investees									0	0	0
Income tax expense (benefit)									1,106	1,051	957
Net income (loss)									1,880	1,727	1,648
Net income (loss) attributable to NEE									1,880	1,727	1,648
Capital expenditures, independent power and other investments and nuclear fuel purchases									5,291	3,934	3,633
Property, plant and equipment	$ 51,982				48,313				51,982	48,313	45,383
Accumulated depreciation and amortization - FPL	12,802				12,304				12,802	12,304	11,862
Total assets	50,244				45,501				50,244	45,501	42,523
Investment in equity method investees	0				0				0	0	0
Operating Segments [Member] | NEER [Member]
Segment Reporting Information [Line Items]
Operating revenues									5,186	4,893	5,444
Operating expenses - net									4,318	3,419	3,865
Interest expense									801	732	625
Interest income									72	34	28
Depreciation and amortization									1,398	1,366	1,183
Equity in losses (earnings) of equity method investees									136	119	103
Income tax expense (benefit)									(2,025)	242	289
Net income (loss)									2,905	1,218	1,102
Net income (loss) attributable to NEE									2,963	1,125	1,092
Capital expenditures, independent power and other investments and nuclear fuel purchases									5,375	5,521	4,661
Property, plant and equipment	40,767				37,644				40,767	37,644	33,340
Accumulated depreciation and amortization	8,452				7,655				8,452	7,655	6,640
Total assets	45,549				41,743				45,549	41,743	37,647
Investment in equity method investees	2,153				1,661				2,153	1,661	983
Corporate, Non-Segment [Member] | Corporate and Other [Member] | Corporate and Other [Member]
Segment Reporting Information [Line Items]
Operating revenues									37	367	391
Operating expenses - net									(1,030)	391	315
Interest expense									275	(95)	141
Interest income									7	46	51
Depreciation and amortization									26	60	72
Equity in losses (earnings) of equity method investees									5	29	4
Income tax expense (benefit)									266	90	(18)
Net income (loss)									535	60	12
Net income (loss) attributable to NEE									535	60	12
Capital expenditures, independent power and other investments and nuclear fuel purchases									74	181	83
Property, plant and equipment	1,034				1,056				1,034	1,056	1,607
Accumulated depreciation and amortization	113				142				113	142	442
Total assets	2,034				2,749				2,034	2,749	2,309
Investment in equity method investees	$ 168				$ 106				$ 168	$ 106	$ 80