Summarized Financial Information of NEECH - Cash Flows (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Net cash provided by operating activities	$ 8,155	$ 6,593	$ 6,458
CASH FLOWS FROM INVESTING ACTIVITIES
Capital expenditures, acquisitions, independent power and other investments and nuclear fuel purchases	(17,462)	(13,004)	(10,740)
Capital contributions from NEE	0	0	0
Proceeds from sale of the fiber-optic telecommunications business	0	0	1,454
Sale of independent power and other investments of NEER	1,163	1,617	178
Proceeds from sale or maturity of securities in special use funds and other investments	4,008	3,410	3,207
Purchases of securities in special use funds and other investments	(4,160)	(3,733)	(3,244)
Distributions from equity method investees	0	637	7
Other - net	274	123	220
Net cash used in investing activities	(16,177)	(10,950)	(8,918)
CASH FLOWS FROM FINANCING ACTIVITIES
Issuances of long-term debt	13,919	4,399	8,354
Retirements of long-term debt	(5,492)	(3,102)	(6,780)
Proceeds from differential membership investors	1,604	1,841	1,414
Net change in commercial paper	(234)	1,062	1,419
Proceeds from other short-term debt	200	5,665	450
Repayments of other short-term debt	(4,765)	(455)	(2)
Payments to related parties under CSCS agreement – net	(54)	(21)	0
Issuances of common stock - net	1,494	718	55
Proceeds from issuance of NEP convertible preferred units - net	0	0	548
Dividends on common stock	(2,408)	(2,101)	(1,845)
Contributions from (dividends to) NEE	0	0	0
Other - net	(391)	(372)	(725)
Net cash provided by (used in) financing activities	3,873	7,634	2,888
Effects of currency translation on cash, cash equivalents and restricted cash	4	(7)	26
Net increase (decrease) in cash, cash equivalents and restricted cash	(4,145)	3,270	454
Cash, cash equivalents and restricted cash at beginning of year	5,253	1,983	1,529
Cash, cash equivalents and restricted cash at end of year	1,108	5,253	1,983
Reportable Legal Entities [Member] | NEE (Guarantor) [Member]
Net cash provided by operating activities	2,769	3,401	1,968
CASH FLOWS FROM INVESTING ACTIVITIES
Capital expenditures, acquisitions, independent power and other investments and nuclear fuel purchases	(7)	(132)	0
Capital contributions from NEE	(1,876)	(6,270)	(92)
Proceeds from sale of the fiber-optic telecommunications business	0	0	0
Sale of independent power and other investments of NEER	0	0	0
Proceeds from sale or maturity of securities in special use funds and other investments	0	0	9
Purchases of securities in special use funds and other investments	0	0	0
Distributions from equity method investees	0	4,466	0
Other - net	103	12	7
Net cash used in investing activities	(1,780)	(1,924)	(76)
CASH FLOWS FROM FINANCING ACTIVITIES
Issuances of long-term debt	0	0	0
Retirements of long-term debt	0	0	0
Proceeds from differential membership investors	0	0	0
Net change in commercial paper	0	0	0
Proceeds from other short-term debt	0	0	0
Repayments of other short-term debt	0	0	0
Payments to related parties under CSCS agreement – net	0	0
Issuances of common stock - net	1,494	718	55
Proceeds from issuance of NEP convertible preferred units - net	0	0	0
Dividends on common stock	(2,408)	(2,101)	(1,845)
Contributions from (dividends to) NEE	0	0	0
Other - net	(73)	(96)	(102)
Net cash provided by (used in) financing activities	(987)	(1,479)	(1,892)
Effects of currency translation on cash, cash equivalents and restricted cash	0	0	0
Net increase (decrease) in cash, cash equivalents and restricted cash	2	(2)	0
Cash, cash equivalents and restricted cash at beginning of year	(1)	1	1
Cash, cash equivalents and restricted cash at end of year	1	(1)	1
Reportable Legal Entities [Member] | Non-Guarantor Subsidiaries [Member]
Net cash provided by operating activities	2,562	2,094	2,749
CASH FLOWS FROM INVESTING ACTIVITIES
Capital expenditures, acquisitions, independent power and other investments and nuclear fuel purchases	(6,509)	(7,735)	(5,449)
Capital contributions from NEE	0	0	0
Proceeds from sale of the fiber-optic telecommunications business	0	0	1,454
Sale of independent power and other investments of NEER	1,163	1,617	178
Proceeds from sale or maturity of securities in special use funds and other investments	1,279	1,178	1,221
Purchases of securities in special use funds and other investments	(1,306)	(1,330)	(1,163)
Distributions from equity method investees	0	637	7
Other - net	150	(130)	195
Net cash used in investing activities	(5,223)	(5,763)	(3,557)
CASH FLOWS FROM FINANCING ACTIVITIES
Issuances of long-term debt	10,916	2,651	6,393
Retirements of long-term debt	(5,292)	(1,512)	(5,907)
Proceeds from differential membership investors	1,604	1,841	1,414
Net change in commercial paper	(651)	1,493	0
Proceeds from other short-term debt	0	5,665	0
Repayments of other short-term debt	(4,765)	(205)	0
Payments to related parties under CSCS agreement – net	(54)	(21)
Issuances of common stock - net	0	0	0
Proceeds from issuance of NEP convertible preferred units - net	0	0	548
Dividends on common stock	0	0	0
Contributions from (dividends to) NEE	1,479	(7,272)	(633)
Other - net	(271)	(238)	(601)
Net cash provided by (used in) financing activities	2,966	2,402	1,214
Effects of currency translation on cash, cash equivalents and restricted cash	4	(7)	26
Net increase (decrease) in cash, cash equivalents and restricted cash	309	(1,274)	432
Cash, cash equivalents and restricted cash at beginning of year	533	1,807	1,375
Cash, cash equivalents and restricted cash at end of year	842	533	1,807
Consolidation, Eliminations [Member]
Net cash provided by operating activities	2,824	1,098	1,741
CASH FLOWS FROM INVESTING ACTIVITIES
Capital expenditures, acquisitions, independent power and other investments and nuclear fuel purchases	(10,946)	(5,137)	(5,291)
Capital contributions from NEE	1,876	6,270	92
Proceeds from sale of the fiber-optic telecommunications business	0	0	0
Sale of independent power and other investments of NEER	0	0	0
Proceeds from sale or maturity of securities in special use funds and other investments	2,729	2,232	1,977
Purchases of securities in special use funds and other investments	(2,854)	(2,403)	(2,081)
Distributions from equity method investees	0	(4,466)	0
Other - net	21	241	18
Net cash used in investing activities	(9,174)	(3,263)	(5,285)
CASH FLOWS FROM FINANCING ACTIVITIES
Issuances of long-term debt	3,003	1,748	1,961
Retirements of long-term debt	(200)	(1,590)	(873)
Proceeds from differential membership investors	0	0	0
Net change in commercial paper	417	(431)	1,419
Proceeds from other short-term debt	200	0	450
Repayments of other short-term debt	0	(250)	(2)
Payments to related parties under CSCS agreement – net	0	0
Issuances of common stock - net	0	0	0
Proceeds from issuance of NEP convertible preferred units - net	0	0	0
Dividends on common stock	0	0	0
Contributions from (dividends to) NEE	(1,479)	7,272	633
Other - net	(47)	(38)	(22)
Net cash provided by (used in) financing activities	1,894	6,711	3,566
Effects of currency translation on cash, cash equivalents and restricted cash	0	0	0
Net increase (decrease) in cash, cash equivalents and restricted cash	(4,456)	4,546	22
Cash, cash equivalents and restricted cash at beginning of year	4,721	175	153
Cash, cash equivalents and restricted cash at end of year	$ 265	$ 4,721	$ 175