Summarized Financial Information of Capital Holdings (Statement of Cash Flows) (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Condensed Consolidating Statements of Cash Flows
NET CASH PROVIDED BY OPERATING ACTIVITIES	$ 5,160	$ 5,294
CASH FLOWS FROM INVESTING ACTIVITIES
Capital expenditures, independent power and other investments and nuclear fuel purchases	(8,587)	(7,929)
Proceeds from sale of the fiber-optic telecommunications business	1,482	0
Capital contributions from NEE	0	0
Sale of independent power and other investments of NEER	159	395
Proceeds from sale or maturity of securities in special use funds	2,059	2,635
Purchases of securities in special use funds	(2,146)	(2,711)
Proceeds from sales of noncontrolling interests in NEP	0	645
Other - net	198	(18)
Net cash used in investing activities	(6,835)	(6,983)
CASH FLOWS FROM FINANCING ACTIVITIES
Issuances of long-term debt	5,196	4,644
Retirements of long-term debt	(3,892)	(2,654)
Proceeds from differential membership investors	340	328
Net change in commercial paper	1,806	254
Proceeds from other short-term debt	200	500
Repayments of other short-term debt	(2)	(362)
Issuances of common stock - net	36	528
Dividends on common stock	(1,382)	(1,205)
Contributions from (dividends to) NEE	0	0
Other - net	(538)	(234)
Net cash provided by (used in) financing activities	1,764	1,799
Net increase (decrease) in cash and cash equivalents	89	110
Cash and cash equivalents at beginning of period	1,292	571
Cash and cash equivalents at end of period	1,381	681
NextEra Energy (Guarantor) [Member]
CASH FLOWS FROM FINANCING ACTIVITIES
Proceeds from differential membership investors		0
Repayments of other short-term debt		0
Reportable Legal Entities [Member] | NextEra Energy (Guarantor) [Member]
Condensed Consolidating Statements of Cash Flows
NET CASH PROVIDED BY OPERATING ACTIVITIES	1,464	1,164
CASH FLOWS FROM INVESTING ACTIVITIES
Capital expenditures, independent power and other investments and nuclear fuel purchases	0	(1)
Proceeds from sale of the fiber-optic telecommunications business	0	0
Capital contributions from NEE	(46)	(432)
Sale of independent power and other investments of NEER	0	0
Proceeds from sale or maturity of securities in special use funds	0	0
Purchases of securities in special use funds	0	0
Proceeds from sales of noncontrolling interests in NEP	0	0
Other - net	7	0
Net cash used in investing activities	(39)	(433)
CASH FLOWS FROM FINANCING ACTIVITIES
Issuances of long-term debt	0	0
Retirements of long-term debt	0	0
Proceeds from differential membership investors	0
Net change in commercial paper	0	0
Proceeds from other short-term debt	0	0
Repayments of other short-term debt	0
Issuances of common stock - net	36	528
Dividends on common stock	(1,382)	(1,205)
Contributions from (dividends to) NEE	0	0
Other - net	(79)	(54)
Net cash provided by (used in) financing activities	(1,425)	(731)
Net increase (decrease) in cash and cash equivalents	0	0
Cash and cash equivalents at beginning of period	1	0
Cash and cash equivalents at end of period	1	0
Reportable Legal Entities [Member] | NEECH Non-Guarantor Subsidiaries [Member]
Condensed Consolidating Statements of Cash Flows
NET CASH PROVIDED BY OPERATING ACTIVITIES	1,793	1,781
CASH FLOWS FROM INVESTING ACTIVITIES
Capital expenditures, independent power and other investments and nuclear fuel purchases	(4,808)	(4,831)
Proceeds from sale of the fiber-optic telecommunications business	1,482	0
Capital contributions from NEE	0	0
Sale of independent power and other investments of NEER	159	395
Proceeds from sale or maturity of securities in special use funds	819	860
Purchases of securities in special use funds	(827)	(874)
Proceeds from sales of noncontrolling interests in NEP	0	645
Other - net	163	(49)
Net cash used in investing activities	(3,012)	(3,854)
CASH FLOWS FROM FINANCING ACTIVITIES
Issuances of long-term debt	4,995	4,494
Retirements of long-term debt	(3,819)	(2,392)
Proceeds from differential membership investors	340	328
Net change in commercial paper	995	(154)
Proceeds from other short-term debt	0	0
Repayments of other short-term debt	0	(212)
Issuances of common stock - net	0	0
Dividends on common stock	0	0
Contributions from (dividends to) NEE	(722)	294
Other - net	(458)	(197)
Net cash provided by (used in) financing activities	1,331	2,161
Net increase (decrease) in cash and cash equivalents	112	88
Cash and cash equivalents at beginning of period	1,258	546
Cash and cash equivalents at end of period	1,370	634
Consolidation, Eliminations [Member]
Condensed Consolidating Statements of Cash Flows
NET CASH PROVIDED BY OPERATING ACTIVITIES	1,903	2,349
CASH FLOWS FROM INVESTING ACTIVITIES
Capital expenditures, independent power and other investments and nuclear fuel purchases	(3,779)	(3,097)
Proceeds from sale of the fiber-optic telecommunications business	0	0
Capital contributions from NEE	46	432
Sale of independent power and other investments of NEER	0	0
Proceeds from sale or maturity of securities in special use funds	1,240	1,775
Purchases of securities in special use funds	(1,319)	(1,837)
Proceeds from sales of noncontrolling interests in NEP	0	0
Other - net	28	31
Net cash used in investing activities	(3,784)	(2,696)
CASH FLOWS FROM FINANCING ACTIVITIES
Issuances of long-term debt	201	150
Retirements of long-term debt	(73)	(262)
Proceeds from differential membership investors	0	0
Net change in commercial paper	811	408
Proceeds from other short-term debt	200	500
Repayments of other short-term debt	(2)	(150)
Issuances of common stock - net	0	0
Dividends on common stock	0	0
Contributions from (dividends to) NEE	722	(294)
Other - net	(1)	17
Net cash provided by (used in) financing activities	1,858	369
Net increase (decrease) in cash and cash equivalents	(23)	22
Cash and cash equivalents at beginning of period	33	25
Cash and cash equivalents at end of period	$ 10	$ 47