Summarized Financial Information of NEECH - Cash Flows (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Net cash provided by operating activities	$ 6,116	$ 5,500	$ 5,102
CASH FLOWS FROM INVESTING ACTIVITIES
Capital expenditures, independent power and other investments and nuclear fuel purchases	(8,377)	(7,017)	(6,682)
Capital contributions from NEE	0	0	0
Cash grants under the Recovery Act	8	343	165
Sale of independent power and other investments of NEER	52	307	165
Change in loan proceeds restricted for construction	(9)	(40)	228
Proceeds from the sale of a noncontrolling interest in subsidiaries	345	438	0
Other - net	(24)	(392)	1
Net cash used in investing activities	(8,005)	(6,361)	(6,123)
CASH FLOWS FROM FINANCING ACTIVITIES
Issuances of long-term debt	5,772	5,054	4,371
Retirements of long-term debt	(3,972)	(4,750)	(2,396)
Proceeds from differential membership investors	761	978	448
Issuances of notes payable	1,225	500	0
Retirements of notes payable	(813)	(500)	(200)
Net change in commercial paper	(768)	451	(520)
Issuances of common stock - net	1,298	633	842
Dividends on common stock	(1,385)	(1,261)	(1,122)
Dividends to NEE	0	0	0
Other - net	(235)	(105)	(293)
Net cash provided by (used in) financing activities	1,883	1,000	1,130
Net increase (decrease) in cash and cash equivalents	(6)	139	109
Cash and cash equivalents at beginning of year	577	438	329
Cash and cash equivalents at end of year	571	577	438
NEE (Guarantor) [Member]
Net cash provided by operating activities	1,659	1,615	1,147
CASH FLOWS FROM INVESTING ACTIVITIES
Capital expenditures, independent power and other investments and nuclear fuel purchases	0	(1)	0
Capital contributions from NEE	(1,480)	(912)	(777)
Cash grants under the Recovery Act	0	0	0
Sale of independent power and other investments of NEER	0	0	0
Change in loan proceeds restricted for construction	0	0	0
Proceeds from the sale of a noncontrolling interest in subsidiaries	0	0	0
Other - net	0	10	0
Net cash used in investing activities	(1,480)	(903)	(777)
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
Issuances of notes payable	0	0	0
Retirements of notes payable	0	0	0
Net change in commercial paper	0	0	0
Issuances of common stock - net	1,298	633	842
Dividends on common stock	(1,385)	(1,261)	(1,122)
Dividends to NEE	0	0	0
Other - net	(92)	(84)	(92)
Net cash provided by (used in) financing activities	(179)	(712)	(372)
Net increase (decrease) in cash and cash equivalents	0	0	(2)
Cash and cash equivalents at beginning of year	0	0	2
Cash and cash equivalents at end of year	0	0	0
NEECH [Member]
Net cash provided by operating activities	2,488	1,976	1,466
CASH FLOWS FROM INVESTING ACTIVITIES
Capital expenditures, independent power and other investments and nuclear fuel purchases	(4,744)	(3,741)	(3,756)
Capital contributions from NEE	0	0	0
Cash grants under the Recovery Act	8	343	165
Sale of independent power and other investments of NEER	52	307	165
Change in loan proceeds restricted for construction	27	(40)	228
Proceeds from the sale of a noncontrolling interest in subsidiaries	345	438	0
Other - net	9	(73)	17
Net cash used in investing activities	(4,303)	(2,766)	(3,181)
CASH FLOWS FROM FINANCING ACTIVITIES
Issuances of long-term debt	4,689	4,057	3,874
Retirements of long-term debt	(3,421)	(4,395)	(1,943)
Proceeds from differential membership investors	761	978	448
Issuances of notes payable	1,125	500	0
Retirements of notes payable	(813)	(500)	(200)
Net change in commercial paper	318	(487)	(619)
Issuances of common stock - net	0	0	0
Dividends on common stock	0	0	0
Dividends to NEE	(698)	812	502
Other - net	(162)	(31)	(216)
Net cash provided by (used in) financing activities	1,799	934	1,846
Net increase (decrease) in cash and cash equivalents	(16)	144	131
Cash and cash equivalents at beginning of year	562	418	287
Cash and cash equivalents at end of year	546	562	418
Other [Member]
Net cash provided by operating activities	1,969	1,909	2,489
CASH FLOWS FROM INVESTING ACTIVITIES
Capital expenditures, independent power and other investments and nuclear fuel purchases	(3,633)	(3,275)	(2,926)
Capital contributions from NEE	1,480	912	777
Cash grants under the Recovery Act	0	0	0
Sale of independent power and other investments of NEER	0	0	0
Change in loan proceeds restricted for construction	(36)	0	0
Proceeds from the sale of a noncontrolling interest in subsidiaries	0	0	0
Other - net	(33)	(329)	(16)
Net cash used in investing activities	(2,222)	(2,692)	(2,165)
CASH FLOWS FROM FINANCING ACTIVITIES
Issuances of long-term debt	1,083	997	497
Retirements of long-term debt	(551)	(355)	(453)
Proceeds from differential membership investors	0	0	0
Issuances of notes payable	100	0	0
Retirements of notes payable	0	0	0
Net change in commercial paper	(1,086)	938	99
Issuances of common stock - net	0	0	0
Dividends on common stock	0	0	0
Dividends to NEE	698	(812)	(502)
Other - net	19	10	15
Net cash provided by (used in) financing activities	263	778	(344)
Net increase (decrease) in cash and cash equivalents	10	(5)	(20)
Cash and cash equivalents at beginning of year	15	20	40
Cash and cash equivalents at end of year	$ 25	$ 15	$ 20