Equity (Earnings Per Share) (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Reconciliation of basic and diluted earnings per share of common stock [Abstract]
Net income (loss) attributable to NEE	$ 975	$ 879	$ 1,234	$ 680	$ 422	$ 1,005	$ 781	$ 4,431	$ 3,769	$ 6,638	$ 5,380
Dilutive Securities, Effect on Basic Earnings Per Share									0	(19)	0
Net Income (Loss) Attributable to Parent, Diluted									$ 3,769	$ 6,619	$ 5,380
Denominator:
Weighted-average number of common shares outstanding - basic									482.0	473.2	468.8
Equity units, stock options, performance share awards, forward sale agreements and restricted stock									3.5	3.8	3.7
Weighted-average number of common shares outstanding - assuming dilution									485.5	477.0	472.5
Earnings per share attributable to NEE:
Basic	$ 2.00	$ 1.82	$ 2.58	$ 1.42	$ 0.88	$ 2.12	$ 1.66	$ 9.41	$ 7.82	$ 14.03	$ 11.48
Assuming dilution	$ 1.99	$ 1.81	$ 2.56	$ 1.41	$ 0.88	$ 2.10	$ 1.61	$ 9.32	$ 7.76	$ 13.88	$ 11.39
Antidilutive securities (in shares)									0.7	0.1	3.1