Equity (Earnings Per Share) (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Reconciliation of basic and diluted earnings per share of common stock [Abstract]
Net income (loss) attributable to NEE									$ 2,919	$ 3,769	$ 6,638
Dilutive Securities, Effect on Basic Earnings Per Share									0	0	(19)
Net Income (Loss) Attributable to Parent, Diluted									$ 2,919	$ 3,769	$ 6,619
Denominator:
Weighted-average number of common shares outstanding - basic									1,959.0	1,927.9	1,892.8
Equity units, stock options, performance share awards, forward sale agreements and restricted stock									9.8	14.0	15.1
Weighted-average number of common shares outstanding - assuming dilution									1,968.8	1,941.9	1,907.9
Earnings per share attributable to NEE:
Basic	$ 0	$ 0.63	$ 0.65	$ 0.21	$ 0.50	$ 0.46	$ 0.64	$ 0.36	$ 1.49	$ 1.95	$ 3.51
Assuming dilution	$ 0	$ 0.62	$ 0.65	$ 0.21	$ 0.50	$ 0.45	$ 0.64	$ 0.35	$ 1.48	$ 1.94	$ 3.47
Antidilutive securities (in shares)									27.1	3.0	0.5