Equity (Earnings Per Share) (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Reconciliation of basic and diluted earnings per share of common stock [Abstract]
Net income (loss) attributable to NEE	$ 847	$ 753	$ 3,223	$ 1,946
Denominator:
Weighted-average number of common shares outstanding - basic	469.4	463.3	468.3	461.7
Equity units, stock options, performance share awards, forward sale agreements and restricted stock	4.1	2.7	3.7	3.0
Weighted-average number of common shares outstanding - assuming dilution	473.5	466.0	472.0	464.7
Earnings per share attributable to NEE:
Basic (in dollars per share)	$ 1.80	$ 1.63	$ 6.88	$ 4.21
Assuming dilution (in dollars per share)	$ 1.79	$ 1.62	$ 6.83	$ 4.19
Antidilutive securities (in shares)	1.0	11.2	4.1	3.9