Equity (Earnings Per Share) (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended			9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017		Sep. 30, 2018	Sep. 30, 2017
Reconciliation of basic and diluted earnings per share of common stock [Abstract]
Net income (loss) attributable to NEE	$ 1,007	$ 847	[1]	$ 6,229	$ 3,223	[1]
Adjustment for the impact of dilutive securities at NEP	(4)	0		(33)	0
Net income attributable to NEE - assuming dilution	$ 1,003	$ 847		$ 6,196	$ 3,223
Denominator:
Weighted-average number of common shares outstanding - basic	473.1	469.4	[1]	471.7	468.3	[1]
Equity units, stock options, performance share awards, forward sale agreements and restricted stock	4.3	4.1		3.9	3.7
Weighted-average number of common shares outstanding - assuming dilution	477.4	473.5	[1]	475.6	472.0	[1]
Earnings per share attributable to NEE:
Basic (in dollars per share)	$ 2.13	$ 1.80	[1]	$ 13.21	$ 6.88	[1]
Assuming dilution (in dollars per share)	$ 2.10	$ 1.79	[1]	$ 13.03	$ 6.83	[1]
Antidilutive securities (in shares)				0.2	4.1

[1] Prior period amounts have been retrospectively adjusted as discussed in Note 3 - Amendments to Presentation of Retirement Benefits.