Equity (Earnings Per Share) (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended			6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017		Jun. 30, 2018	Jun. 30, 2017
Reconciliation of basic and diluted earnings per share of common stock [Abstract]
Net income (loss) attributable to NEE	$ 795	$ 793	[1]	$ 5,223	$ 2,376	[1]
Adjustment for the impact of dilutive securities at NEP	(15)	0		(24)	0
Net income attributable to NEE - assuming dilution	$ 780	$ 793		$ 5,199	$ 2,376
Denominator:
Weighted-average number of common shares outstanding - basic	471.1	467.9	[1]	470.9	467.7	[1]
Equity units, stock options, performance share awards, forward sale agreements and restricted stock	4.1	3.8		3.8	3.3
Weighted-average number of common shares outstanding - assuming dilution	475.2	471.7	[1]	474.7	471.0	[1]
Earnings per share attributable to NEE:
Basic (in dollars per share)	$ 1.69	$ 1.69	[1]	$ 11.09	$ 5.08	[1]
Assuming dilution (in dollars per share)	$ 1.64	$ 1.68	[1]	$ 10.95	$ 5.05	[1]
Antidilutive securities (in shares)	0.3	0.4		0.3	6.2

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