Equity (Earnings Per Share) (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Reconciliation of basic and diluted earnings per share of common stock [Abstract]
Net income (loss) attributable to NEE	$ 680	$ 4,431	[1]
Adjustment for the impact of dilutive securities at NEP	0	(9)
Net income attributable to NEE - assuming dilution	$ 680	$ 4,422
Denominator:
Weighted-average number of common shares outstanding - basic	478.3	470.7	[1]
Equity units, stock options, performance share awards and restricted stock	3.5	3.6
Weighted-average number of common shares outstanding - assuming dilution	481.8	474.3	[1]
Earnings per share attributable to NEE:(a)
Basic (in dollars per share)	$ 1.42	$ 9.41	[1]
Assuming dilution (in dollars per share)	$ 1.41	$ 9.32	[1]
Antidilutive securities (in shares)	0.5	0.2

[1] Amounts have been retrospectively adjusted for an accounting standards update related to leases.