Equity (Earnings Per Share) (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017		Dec. 31, 2016
Reconciliation of basic and diluted earnings per share of common stock [Abstract]
Net income (loss) attributable to NEE	$ 422	$ 1,005	$ 781	$ 4,431	$ 2,158	$ 846	$ 793	$ 1,583	$ 6,638	$ 5,380	[1]	$ 2,906	[1]
Denominator:
Weighted-average number of common shares outstanding - basic									473.2	468.8	[1]	463.1	[1]
Equity units, stock options, performance share awards, forward sale agreements and restricted stock									3.8	3.7		2.7
Weighted-average number of common shares outstanding - assuming dilution									477.0	472.5	[1]	465.8	[1]
Earnings per share attributable to NEE:
Basic	$ 0.88	$ 2.12	$ 1.66	$ 9.41	$ 4.59	$ 1.80	$ 1.70	$ 3.39	$ 14.03	$ 11.48	[1]	$ 6.27	[1]
Assuming dilution	$ 0.88	$ 2.10	$ 1.61	$ 9.32	$ 4.55	$ 1.79	$ 1.68	$ 3.37	$ 13.88	$ 11.39	[1]	$ 6.24	[1]
Dilutive Securities, Effect on Basic Earnings Per Share									$ (19)	$ 0		$ 0
Net Income (Loss) Attributable to Parent, Diluted									$ 6,619	$ 5,380		$ 2,906
Antidilutive securities (in shares)									0.1	3.1		7.9

[1] Amounts have been retrospectively adjusted as discussed in Note 14 and Note 3 - Amendments to Presentation of Retirement Benefits.