Common Shareholders' Equity (Earnings Per Share) (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Reconciliation of basic and diluted earnings per share of common stock [Abstract]
Net income (loss) attributable to parent	$ 966	$ 753	$ 540	$ 653	$ 507	$ 879	$ 716	$ 650	$ 2,912	$ 2,752	$ 2,465
Denominator:
Weighted-average number of common shares outstanding - basic									463.1	450.5	434.4
Equity units, performance share awards, stock options, forward sale agreement and restricted stock(a)									2.7	3.5	5.7
Weighted-average number of common shares outstanding - assuming dilution									465.8	454.0	440.1
Earnings per share attributable to NEE from continuing operations:
Basic EPS (in dollars per share)									$ 6.29	$ 6.11	$ 5.67
Diluted EPS (in dollars per share)									$ 6.25	$ 6.06	$ 5.60
Antidilutive securities (in shares)									7.9	3.5	2.6