Common Shareholders' Equity (Earnings Per Share) (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Reconciliation of basic and diluted earnings per share of common stock [Abstract]
Net income (loss) attributable to NEE	$ 879	$ 660	$ 2,245	$ 1,581
Denominator:
Weighted-average number of common shares outstanding - basic	454.1	434.5	447.3	434.0
Equity units, performance share awards, options, forward sale agreement and restricted stock	1.9	6.0	4.0	5.6
Weighted-average number of common shares outstanding - assuming dilution	456.0	440.5	451.3	439.6
Earnings per share attributable to NEE:
Basic (in dollars per share)	$ 1.94	$ 1.52	$ 5.02	$ 3.64
Assuming dilution (in dollars per share)	$ 1.93	$ 1.50	$ 4.97	$ 3.60
Antidilutive securities (in shares)	8.1	5.4	4.6	1.9