Common Shareholders' Equity (Earnings Per Share) (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	12 Months Ended
Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Reconciliation of basic and diluted earnings per share of common stock [Abstract]
Income (loss) from continuing operations attributable to parent	$ 2,752	$ 2,465	$ 1,677
Denominator:
Weighted-average number of common shares outstanding - basic (in shares)	450.5	434.4	424.2
Equity units, performance share awards, options, forward sale agreements and restricted stock (in shares)	3.5	5.7	2.8
Weighted-average number of common shares outstanding - assuming dilution (in shares)	454.0	440.1	427.0
Earnings per share attributable to NEE from continuing operations:
Basic EPS (in dollars per share)	$ 6.11	$ 5.67	$ 3.95
Diluted EPS (in dollars per share)	$ 6.06	$ 5.60	$ 3.93
Antidilutive securities (in shares)	3.5	2.6	7.1

Securities (including those issuable pursuant to contingent stock agreements) that could potentially dilute basic earnings per share (EPS) or earnings per unit (EPU) in the future that were not included in the computation of diluted EPS or EPU because to do so would increase EPS or EPU amounts or decrease loss per share or unit amounts for the period presented.

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Amount of income (loss) from continuing operations attributable to the parent. Also defined as revenue less expenses and taxes from ongoing operations before extraordinary items but after deduction of those portions of income or loss from continuing operations that are allocable to noncontrolling interests.

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The amount of net income (loss) from continuing operations per each share of common stock or unit outstanding during the reporting period.

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The amount of net income (loss) derived from continuing operations during the period available to each share of common stock or common unit outstanding during the reporting period and to each share or unit that would have been outstanding assuming the issuance of common shares or units for all dilutive potential common shares or units outstanding during the reporting period.

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The average number of shares or units issued and outstanding that are used in calculating diluted EPS or earnings per unit (EPU), determined based on the timing of issuance of shares or units in the period.

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