For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.

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Amount of the cumulative effect on retained earnings net of related income tax effect.

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Amount, including tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value-added and excise.

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Amount of transaction price allocated to performance obligation that has not been recognized as revenue.

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Unbilled amounts due for services rendered or to be rendered, actions taken or to be taken, or a promise to refrain from taking certain actions in accordance with the terms of a legally binding agreement between the entity and, at a minimum, one other party. An example would be amounts associated with contracts or programs where the recognized revenue for performance thereunder exceeds the amounts billed under the terms thereof as of the date of the balance sheet.

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Revenue from Contracts with Customers (Details) - USD ($) $ in Millions		12 Months Ended
	Jan. 01, 2018	Dec. 31, 2018	Dec. 31, 2017
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contracts with customers		$ 15,400
FPL [Member]
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contracts with customers		11,800
Unbilled revenues		$ 432	$ 428
FPL [Member] \| Sales Revenue, Net [Member]
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Concentration risk, percentage		90.00%
NEER [Member]
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue, remaining performance obligation		$ 860
Accounting Standards Update 2014-09 [Member] \| Retained Earnings [Member]
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net reduction to retained earnings	$ 25