Common Shareholders' Equity (ESOP) (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Employee Stock Ownership Plan [Abstract]
Defined Contribution Plan, Cost Recognized	$ 63	$ 59	$ 46
ESOP-related unearned compensation at original issue price	1
ESOP-related unearned compensation at closing price as of end of period	$ 11

-- None. No documentation exists for this element. --

No definition available.

Name:	nee_EmployeeStockOwnershipPlanAbstract
Namespace Prefix:	nee_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

The value of ESOP-related unearned compensation included as a reduction of common shareholders' equity, representing unallocated shares at the original issue price.

+ References

No definition available.

+ Details

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Namespace Prefix:	nee_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

The amount of the cost recognized during the period for defined contribution plans.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 70
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=49170846&loc=d3e28014-114942

+ Details

Name:	us-gaap_DefinedContributionPlanCostRecognized
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The fair value of shares held by the ESOP as of the balance sheet date in which no ESOP participant has a vested interest and no lender has a claim. The fair value of an ESOP share is the amount the seller could reasonably expect to receive for it in a current sale between a willing buyer and a willing seller, that is, other than in a forced or liquidation sale, which would be the market price of the stock if it is publicly traded.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 40
-Section 50
-Paragraph 1
-Subparagraph (e)
-URI http://asc.fasb.org/extlink&oid=6418621&loc=d3e17540-113929

+ Details

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Balance Type:	debit
Period Type:	instant