marketable securities, unrealized gain (loss) recognized during the period on securities still held

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- Definition

This item represents the weighted-average maturity of debt securities (in years) in nuclear decommissioning funds at the balance sheet date and which are categorized neither as held-to-maturity nor trading securities.

+ References

No definition available.

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- Definition

Storm fund assets held by a regulated entity to pay for storm-related costs as incurred in future periods.

+ References

No definition available.

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- Definition

Amount, before tax, of unrealized gain in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=118939692&loc=d3e27161-111563

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- Definition

Amount, before tax, of unrealized loss in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)
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- Definition

Amortized cost of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)
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-Topic 326
-SubTopic 30
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=118942338&loc=SL82898722-210454

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- Definition

This item represents the aggregate fair value of investments in debt and equity securities in an unrealized loss position which are categorized neither as held-to-maturity nor trading securities.

+ References

No definition available.

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- Definition

This item represents the gross profit realized on the sale of debt or equity securities categorized neither as held-to-maturity nor trading securities.

+ References

No definition available.

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- Definition

This item represents the gross loss realized on the sale of debt or equity securities categorized neither as held-to-maturity nor trading securities.

+ References

No definition available.

+ Details

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- Definition

Period between issuance and maturity of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (bbb)(2)
-URI http://asc.fasb.org/extlink&oid=117815213&loc=d3e19207-110258

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- Definition

The fair value of investments held in a trust fund to pay for the costs of decontaminating and decommissioning facilities, whether such amount is presented as a separate caption or as a parenthetical disclosure on the balance sheet. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 410
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=6392692&loc=d3e7535-110849

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- Definition

Amount of cash inflow from sale of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
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-SubTopic 10
-Section 45
-Paragraph 12
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=118932676&loc=d3e3179-108585

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

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Fair Value Measurements (Available for Sale Securities) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Schedule of Available-for-sale Securities[Line Items]
Decommissioning Fund Investments, Fair Value	$ 6,880	$ 5,818
Debt Securities, Available-for-sale, Amortized Cost	$ 2,030	1,994
Special Use Funds Nuclear Decommissioning Funds Weighted Average Maturity	8 years
Debt Securities [Member]
Schedule of Available-for-sale Securities[Line Items]
Realized gains	$ 68	51
Realized losses	48	75
Proceeds from sale and maturity of Available-for-sale Securities	3,005	2,551
debt and equity securities [Member]
Schedule of Available-for-sale Securities[Line Items]
Realized gains			$ 178
Realized losses			83
Proceeds from sale and maturity of Available-for-sale Securities			2,817
Available for sale securities: Special Use Funds - Debt Securities [Member]
Schedule of Available-for-sale Securities[Line Items]
Unrealized gains	75	14
Unrealized losses	7	52
Fair Value	314	1,273
FPL[Member]
Schedule of Available-for-sale Securities[Line Items]
Decommissioning Fund Investments, Fair Value	4,697	3,987
Special Use Funds Storm Fund Assets	74	68
Debt Securities, Available-for-sale, Amortized Cost	1,523	1,542
FPL[Member] \| Debt Securities [Member]
Schedule of Available-for-sale Securities[Line Items]
Realized gains	44	31
Realized losses	29	49
Proceeds from sale and maturity of Available-for-sale Securities	2,539	2,100
FPL[Member] \| debt and equity securities [Member]
Schedule of Available-for-sale Securities[Line Items]
Realized gains			75
Realized losses			50
Proceeds from sale and maturity of Available-for-sale Securities			$ 1,902
FPL[Member] \| Available for sale securities: Special Use Funds - Debt Securities [Member]
Schedule of Available-for-sale Securities[Line Items]
Unrealized gains	58	11
Unrealized losses	7	41
Fair Value	$ 240	961
Debt Securities [Member] \| Storm Fund [Member]
Schedule of Available-for-sale Securities[Line Items]
Debt Securities, Available-for-sale, Term	1 year
Debt Securities [Member] \| FPL[Member] \| Storm Fund [Member]
Schedule of Available-for-sale Securities[Line Items]
Debt Securities, Available-for-sale, Term	1 year
Equity Securities [Member]
Schedule of Available-for-sale Securities[Line Items]
marketable securities, unrealized gain (loss) recognized during the period on securities still held	$ 780	(259)
Equity Securities [Member] \| FPL[Member]
Schedule of Available-for-sale Securities[Line Items]
marketable securities, unrealized gain (loss) recognized during the period on securities still held	$ 510	$ (131)
Weighted Average [Member] \| Nuclear Decommissioning Funds [Member]
Schedule of Available-for-sale Securities[Line Items]
Debt Securities, Available-for-sale, Term	8 years
Weighted Average [Member] \| FPL[Member] \| Nuclear Decommissioning Funds [Member]
Schedule of Available-for-sale Securities[Line Items]
Debt Securities, Available-for-sale, Term	8 years
Weighted Average [Member] \| FPL[Member] \| Storm Fund [Member]
Schedule of Available-for-sale Securities[Line Items]
Debt Securities, Available-for-sale, Term	1 year