marketable securities, unrealized gain (loss) 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

This item represents the weighted-average maturity of debt securities (in years) held by a regulated entity in the storm fund 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

For FPL, the amount of storm funded included in special use funds on Consolidated Balance Sheets.

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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

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 6
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=82897076&loc=d3e27290-111563

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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

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 9
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=82897076&loc=d3e27357-111563

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- Definition

The total amount of proceeds received for the sale of securities, categorized neither as held-to-maturity nor trading securities, during the reporting period.

+ References

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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.

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- Definition

Amount of unrealized gain before deducting unrealized loss on investments in debt and equity securities classified as available-for-sale securities.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=82897076&loc=d3e27161-111563

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- Definition

Amount of unrealized loss before deducting unrealized gain on investments in available-for-sale securities.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=82897076&loc=d3e27161-111563

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- Definition

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

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
-Paragraph 9
-URI http://asc.fasb.org/extlink&oid=64853466&loc=d3e22663-107794

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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	1 Months Ended	3 Months Ended		6 Months Ended		12 Months Ended
	Jan. 31, 2018	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017
Schedule of Available-for-sale Securities [Line Items]
Fair Value Assumptions, Expected Term				9 years
Special Use Funds Storm Fund Weighted Average Maturity				1 year
Realized Gains			$ 22		$ 76
Realized Losses			14		43
Proceeds from sale or maturity of securities				$ 1,313	1,253
Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Realized Gains		$ 20		28
Realized Losses		26		40
Proceeds from sale or maturity of securities		719	627
Available for sale securities: Special Use Funds - Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Unrealized gains				11		$ 37
Available-for-sale Securities, Gross Unrealized Loss				42		12
Fair value of available for sale securities in an unrealized loss position		1,426		$ 1,426		918
FPL [Member]
Schedule of Available-for-sale Securities [Line Items]
Fair Value Assumptions, Expected Term				9 years
Special Use Funds Storm Fund Weighted Average Maturity				1 year
Realized Gains			13		26
Realized Losses			7		26
Proceeds from sale or maturity of securities			$ 395		$ 836
Storm Fund Included In Special Use Funds		78		$ 78
FPL [Member] \| Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Realized Gains		15		20
Realized Losses		20		29
Proceeds from sale or maturity of securities		653		1,042
FPL [Member] \| Available for sale securities: Special Use Funds - Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Unrealized gains				9		28
Available-for-sale Securities, Gross Unrealized Loss				33		9
Fair value of available for sale securities in an unrealized loss position		1,104		1,104		$ 670
AOCI Including Portion Attributable to Noncontrolling Interest [Member] \| Accounting Standards Update 2016-01 [Member]
Schedule of Available-for-sale Securities [Line Items]
Cumulative Effect on Retained Earnings, Net of Tax	$ (312)
Equity Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
marketable securities, unrealized gain (loss) on securities still held		78		37
Equity Securities [Member] \| FPL [Member]
Schedule of Available-for-sale Securities [Line Items]
marketable securities, unrealized gain (loss) on securities still held		$ 60		$ 37