v3.7.0.1

Fair Value Measurements (Available for Sale Securities) (Details) - USD ($) $ in Millions | 3 Months Ended | 6 Months Ended | 12 Months Ended
--- | --- | --- | ---
Jun. 30, 2017 | Jun. 30, 2016 | Jun. 30, 2017 | Jun. 30, 2016 | Dec. 31, 2016
Schedule of Available-for-sale Securities [Line Items] |  |  |  |  |
Realized Gains | $ 22 | $ 33 | $ 76 | $ 55 |
Realized Losses | 14 | 20 | 43 | 38 |
Proceeds from Sale and Maturity of Available-for-sale Securities | 627 | 727 | 1,253 | 1,428 |
Unrealized losses on available for sale debt securities |  |  | 16 |  | $ 34
Fair value of available for sale securities in an unrealized loss position | 756 |  | 756 |  | 959
Available For Sale Securities: Special Use Funds - Equity Securities [Member] |  |  |  |  |
Schedule of Available-for-sale Securities [Line Items] |  |  |  |  |
Unrealized gains |  |  | 1,584 |  | 1,396
available for sale securities: Special Use Funds - Debt Securities [Member] |  |  |  |  |
Schedule of Available-for-sale Securities [Line Items] |  |  |  |  |
Unrealized gains |  |  | 36 |  | 22
FPL [Member] |  |  |  |  |
Schedule of Available-for-sale Securities [Line Items] |  |  |  |  |
Realized Gains | 13 | 16 | 26 | 26 |
Realized Losses | 7 | 12 | 26 | 22 |
Proceeds from Sale and Maturity of Available-for-sale Securities | 395 | $ 551 | 836 | $ 1,081 |
Unrealized losses on available for sale debt securities |  |  | 13 |  | 28
Fair value of available for sale securities in an unrealized loss position | $ 575 |  | 575 |  | 722
FPL [Member] | Available For Sale Securities: Special Use Funds - Equity Securities [Member] |  |  |  |  |
Schedule of Available-for-sale Securities [Line Items] |  |  |  |  |
Unrealized gains |  |  | 1,126 |  | 1,007
FPL [Member] | available for sale securities: Special Use Funds - Debt Securities [Member] |  |  |  |  |
Schedule of Available-for-sale Securities [Line Items] |  |  |  |  |
Unrealized gains |  |  | $ 27 |  | $ 17

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- Definition Amount of unrealized loss before deducting unrealized gain on investments in available-for-sale debt 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 + Details
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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 + Details
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