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v3.20.2

Non-Derivative Fair Value Measurements (Details) - USD ($) $ in Millions | 9 Months Ended | 12 Months Ended
--- | --- | ---
Sep. 30, 2020 | Dec. 31, 2019
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |
Unrealized Gain on Securities | $ 770 |  | $ 706 |
Unrealized Loss on Securities | 13 |  | 6 |
Nuclear decommissinoning fund [Abstract] |  |  |  |
Equity investments in unconsolidated subsidiaries | 160 |  | 155 |
Miscellaneous investments | 132 |  | 136 |
Debt Securities, Available-for-sale, Fair Value, Fiscal Year Maturity [Abstract] |  |  |  |
Due in one year or less | 1 |  |  |
Due in 1 to 5 years | 109 |  |  |
Due in 5 to 10 years | 208 |  |  |
Due after 10 years | 241 |  |  |
Total | 559 |  |  |
Nuclear Decommissioning Fund | Fair Value Measured on a Recurring Basis | Cost |  |  |  |
Nuclear decommissinoning fund [Abstract] |  |  |  |
Decommissioning Fund Investments | 1,764 | [1] | 1,740 | [2]
Nuclear Decommissioning Fund | Fair Value Measured on a Recurring Basis | Cost | Cash equivalents |  |  |  |
Nuclear decommissinoning fund [Abstract] |  |  |  |
Cash equivalents | 22 | [1] | 33 | [2]
Nuclear Decommissioning Fund | Fair Value Measured on a Recurring Basis | Cost | Commingled funds |  |  |  |
Nuclear decommissinoning fund [Abstract] |  |  |  |
Commingled funds | 773 | [1] | 733 | [2]
Nuclear Decommissioning Fund | Fair Value Measured on a Recurring Basis | Cost | Debt securities |  |  |  |
Nuclear decommissinoning fund [Abstract] |  |  |  |
Debt securities | 519 | [1] | 489 | [2]
Nuclear Decommissioning Fund | Fair Value Measured on a Recurring Basis | Cost | Equity securities |  |  |  |
Nuclear decommissinoning fund [Abstract] |  |  |  |
Equity securities | 450 | [1] | 485 | [2]
Nuclear Decommissioning Fund | Fair Value Measured on a Recurring Basis | Fair Value |  |  |  |
Nuclear decommissinoning fund [Abstract] |  |  |  |
Alternative investment | 956 | [1] | 935 | [2]
Nuclear Decommissioning Fund | Fair Value Measured on a Recurring Basis | Fair Value | Cash equivalents |  |  |  |
Nuclear decommissinoning fund [Abstract] |  |  |  |
Cash equivalents | 22 | [1] | 33 | [2]
Alternative investment | 0 | [1] | 0 | [2]
Nuclear Decommissioning Fund | Fair Value Measured on a Recurring Basis | Fair Value | Commingled funds |  |  |  |
Nuclear decommissinoning fund [Abstract] |  |  |  |
Commingled funds | 956 | [1] | 935 | [2]
Alternative investment | 956 | [1] | 935 | [2]
Nuclear Decommissioning Fund | Fair Value Measured on a Recurring Basis | Fair Value | Debt securities |  |  |  |
Nuclear decommissinoning fund [Abstract] |  |  |  |
Debt securities | 559 | [1] | 508 | [2]
Alternative investment | 0 | [1] | 0 | [2]
Nuclear Decommissioning Fund | Fair Value Measured on a Recurring Basis | Fair Value | Equity securities |  |  |  |
Nuclear decommissinoning fund [Abstract] |  |  |  |
Equity securities | 984 | [1] | 964 | [2]
Alternative investment | 0 | [1] | 0 | [2]
Decommissioning Fund Investments | 2,521 | [1] | 2,440 | [2]
Nuclear Decommissioning Fund | Fair Value Measured on a Recurring Basis | Fair Value | Level 1 |  |  |  |
Nuclear decommissinoning fund [Abstract] |  |  |  |
Decommissioning Fund Investments | 1,005 | [1] | 995 | [2]
Nuclear Decommissioning Fund | Fair Value Measured on a Recurring Basis | Fair Value | Level 1 | Cash equivalents |  |  |  |
Nuclear decommissinoning fund [Abstract] |  |  |  |
Cash equivalents | 22 | [1] | 33 | [2]
Nuclear Decommissioning Fund | Fair Value Measured on a Recurring Basis | Fair Value | Level 1 | Commingled funds |  |  |  |
Nuclear decommissinoning fund [Abstract] |  |  |  |
Commingled funds | 0 | [1] | 0 | [2]
Nuclear Decommissioning Fund | Fair Value Measured on a Recurring Basis | Fair Value | Level 1 | Debt securities |  |  |  |
Nuclear decommissinoning fund [Abstract] |  |  |  |
Debt securities | 0 | [1] | 0 | [2]
Nuclear Decommissioning Fund | Fair Value Measured on a Recurring Basis | Fair Value | Level 1 | Equity securities |  |  |  |
Nuclear decommissinoning fund [Abstract] |  |  |  |
Equity securities | 983 | [1] | 962 | [2]
Nuclear Decommissioning Fund | Fair Value Measured on a Recurring Basis | Fair Value | Level 2 |  |  |  |
Nuclear decommissinoning fund [Abstract] |  |  |  |
Decommissioning Fund Investments | 547 | [1] | 497 | [2]
Nuclear Decommissioning Fund | Fair Value Measured on a Recurring Basis | Fair Value | Level 2 | Cash equivalents |  |  |  |
Nuclear decommissinoning fund [Abstract] |  |  |  |
Cash equivalents | 0 | [1] | 0 | [2]
Nuclear Decommissioning Fund | Fair Value Measured on a Recurring Basis | Fair Value | Level 2 | Commingled funds |  |  |  |
Nuclear decommissinoning fund [Abstract] |  |  |  |
Commingled funds | 0 | [1] | 0 | [2]
Nuclear Decommissioning Fund | Fair Value Measured on a Recurring Basis | Fair Value | Level 2 | Debt securities |  |  |  |
Nuclear decommissinoning fund [Abstract] |  |  |  |
Debt securities | 546 | [1] | 495 | [2]
Nuclear Decommissioning Fund | Fair Value Measured on a Recurring Basis | Fair Value | Level 2 | Equity securities |  |  |  |
Nuclear decommissinoning fund [Abstract] |  |  |  |
Equity securities | 1 | [1] | 2 | [2]
Nuclear Decommissioning Fund | Fair Value Measured on a Recurring Basis | Fair Value | Level 3 |  |  |  |
Nuclear decommissinoning fund [Abstract] |  |  |  |
Decommissioning Fund Investments | 13 | [1] | 13 | [2]
Nuclear Decommissioning Fund | Fair Value Measured on a Recurring Basis | Fair Value | Level 3 | Cash equivalents |  |  |  |
Nuclear decommissinoning fund [Abstract] |  |  |  |
Cash equivalents | 0 | [1] | 0 | [2]
Nuclear Decommissioning Fund | Fair Value Measured on a Recurring Basis | Fair Value | Level 3 | Commingled funds |  |  |  |
Nuclear decommissinoning fund [Abstract] |  |  |  |
Commingled funds | 0 | [1] | 0 | [2]
Nuclear Decommissioning Fund | Fair Value Measured on a Recurring Basis | Fair Value | Level 3 | Debt securities |  |  |  |
Nuclear decommissinoning fund [Abstract] |  |  |  |
Debt securities | 13 | [1] | 13 | [2]
Nuclear Decommissioning Fund | Fair Value Measured on a Recurring Basis | Fair Value | Level 3 | Equity securities |  |  |  |
Nuclear decommissinoning fund [Abstract] |  |  |  |
Equity securities |  | [1] | $ 0 | [2]
[1] | Reported in nuclear decommissioning fund and other investments on the consolidated balance sheets, which also includes $160 million of equity investments in unconsolidated subsidiaries and $132 million of rabbi trust assets and miscellaneous investments.
[2] | Reported in nuclear decommissioning fund and other investments on the consolidated balance sheets, which also includes $155 million of equity investments in unconsolidated subsidiaries and $136 million of rabbi trust assets and miscellaneous investments.

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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 + Details
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