XML 128 R19.htm IDEA: XBRL DOCUMENT
v3.19.3.a.u2

Investments | 12 Months Ended
--- | ---
Dec. 31, 2019
Regulated Entity, Other Assets, Noncurrent [Abstract] |
Investments | Investments Nuclear Decommissioning Trusts Future decommissioning costs related to SCE's nuclear assets are expected to be funded from independent decommissioning trusts. The following table sets forth amortized cost and fair value of the trust investments (see Note 4 for a discussion of fair value of the trust investments):
| Longest Maturity Date |  | Amortized Cost |  | Fair Value
|  | December 31,
(in millions) |  | 2019 |  | 2018 |  | 2019 |  | 2018
Stocks | — |  | N/A |  |  | N/A |  |  | $ | 1,765 |  |  | $ | 1,381 |
Municipal bonds | 2057 |  | 822 |  |  | 665 |  |  | 970 |  |  | 767 |
U.S. government and agency securities | 2067 |  | 996 |  |  | 1,193 |  |  | 1,115 |  |  | 1,288 |
Corporate bonds | 2068 |  | 597 |  |  | 573 |  |  | 679 |  |  | 611 |
Short-term investments and receivables/payables 1 | One-year |  | 32 |  |  | 70 |  |  | 33 |  |  | 73 |
Total |  |  | $ | 2,447 |  |  | $ | 2,501 |  |  | $ | 4,562 |  |  | $ | 4,120 |
1 | Short-term investments include $41 million and $71 million of repurchase agreements payable by financial institutions which earn interest, are fully secured by U.S. Treasury securities and mature by January 2, 2020 and January 2, 2019 as of December 31, 2019 and 2018, respectively.
Trust fund earnings (based on specific identification) increase the trust fund balance and the ARO regulatory liability. Unrealized holding gains, net of losses, were $1.8 billion and $1.4 billion at December 31, 2019 and 2018, respectively, and other-than-temporary impairments were $160 million and $170 million at the respective periods. Trust assets are used to pay income taxes. Deferred tax liabilities related to net unrealized gains at December 31, 2019 were $449 million. Accordingly, the fair value of trust assets available to pay future decommissioning costs, net of deferred income taxes, totaled $4.1 billion at December 31, 2019. The following table summarizes the gains and losses for the trust investments:
| December 31,
(in millions) | 2019 | 2018 | 2017
Gross realized gains | $ | 87 |  | $ | 134 |  | $ | 244 |
Gross realized losses | (2 | ) | (27 | ) | (23 | )
Net unrealized gains (losses) for equity securities | 343 |  | (233 | ) | 142 |
Due to regulatory mechanisms, changes in assets of the trusts from income or loss items have no impact on operating revenue or earnings.

X
- Definition The entire disclosure for investments in certain debt and equity securities. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 320 -URI http://asc.fasb.org/subtopic&trid=2209399 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 946 -SubTopic 320 -URI http://asc.fasb.org/subtopic&trid=2324412 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -URI http://asc.fasb.org/topic&trid=2196928 Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 940 -SubTopic 320 -URI http://asc.fasb.org/subtopic&trid=2176304 + Details
Name: | us-gaap_InvestmentsInDebtAndMarketableEquitySecuritiesAndCertainTradingAssetsDisclosureTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- References No definition available. + Details
Name: | us-gaap_RegulatedEntityOtherAssetsNoncurrentAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration