Investments

12 Months Ended

Dec. 31, 2020

Regulated Entity, Other Assets, Noncurrent [Abstract]

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)		2020		2019		2020		2019
Stocks	—	N/A		N/A		$	1,908	$	1,765
Municipal bonds	2057	1,013		822		1,218		970
U.S. government and agency securities	2067	740		996		864		1,115
Corporate bonds	2070	460		597		550		679
Short-term investments and receivables/payables1	One-year	281		32		293		33
Total		$	2,494	$	2,447	$	4,833	$	4,562

1 Short-term investments include $138 million and $41 million of repurchase agreements payable by financial institutions which earn interest, are fully secured by U.S. Treasury securities and mature by January 4, 2021 and January 2, 2020 as of December 31, 2020 and 2019, 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 $2.1 billion and $1.8 billion at December 31, 2020 and 2019, respectively.

Trust assets are used to pay income taxes. Deferred tax liabilities related to net unrealized gains were $515 million and $449 million at December 31, 2020 and December 31, 2019, respectively. Accordingly, the fair value of trust assets available to pay future decommissioning costs, net of deferred income taxes, totaled $4.3 billion and $4.1 billion at December 31, 2020 and December 31, 2019, respectively.

The following table summarizes the gains and losses for the trust investments:


	December 31,
(in millions)	2020		2019		2018
Gross realized gains	$	255	$	87	$	134
Gross realized losses	(6)		(2)		(27)
Net unrealized gains (losses) for equity securities	176		343		(233)

Due to regulatory mechanisms, changes in assets of the trusts from income or loss items have no impact on operating revenue or earnings.