Other Investments

9 Months Ended

Sep. 30, 2013

Regulated Entity, Other Assets, Noncurrent [Abstract]

Other Investments

Other Investments

Nuclear Decommissioning Trusts

Future decommissioning costs of removal of SCE's nuclear assets are expected to be funded from independent decommissioning trusts, which currently receive contributions of approximately $23 million per year through SCE customer rates.

The following table sets forth amortized cost and fair value of the trust investments:

	Longest Maturity Dates	Amortized Cost						Fair Value
(in millions)		September 30, 2013			December 31, 2012			September 30, 2013			December 31, 2012
Stocks	—	$	635		$	978		$	2,027		$	2,271
Municipal bonds	2051	701			518			796			644
U.S. government and agency securities	2043	861			547			924			603
Corporate bonds	2054	176			324			221			410
Short-term investments, primarily cash equivalents	One-year	351			117			367			121
Total investments		2,724			2,484			4,335			4,049
Net payables		(3		)	(1		)	(3		)	(1		)
Total nuclear decommissioning trusts		$	2,721		$	2,483		$	4,332		$	4,048

Trust fund earnings (based on specific identification) increase the trust fund balance and the ARO regulatory liability. Proceeds from sales of securities (which are reinvested) were $2.6 billion and $428 million for the three months ended September 30, 2013 and 2012, respectively and $4.6 billion and $1.5 billion for the nine months ended September 30, 2013 and 2012, respectively. Unrealized holding gains, net of losses, were $1.6 billion at both September 30, 2013 and December 31, 2012.

The following table sets forth a summary of changes in the fair value of the trust:

	Three months ended September 30,						Nine months ended September 30,
(in millions)	2013			2012			2013			2012
Balance at beginning of period	$	4,182		$	3,810		$	4,048		$	3,592
Gross realized gains	119			13			261			54
Gross realized losses	(17		)	—			(18		)	(5		)
Unrealized gains, net	55			156			46			272
Other-than-temporary impairments	(15		)	(7		)	(44		)	(30		)
Interest, dividends, contributions and other	8			25			39			114
Balance at end of period	$	4,332		$	3,997		$	4,332		$	3,997

Due to regulatory mechanisms, earnings (including other-than-temporary impairments) and realized gains and losses have no impact on operating revenue or earnings.