Investments in Debt and Equity Securities

3 Months Ended

Mar. 31, 2013

Investments in Debt and Equity Securities

Investments in Debt and Equity Securities

(D)

Investments in Debt and Equity Securities. Investment securities we hold are classified as available-for-sale. Available-for-sale securities are carried at market value with unrealized gains and losses, net of any tax effect, added to or deducted from other comprehensive margin, except that, in accordance with our rate-making treatment, unrealized gains and losses from investment securities held in the nuclear decommissioning trust fund are directly added to or deducted from the regulatory asset for asset retirement obligations. Realized gains and losses on the nuclear decommissioning trust fund are also recorded to the regulatory asset. All realized and unrealized gains and losses are determined using the specific identification method. Approximately 94% of these gross unrealized losses were in effect for less than one year.

The following table summarizes the activities for available-for-sale securities as of March 31, 2013 and December 31, 2012.

	Gross Unrealized
		(dollars in thousands)
March 31, 2013		Cost		Gains		Losses			Fair Value
Equity	$	157,649	$	57,796	$	(3,288	)	$	212,157
Debt		166,551		9,691		(4,962	)		171,280
Other		11,028		—		—			11,028
Total	$	335,228	$	67,487	$	(8,250	)	$	394,465

	Gross Unrealized
		(dollars in thousands)
December 31, 2012		Cost		Gains		Losses			Fair Value
Equity	$	153,846	$	45,071	$	(3,675	)	$	195,242
Debt		163,127		10,286		(4,501	)		168,912
Other		13,654		—		—			13,654
Total	$	330,627	$	55,357	$	(8,176	)	$	377,808