Investments in Debt and Equity Securities

9 Months Ended

Sep. 30, 2017

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 funds are directly added to or deducted from the regulatory asset for asset retirement obligations. Realized gains and losses on the nuclear decommissioning funds are also recorded to the regulatory asset. All realized and unrealized gains and losses are determined using the specific identification method. As of September 30, 2017 approximately 79% of these gross unrealized losses had been unrealized for a duration of less than one year.

The following tables summarize available-for-sale securities as of September 30, 2017 and December 31, 2016.

		Gross Unrealized
		(dollars in thousands)
September 30, 2017		Cost		Gains		Losses			Fair Value
Equity	$	251,021	$	75,181	$	(4,386	)	$	321,816
Debt		224,458		2,194		(1,769	)		224,883
Other		6,604		1		—			6,605
Total	$	482,083	$	77,376	$	(6,155	)	$	553,304

		Gross Unrealized
		(dollars in thousands)
December 31, 2016		Cost		Gains		Losses			Fair Value
Equity	$	237,317	$	51,054	$	(5,041	)	$	283,330
Debt		201,492		1,167		(3,423	)		199,236
Other		3,339		—		(2	)		3,337
Total	$	442,148	$	52,221	$	(8,466	)	$	485,903