Nuclear Decommissioning Trusts (Tables)

12 Months Ended

Dec. 31, 2013

Nuclear Decommissioning Trusts

Fair value of APS's nuclear decommissioning trust fund assets

The following table includes the unrealized gains and losses based on the original cost of the investment and summarizes the fair value of APS’s nuclear decommissioning trust fund assets at December 31, 2013 and December 31, 2012 (dollars in millions):

	Fair Value			Total  Unrealized  Gains		Total  Unrealized  Losses
December 31, 2013
Equity securities	$	272		$	129	$	—
Fixed income securities	373			11		(6		)
Net payables (a)	(3		)	—		—
Total	$	642		$	140	$	(6	)

	Fair Value			Total  Unrealized  Gains		Total  Unrealized  Losses
December 31, 2012
Equity securities	$	204		$	67	$	—
Fixed income securities	371			24		—
Net payables (a)	(4		)	—		—
Total	$	571		$	91	$	—

(a) Net payables relate to pending purchases and sales of securities.

Realized gains and losses and proceeds from the sale of securities by the nuclear decommissioning trust funds

The following table sets forth approximate gains and losses and proceeds from the sale of securities by the nuclear decommissioning trust funds (dollars in millions):

	Year Ended December 31,
	2013			2012			2011
Realized gains	$	6		$	7		$	8
Realized losses	(7		)	(4		)	(5		)
Proceeds from the sale of securities (a)	446			418			498

(a) Proceeds are reinvested in the trust.

Fair value of fixed income securities, summarized by contractual maturities

The fair value of fixed income securities, summarized by contractual maturities, at December 31, 2013 is as follows (dollars in millions):

	Fair Value
Less than one year	$	9
1 year – 5 years	109
5 years – 10 years	108
Greater than 10 years	147
Total	$	373