Nuclear Decommissioning Trusts (Details) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012	Dec. 31, 2012
Nuclear decommissioning trust fund assets
Fair Value	$ 595,231,000		$ 595,231,000		$ 570,625,000
Realized gains and losses and proceeds from the sale of securities by the nuclear decommissioning trust funds
Proceeds from the sale of securities			253,996,000	211,138,000
Fair value of fixed income securities, summarized by contractual maturities
Total	595,231,000		595,231,000		570,625,000
ARIZONA PUBLIC SERVICE COMPANY
Nuclear decommissioning trust fund assets
Fair Value	595,231,000		595,231,000		570,625,000
Unrealized Gains	107,000,000		107,000,000		91,000,000
Unrealized Losses	(6,000,000)		(6,000,000)
Net payables for securities purchases	(6,000,000)		(6,000,000)		(4,000,000)
Realized gains and losses and proceeds from the sale of securities by the nuclear decommissioning trust funds
Realized gains	1,000,000	2,000,000	3,000,000	4,000,000
Realized losses	(1,000,000)	(1,000,000)	(2,000,000)	(2,000,000)
Proceeds from the sale of securities	119,000,000	119,000,000	253,996,000	211,138,000
Fair value of fixed income securities, summarized by contractual maturities
Total	595,231,000		595,231,000		570,625,000
ARIZONA PUBLIC SERVICE COMPANY | Equity Securities
Nuclear decommissioning trust fund assets
Fair Value	233,000,000		233,000,000		204,000,000
Unrealized Gains	93,000,000		93,000,000		67,000,000
Fair value of fixed income securities, summarized by contractual maturities
Total	233,000,000		233,000,000		204,000,000
ARIZONA PUBLIC SERVICE COMPANY | Fixed income securities.
Nuclear decommissioning trust fund assets
Fair Value	368,000,000		368,000,000		371,000,000
Unrealized Gains	14,000,000		14,000,000		24,000,000
Unrealized Losses	(6,000,000)		(6,000,000)
Fair value of fixed income securities, summarized by contractual maturities
Less than one year	11,000,000		11,000,000
1 year - 5 years	106,000,000		106,000,000
5 years - 10 years	100,000,000		100,000,000
Greater than 10 years	151,000,000		151,000,000
Total	$ 368,000,000		$ 368,000,000		$ 371,000,000