Stock-Based Compensation (Details 2) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Additional disclosures
Total unrecognized compensation cost related to nonvested share-based compensation arrangements granted	$ 17,000,000
Expected weighted-average period of recognition of unrecognized compensation cost	2 years
Total fair value of shares vested	19,000,000	14,000,000	11,000,000
Compensation cost that has been charged against income	32,000,000	23,000,000	15,000,000
Total income tax benefit recognized	13,000,000	9,000,000	6,000,000
ARIZONA PUBLIC SERVICE COMPANY
Additional disclosures
Compensation cost that has been charged against income	32,000,000	22,000,000	15,000,000
Stock Options
Stock option activity under prior equity incentive plans
Outstanding at the beginning of the period (in shares)	22,958
Exercised (in shares)	15,033
Outstanding at the end of the period (in shares)	7,925	22,958
Exercisable at the end of the period (in shares)	7,925
Weighted-Average Exercise Price
Outstanding at the beginning of the period (in dollars per share)	$ 34.75
Exercised (in dollars per share)	$ 36.05
Outstanding at the end of the period (in dollars per share)	$ 32.29	$ 34.75
Exercisable at the end of the period (in dollars per share)	$ 32.29
Weighted-Average Remaining Contractual Term
Outstanding at the end of the period	2 months 16 days
Exercisable at the end of the period	2 months 16 days
Aggregate Intrinsic Value
Outstanding at the end of the period	148,000
Exercisable at the end of the period	148,000
Additional disclosures
Cash received from options exercised	$ 500,000	$ 1,800,000	$ 4,600,000
Stock Options | Maximum
Stock-Based Compensation
Share Based Compensation Arrangements By Share Based Payment Award Options Expiration Term	10 years