Retirement Plans and Other Benefits (Details 4) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Pinnacle West
Employee Savings Plan Benefits
Expenses recorded for the defined contribution savings plan	$ 8,000,000	$ 8,000,000	$ 9,000,000
ARIZONA PUBLIC SERVICE COMPANY
Employee Savings Plan Benefits
APS's employees share of total cost of the plans (as a percent)	99.00%
Pension Benefits
Contributions
Expected contributions in 2013	0
Expected contributions in 2014	89,000,000
Expected contributions in 2015	112,000,000
Actual contribution to benefit plans in the current fiscal year	65,000,000		200,000,000
Estimated Future Benefit Payments
2013	126,091,000
2014	135,602,000
2015	145,438,000
2016	155,774,000
2017	165,535,000
Years 2018-2022	971,362,000
Changes in fair value for assets that are measured at fair value on a recurring basis
Balance at the beginning of the period	1,850,550,000
Balance at the end of the period	2,079,181,000		1,775,596,000
Pension Benefits | Expected contributions
Contributions
Expected contributions in 2013	140,000,000
Expected contributions in 2014	175,000,000
Expected contributions in 2015	175,000,000
Pension Benefits | Pinnacle West
Changes in fair value for assets that are measured at fair value on a recurring basis
Balance at the end of the period	2,079,181,000	1,850,550,000
Pension Benefits | ARIZONA PUBLIC SERVICE COMPANY
Contributions
Actual contribution to benefit plans in the current fiscal year	64,000,000	0	195,000,000
Pension Benefits | Significant Unobservable Inputs (Level 3) | Pinnacle West
Changes in fair value for assets that are measured at fair value on a recurring basis
Balance at the end of the period	2,419,000
Pension Benefits | Real estate | Pinnacle West
Changes in fair value for assets that are measured at fair value on a recurring basis
Balance at the end of the period	117,854,000	106,147,000
Pension Benefits | Short-term investments and other | Pinnacle West
Changes in fair value for assets that are measured at fair value on a recurring basis
Balance at the end of the period	29,278,000	37,191,000
Pension Benefits | Short-term investments and other | Significant Unobservable Inputs (Level 3)
Changes in fair value for assets that are measured at fair value on a recurring basis
Actual return on assets still held	(668,000)
Purchases, sales, and settlements	3,087,000
Balance at the end of the period	2,419,000
Pension Benefits | Short-term investments and other | Significant Unobservable Inputs (Level 3) | Pinnacle West
Changes in fair value for assets that are measured at fair value on a recurring basis
Balance at the end of the period	2,419,000
Other Benefits
Contributions
Expected contributions in 2013	20,000,000
Expected contributions in 2014	20,000,000
Expected contributions in 2015	20,000,000
Actual contribution to benefit plans in the current fiscal year	22,707,000	18,769,000	17,000,000
Estimated Future Benefit Payments
2013	26,934,000
2014	29,870,000
2015	32,929,000
2016	35,893,000
2017	38,765,000
Years 2018-2022	235,170,000
Changes in fair value for assets that are measured at fair value on a recurring basis
Balance at the beginning of the period	608,663,000	567,410,000
Balance at the end of the period	684,221,000	608,663,000	567,410,000
Other Benefits | Pinnacle West
Changes in fair value for assets that are measured at fair value on a recurring basis
Balance at the end of the period	684,221,000	608,663,000
Other Benefits | ARIZONA PUBLIC SERVICE COMPANY
Contributions
Actual contribution to benefit plans in the current fiscal year	22,000,000	19,000,000	16,000,000
Other Benefits | Real estate | Pinnacle West
Changes in fair value for assets that are measured at fair value on a recurring basis
Balance at the end of the period	9,378,000	8,446,000
Other Benefits | Short-term investments and other | Pinnacle West
Changes in fair value for assets that are measured at fair value on a recurring basis
Balance at the end of the period	$ 7,788,000	$ 10,482,000