Summary of Significant Accounting Policies (Details) (USD $)	12 Months Ended			0 Months Ended	12 Months Ended				36 Months Ended	12 Months Ended	36 Months Ended	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Apr. 21, 2011 ARIZONA PUBLIC SERVICE COMPANY	Dec. 31, 2012 ARIZONA PUBLIC SERVICE COMPANY item	Dec. 31, 2011 ARIZONA PUBLIC SERVICE COMPANY	Dec. 31, 2010 ARIZONA PUBLIC SERVICE COMPANY	Dec. 31, 2008 ARIZONA PUBLIC SERVICE COMPANY item	Dec. 31, 2012 Minimum	Dec. 31, 2012 Maximum	Dec. 31, 2012 Maximum	Dec. 31, 2012 Fossil plant	Dec. 31, 2012 Nuclear plant	Dec. 31, 2012 Other generation	Dec. 31, 2012 Transmission	Dec. 31, 2012 Distribution	Dec. 31, 2012 Other:
Approximate remaining average useful lives of utility property
Average useful life												16 years	27 years	26 years	39 years	35 years	7 years
Extension period of operating licenses for each of the three Palo Verde units				20 years				20 years
Number of VIE lessor trusts					3			3
Depreciation rates (as a percent)	2.71%	2.98%	2.98%						0.45%		12.08%
Allowance for Funds Used During Construction
Composite rate used to calculate AFUDC (as a percent)	8.60%	10.25%	9.20%
Nuclear Fuel
Charges for the permanent disposal of spent nuclear fuel (in dollars per kWh)					0.001
Cash paid during the year for:
Income taxes, net of (refunds)	$ 2,543,000	$ 10,324,000	$ (23,447,000)		$ 1,196,000	$ 25,975,000	$ 81,339,000
Interest, net of amounts capitalized	200,923,000	217,789,000	221,728,000		196,038,000	210,995,000	208,251,000
Significant non-cash investing and financing activities:
Accrued capital expenditures	26,208,000	27,245,000	19,226,000		26,208,000	27,245,000	19,226,000
Dividends declared but not paid	59,789,000				59,800,000
Intangible Assets
Amortization expense	50,000,000	47,000,000	45,000,000
Estimated amortization expense on existing intangible assets over the next five years
2013	45,000,000
2014	37,000,000
2015	28,000,000
2016	20,000,000
2017	$ 12,000,000
Weighted average remaining amortization period for intangible assets	6 years				29 years
Investments
Ownership percentage for classification as cost method investments by El Dorado										20.00%