Lines of Credit and Short-Term Borrowings (Details) (USD $)						12 Months Ended										12 Months Ended			12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2012 Long term debt item	Dec. 31, 2012 Pinnacle West	Nov. 04, 2011 Pinnacle West Revolving credit facility maturing in 2013	Dec. 31, 2012 Pinnacle West Revolving credit facility maturing in 2016	Dec. 31, 2011 Pinnacle West Revolving credit facility maturing in 2016	Nov. 04, 2011 Pinnacle West Revolving credit facility maturing in 2016	Dec. 31, 2012 Pinnacle West Commercial Paper	Dec. 31, 2011 Pinnacle West Commercial Paper	Dec. 31, 2012 ARIZONA PUBLIC SERVICE COMPANY	Dec. 31, 2012 ARIZONA PUBLIC SERVICE COMPANY ACC	Dec. 31, 2012 ARIZONA PUBLIC SERVICE COMPANY Long term debt	Dec. 31, 2011 ARIZONA PUBLIC SERVICE COMPANY Long term debt	Nov. 04, 2011 ARIZONA PUBLIC SERVICE COMPANY Revolving credit facility maturing in 2013	Dec. 31, 2012 ARIZONA PUBLIC SERVICE COMPANY Revolving credit facility maturing in 2016	Dec. 31, 2011 ARIZONA PUBLIC SERVICE COMPANY Revolving credit facility maturing in 2016	Nov. 04, 2011 ARIZONA PUBLIC SERVICE COMPANY Revolving credit facility maturing in 2016	Dec. 31, 2012 ARIZONA PUBLIC SERVICE COMPANY Revolving credit facility maturing in 2015	Dec. 31, 2011 ARIZONA PUBLIC SERVICE COMPANY Revolving credit facility maturing in 2015	Feb. 14, 2011 ARIZONA PUBLIC SERVICE COMPANY Revolving credit facility maturing in 2015	Dec. 31, 2012 ARIZONA PUBLIC SERVICE COMPANY Commercial Paper	Feb. 14, 2011 ARIZONA PUBLIC SERVICE COMPANY Line of Credit Maturing in 2011
Lines of Credit and Short-Term Borrowings
Amount Committed	$ 1,200,000,000	$ 1,200,000,000	$ 908,000,000		$ 200,000,000	$ 200,000,000	$ 200,000,000	$ 200,000,000	$ 200,000,000	$ 200,000,000					$ 500,000,000	$ 500,000,000	$ 500,000,000	$ 500,000,000	$ 500,000,000	$ 500,000,000	$ 500,000,000		$ 489,000,000
Unused Amount	1,108,000,000	1,200,000,000				200,000,000	200,000,000									408,000,000	500,000,000		500,000,000	500,000,000
Commitment Fees (as a percent)						0.225%	0.275%									0.175%	0.225%		0.20%	0.25%
Outstanding amount of debt				3,331,000,000							3,206,000,000											92,000,000
Number of credit facilities			2
Maximum commercial paper support available under credit facility													250,000,000	250,000,000
Maximum borrowing capacity on credit facility upon satisfaction of certain conditions and consent of lenders						300,000,000					700,000,000						700,000,000
Debt Provisions
Percentage of APS's capitalization used in calculation of short-term debt authorization												7.00%
Required amount to be used in purchases of natural gas and power which is used in calculation of short-term debt authorization												500,000,000
Long-term debt authorization before increase												4,200,000,000
Long-term debt authorization												$ 5,100,000,000