Long-Term Debt and Liquidity Matters (Details) (USD $)						1 Months Ended										1 Months Ended		1 Months Ended
	Sep. 30, 2011	Dec. 31, 2010	Sep. 30, 2011 Pinnacle West	Feb. 23, 2011 Pinnacle West	Dec. 31, 2010 Pinnacle West	Sep. 30, 2011 Pinnacle West Term loan facility	Feb. 28, 2011 Pinnacle West 5.91% Senior Notes	Feb. 23, 2011 Pinnacle West 5.91% Senior Notes	Sep. 30, 2011 Pinnacle West Credit facility maturing in 2013	Sep. 30, 2011 ARIZONA PUBLIC SERVICE COMPANY	Dec. 31, 2010 ARIZONA PUBLIC SERVICE COMPANY	Sep. 30, 2011 ARIZONA PUBLIC SERVICE COMPANY Line of credit facilities	Sep. 30, 2011 ARIZONA PUBLIC SERVICE COMPANY Credit facility maturing in 2013	Sep. 30, 2011 ARIZONA PUBLIC SERVICE COMPANY New Revolving credit facility maturing in 2015	Feb. 14, 2011 ARIZONA PUBLIC SERVICE COMPANY New Revolving credit facility maturing in 2015	Feb. 28, 2011 ARIZONA PUBLIC SERVICE COMPANY Revolving credit facility maturing in 2011	Sep. 30, 2011 ARIZONA PUBLIC SERVICE COMPANY ACC	Aug. 31, 2011 5.05% unsecured senior notes due 2041	Aug. 25, 2011 5.05% unsecured senior notes due 2041	Aug. 25, 2011 6.375% senior notes due 2011	Sep. 30, 2011 Line of credit facilities loc	Sep. 07, 2011 Pollution Control Revenue Refunding Bonds
Long-Term Debt and Liquidity Matters
Aggregate principal amount				$ 175,000,000																$ 400,000,000		$ 27,000,000
Interest rate (as a percent)								5.91%											5.05%	6.375%
Repayment of debt						40,000,000	175,000,000
Current borrowing capacity on credit facility									200,000,000			1,000,000,000	500,000,000	500,000,000
Refinanced credit facility																489,000,000
Maximum commercial paper support available under credit facility									200,000,000			250,000,000
Maximum borrowing capacity on credit facility upon satisfaction of certain conditions and consent of lenders									300,000,000					700,000,000
Notes issued																		300,000,000
Number of line of credit facilities																					2
Estimated fair value of long-term debt, including current maturities
Carrying Amount	3,923,000,000	3,678,000,000	135,000,000		175,000,000					3,788,000,000	3,503,000,000
Fair Value	4,354,000,000	3,913,000,000	135,000,000		176,000,000					4,219,000,000	3,737,000,000
Letter of credit															20,000,000
Debt Provisions
Required minimum common equity ratio ordered by ACC (as a percent)																	40.00%
Total shareholder equity	3,894,085,000	3,683,327,000								4,013,441,000	3,824,953,000						4,000,000,000
Total capitalization																	7,700,000,000
Dividend restrictions, minimum total shareholder equity required																	$ 3,100,000,000