Long-Term Debt and Liquidity Matters (Details) (USD $)																0 Months Ended	1 Months Ended		1 Months Ended
	Sep. 30, 2012	Dec. 31, 2011	Sep. 30, 2012 Pinnacle West	Dec. 31, 2011 Pinnacle West	Sep. 30, 2012 ARIZONA PUBLIC SERVICE COMPANY	Dec. 31, 2011 ARIZONA PUBLIC SERVICE COMPANY	Sep. 30, 2012 ARIZONA PUBLIC SERVICE COMPANY ACC	Sep. 30, 2012 ARIZONA PUBLIC SERVICE COMPANY ACC Minimum	Sep. 30, 2012 Long term debt ARIZONA PUBLIC SERVICE COMPANY item	Sep. 30, 2012 Revolving credit facility maturing in 2015 ARIZONA PUBLIC SERVICE COMPANY	Sep. 30, 2012 Revolving credit facility maturing in 2016 Pinnacle West	Sep. 30, 2012 Revolving credit facility maturing in 2016 ARIZONA PUBLIC SERVICE COMPANY	Sep. 30, 2012 Pollution Control Revenue Refunding Bonds, 2009 Series B ARIZONA PUBLIC SERVICE COMPANY	May 01, 2012 Pollution Control Revenue Refunding Bonds, 2009 Series B ARIZONA PUBLIC SERVICE COMPANY	Jun. 02, 2012 Pollution Control Revenue Refunding Bonds, 2009 Series A ARIZONA PUBLIC SERVICE COMPANY	Nov. 01, 2012 Pollution Control Revenue Refunding Bonds, 2002 Series A ARIZONA PUBLIC SERVICE COMPANY	Mar. 31, 2012 6.50% senior notes due March 1, 2012 ARIZONA PUBLIC SERVICE COMPANY	Mar. 02, 2012 6.50% senior notes due March 1, 2012 ARIZONA PUBLIC SERVICE COMPANY	Jan. 31, 2012 4.50% unsecured senior notes that mature on April 1, 2042 ARIZONA PUBLIC SERVICE COMPANY	Jan. 13, 2012 4.50% unsecured senior notes that mature on April 1, 2042 ARIZONA PUBLIC SERVICE COMPANY
Long-Term Debt and Liquidity Matters
Number of line of credit facilities									2
Carrying Amount	$ 3,429,000,000	$ 3,496,000,000	$ 125,000,000	$ 125,000,000	$ 3,304,000,000	$ 3,371,000,000
Daily rate (as a percent)													0.20%
Interest rate (as a percent)															1.25%			6.50%		4.50%
Repayment of debt																	375,000,000
Amount of debt redeemed																90,000,000
Current borrowing capacity on credit facility									1,000,000,000	500,000,000	200,000,000	500,000,000
Maximum borrowing capacity on credit facility upon satisfaction of certain conditions and consent of lenders										700,000,000	300,000,000	700,000,000
Notes issued																			325,000,000
Maximum commercial paper support available under credit facility									250,000,000		200,000,000
Aggregate outstanding amount														32,000,000	38,000,000
Estimated fair value of long-term debt, including current maturities
Fair Value	3,942,000,000	3,926,000,000	125,000,000	123,000,000	3,817,000,000	3,803,000,000
Debt Provisions
Total shareholder equity	4,056,242,000	3,821,850,000			4,181,351,000	3,943,007,000	4,200,000,000
Total capitalization							7,400,000,000
Dividend restrictions, shareholder equity required								$ 3,000,000,000
Required common equity ratio ordered by ACC (as a percent)								40.00%