SCHEDULE I - CONDENSED FINANCIAL INFORMATION OF REGISTRANT (Details 2) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Current assets
Cash and cash equivalents	$ 26,202	$ 33,583	$ 110,188	$ 145,378
Customer and other receivables	277,225	284,183
Current deferred income taxes	152,191	130,571
Income tax receivable	2,423	6,466
Other current assets	37,102	26,904
Total current assets	1,005,726	956,470
Investments and other assets
Other assets	62,694	64,588
Total investments and other assets	669,210	627,643
TOTAL ASSETS	13,379,615	13,111,018	12,393,000
Current liabilities
Accounts payable	221,312	326,987
Accrued taxes (Note 4)	124,939	120,289
Common dividends payable	59,789
Other current liabilities	171,573	148,616
Total current liabilities	1,083,542	1,342,705
Long-term debt less current maturities	3,199,088	3,019,054
Deferred credits and other
Deferred income taxes	2,151,371	1,925,388
Pension and other postretirement liabilities	1,058,755	1,268,910
Other	283,654	217,934
Total deferred credits and other	4,994,696	4,818,673
Common stock equity
Common stock	2,466,923	2,444,247
Accumulated other comprehensive loss	(114,008)	(152,163)
Retained earnings	1,624,102	1,534,483
Total shareholders' equity	3,972,806	3,821,850
Noncontrolling interests	129,483	108,736
Total equity	4,102,289	3,930,586	3,775,226
TOTAL LIABILITIES AND EQUITY	13,379,615	13,111,018
Pinnacle West
Current assets
Cash and cash equivalents	22,679	12,710	7,725	17,284
Customer and other receivables	92,906	62,418
Current deferred income taxes	77,771	19,068
Income tax receivable	3,350	1,804
Other current assets	25	55
Total current assets	196,731	96,055
Investments and other assets
Investments in subsidiaries	4,223,301	4,026,289
Deferred income taxes		27,220
Other assets	13,833	16,898
Total investments and other assets	4,237,134	4,070,407
TOTAL ASSETS	4,433,865	4,166,462
Current liabilities
Accounts payable	5,735	4,811
Accrued taxes (Note 4)	8,239	9,795
Common dividends payable	59,789
Other current liabilities	41,000	28,295
Total current liabilities	114,763	42,901
Long-term debt less current maturities	125,000	125,000
Deferred credits and other
Deferred income taxes	17,395
Pension and other postretirement liabilities	41,199	32,513
Other	33,218	35,462
Total deferred credits and other	91,812	67,975
Common stock equity
Common stock	2,462,713	2,439,530
Accumulated other comprehensive loss	(114,008)	(152,163)
Retained earnings	1,624,102	1,534,483
Total shareholders' equity	3,972,807	3,821,850
Noncontrolling interests	129,483	108,736
Total equity	4,102,290	3,930,586
TOTAL LIABILITIES AND EQUITY	$ 4,433,865	$ 4,166,462