SCHEDULE I CONDENSED FINANCIAL INFORMATION OF REGISTRANT (Details 2) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009	Dec. 31, 2008
Current assets
Cash and cash equivalents	$ 33,583	$ 110,188	$ 145,378	$ 105,245
Customer and other receivables	284,183	324,207
Current deferred income taxes	130,571	124,897
Income tax receivable	6,466	2,483
Other current assets	26,904	28,362
Total current assets	956,470	1,024,511
Investments and other assets
Other assets	64,588	116,216
Total investments and other assets	627,643	625,134
TOTAL ASSETS	13,111,018	12,392,998	12,035,000
Current liabilities
Accounts payable	326,987	236,354
Accrued taxes	120,289	104,711
Short-Term Borrowings		16,600
Current maturities of long-term debt	477,435	631,879
Other current liabilities	148,616	139,063
Total current liabilities	1,342,705	1,449,704
Long-term debt less current maturities	3,019,054	3,045,794
Deferred credits and other
Pension and other postretirement liabilities	1,268,910	813,121
Other	217,934	132,031
Total deferred credits and other	4,818,673	4,122,274
Common stock equity
Common stock	2,444,247	2,421,372
Accumulated other comprehensive loss	(152,163)	(159,767)
Retained earnings	1,534,483	1,423,961
Total shareholders' equity	3,821,850	3,683,327
Noncontrolling interests	108,736	91,899
Total equity	3,930,586	3,775,226	3,428,004
TOTAL LIABILITIES AND EQUITY	13,111,018	12,392,998
Pinnacle West
Current assets
Cash and cash equivalents	12,710	7,725	17,284	6,262
Customer and other receivables	62,418	75,745
Current deferred income taxes	19,068	19,855
Income tax receivable	1,804	3,736
Other current assets	55	61
Total current assets	96,055	107,122
Investments and other assets
Investments in subsidiaries	4,026,289	3,901,935
Deferred income taxes	27,220
Other assets	16,898	58,071
Total investments and other assets	4,070,407	3,960,006
TOTAL ASSETS	4,166,462	4,067,128
Current liabilities
Accounts payable	4,811	4,981
Accrued taxes	9,795	4,216
Short-Term Borrowings		16,600
Current maturities of long-term debt		175,000
Other current liabilities	28,295	28,101
Total current liabilities	42,901	228,898
Long-term debt less current maturities	125,000
Deferred credits and other
Pension and other postretirement liabilities	32,513	28,607
Other	35,462	34,397
Total deferred credits and other	67,975	63,004
Common stock equity
Common stock	2,439,530	2,419,133
Accumulated other comprehensive loss	(152,163)	(159,767)
Retained earnings	1,534,483	1,423,961
Total shareholders' equity	3,821,850	3,683,327
Noncontrolling interests	108,736	91,899
Total equity	3,930,586	3,775,226
TOTAL LIABILITIES AND EQUITY	$ 4,166,462	$ 4,067,128