Income Taxes (APSC) (Details 2) (USD $)	1 Months Ended	3 Months Ended					12 Months Ended
	Feb. 28, 2011 Y	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Mar. 31, 2010	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Current:
Federal							$ (310,000)	$ (108,827,000)	$ (38,502,000)
State							15,140,000	25,545,000	(38,080,000)
Total current							14,830,000	(83,282,000)	(76,582,000)
Deferred Income Tax Expense (Benefit), Continuing Operations [Abstract]
Federal							159,566,000	260,236,000	62,874,000
State							16,626,000	10,911,000	42,618,000
Total deferred							176,192,000	260,411,000	105,492,000
Income tax expense - continuing operations		7,375,000	131,416,000	50,818,000	(6,005,000)		183,604,000	160,869,000	138,551,000
Comparison of pretax income from continuing operations at the federal income tax rate to income tax expense - continuing operations
Federal income tax rate (as a percent)							35.00%	35.00%	35.00%
Federal income tax expense at 35% statutory rate							188,733,000	177,002,000	138,110,000
Increases (reductions) in tax expense resulting from:
State income tax net of federal income tax benefit							19,594,000	17,485,000	15,068,000
Credits and favorable adjustments related to prior years resolved in current year								(17,300,000)
Medicare Subsidy Part-D							823,000	1,311,000	(2,095,000)
Allowance for equity funds used during construction							(6,881,000)	(6,563,000)	(4,265,000)
Palo Verde VIE noncontrolling interest							(9,636,000)	(7,057,000)	(6,723,000)
Other							(9,029,000)	(4,009,000)	(1,544,000)
Income tax expense - continuing operations		7,375,000	131,416,000	50,818,000	(6,005,000)		183,604,000	160,869,000	138,551,000
Net deferred income tax liability recognized on the Consolidated Balance Sheets
Current asset		130,571,000					130,571,000	124,897,000
Long-term liability		(1,925,388,000)					(1,925,388,000)	(1,863,861,000)
Deferred income taxes - net		(1,794,817,000)					(1,794,817,000)	(1,738,964,000)
Income Taxes, additional disclosures
Phase-in period of corporate income tax rate reductions beginning in 2014 (in years)	4
Decrease in deferred income tax liabilities					(62,000,000)	42,000,000
Change in regulatory liabilities					62,000,000		37,009,000	56,801,000	82,650,000
ARIZONA PUBLIC SERVICE COMPANY
Current:
Federal							4,633,000	(71,036,000)	(8,667,000)
State							19,104,000	17,406,000	(31,673,000)
Total current							23,737,000	(53,630,000)	(40,340,000)
Deferred Income Tax Expense (Benefit), Continuing Operations [Abstract]
Federal							154,632,000	207,334,000	163,572,000
State							14,173,000	16,761,000	29,342,000
Total deferred							168,805,000	224,095,000	192,914,000
Income tax expense - continuing operations							192,542,000	170,465,000	152,574,000
Comparison of pretax income from continuing operations at the federal income tax rate to income tax expense - continuing operations
Federal income tax rate (as a percent)							35.00%	35.00%	35.00%
Federal income tax expense at 35% statutory rate							194,710,000	184,202,000	148,053,000
Increases (reductions) in tax expense resulting from:
State income tax net of federal income tax benefit							21,139,000	19,186,000	16,691,000
Credits and favorable adjustments related to prior years resolved in current year								(17,300,000)
Medicare Subsidy Part-D							823,000	889,000	(2,025,000)
Allowance for equity funds used during construction							(6,880,000)	(6,563,000)	(4,265,000)
Palo Verde VIE noncontrolling interest							(9,633,000)	(7,057,000)	(6,723,000)
Other							(7,617,000)	(2,892,000)	843,000
Income tax expense - continuing operations							192,542,000	170,465,000	152,574,000
Net deferred income tax liability recognized on the Consolidated Balance Sheets
Current asset		111,503,000					111,503,000	105,042,000
Long-term liability		(1,952,608,000)					(1,952,608,000)	(1,895,654,000)
Deferred income taxes - net		(1,841,105,000)					(1,841,105,000)	(1,790,612,000)
Income Taxes, additional disclosures
Phase-in period of corporate income tax rate reductions beginning in 2014 (in years)	4
Decrease in deferred income tax liabilities					(62,000,000)
Change in regulatory liabilities					$ 62,000,000		$ 37,009,000	$ 56,801,000	$ 82,650,000