Income Taxes - Effective Tax Rate Reconciliation (Details) (USD $)	3 Months Ended								12 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
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%
Income Tax Reconciliation Increases Reductions in Tax Expense [Abstract]
Federal income tax expense at 35% statutory rate									$ 225,540,000	$ 234,695,000	$ 229,709,000
State income tax net of federal income tax benefit									18,149,000	21,387,000	23,819,000
Credits and favorable adjustments related to prior years resolved in current year									0	(3,356,000)	0
Medicare Subsidy Part-D									830,000	823,000	483,000
Allowance for equity funds used during construction									(8,523,000)	(6,997,000)	(6,158,000)
Palo Verde VIE noncontrolling interest									(9,135,000)	(11,862,000)	(11,065,000)
Effective Income Tax Rate Reconciliation, Tax Credit, Investment, Amount									(4,928,000)	(3,548,000)	(2,030,000)
Other									(1,228,000)	(551,000)	2,559,000
INCOME TAXES (Note 4)	5,007,000	134,753,000	74,540,000	6,405,000	9,167,000	131,912,000	77,043,000	12,469,000	220,705,000	230,591,000	237,317,000
ARIZONA PUBLIC SERVICE COMPANY
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%
Income Tax Reconciliation Increases Reductions in Tax Expense [Abstract]
Federal income tax expense at 35% statutory rate									239,638,000	246,384,000	235,027,000
State income tax net of federal income tax benefit									21,148,000	23,970,000	25,379,000
Credits and favorable adjustments related to prior years resolved in current year									0	(3,231,000)	0
Medicare Subsidy Part-D									830,000	823,000	483,000
Allowance for equity funds used during construction									(8,523,000)	(6,997,000)	(6,158,000)
Palo Verde VIE noncontrolling interest									(9,135,000)	(11,862,000)	(11,065,000)
Effective Income Tax Rate Reconciliation, Tax Credit, Investment, Amount									(4,928,000)	(3,548,000)	(2,030,000)
Other									(1,670,000)	(444,000)	2,760,000
INCOME TAXES (Note 4)									$ 237,360,000	$ 245,095,000	$ 244,396,000