Income Taxes - Effective Tax Rate Reconciliation (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
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									$ 242,869	$ 225,540	$ 234,695
State income tax net of federal income tax benefit									18,265	18,149	21,387
Credits and favorable adjustments related to prior years resolved in current year									(2,169)	0	(3,356)
Medicare Subsidy Part-D									837	830	823
Allowance for equity funds used during construction (see Note 1)									(9,711)	(8,523)	(6,997)
Palo Verde VIE noncontrolling interest (see Note 18)									(6,626)	(9,135)	(11,862)
Investment tax credit amortization									(5,527)	(4,928)	(3,548)
Other									(218)	(1,228)	(551)
Income tax expense	$ 22,847	$ 139,555	$ 67,371	$ 7,947	$ 5,007	$ 134,753	$ 74,540	$ 6,405	$ 237,720	$ 220,705	$ 230,591
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%	35.00%	35.00%
Income Tax Reconciliation Increases Reductions in Tax Expense [Abstract]
Federal income tax expense at 35% statutory rate									$ 250,267	$ 239,638	$ 246,384
State income tax net of federal income tax benefit									20,433	21,148	23,970
Credits and favorable adjustments related to prior years resolved in current year									(1,892)	0	(3,231)
Medicare Subsidy Part-D									837	830	823
Allowance for equity funds used during construction (see Note 1)									(9,711)	(8,523)	(6,997)
Palo Verde VIE noncontrolling interest (see Note 18)									(6,626)	(9,135)	(11,862)
Investment tax credit amortization									(5,527)	(4,928)	(3,548)
Other									(1,940)	(1,670)	(444)
Income tax expense									$ 245,841	$ 237,360	$ 245,095