Income Taxes - Effective Tax Rate Reconciliation (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
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									$ 244,278	$ 242,869	$ 225,540
State income tax net of federal income tax benefit									16,311	18,265	18,149
Credits and favorable adjustments related to prior years resolved in current year									0	(2,169)	0
Medicare Subsidy Part-D									844	837	830
Allowance for equity funds used during construction (see Note 1)									(11,724)	(9,711)	(8,523)
Palo Verde VIE noncontrolling interest (see Note 18)									(6,823)	(6,626)	(9,135)
Investment tax credit amortization									(5,887)	(5,527)	(4,928)
Other									(588)	(218)	(1,228)
Income tax expense	$ 27,309	$ 141,446	$ 65,742	$ 1,914	$ 22,847	$ 139,555	$ 67,371	$ 7,947	$ 236,411	$ 237,720	$ 220,705
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									$ 254,617	$ 250,267	$ 239,638
State income tax net of federal income tax benefit									18,750	20,433	21,148
Credits and favorable adjustments related to prior years resolved in current year									0	(1,892)	0
Medicare Subsidy Part-D									844	837	830
Allowance for equity funds used during construction (see Note 1)									(11,724)	(9,711)	(8,523)
Palo Verde VIE noncontrolling interest (see Note 18)									(6,823)	(6,626)	(9,135)
Investment tax credit amortization									(5,887)	(5,527)	(4,928)
Other									(3,935)	(1,940)	(1,670)
Income tax expense									$ 245,842	$ 245,841	$ 237,360