Regulatory Matters - Cost Recovery Mechanisms (Details) - Arizona Public Service Company																						12 Months Ended
	Feb. 15, 2022 USD ($)	Feb. 01, 2022 USD ($) $ / kWh	Nov. 01, 2021 $ / kWh	Jul. 01, 2021 USD ($)	Jun. 07, 2021 USD ($)	Jun. 01, 2021 USD ($)	Apr. 01, 2021 $ / kWh	Feb. 15, 2021 USD ($)	Feb. 01, 2021 USD ($) $ / kWh	Jun. 01, 2020 USD ($)	Feb. 14, 2020 USD ($)	Feb. 01, 2020 $ / kWh	Oct. 31, 2019 USD ($) $ / kWh	Oct. 29, 2019 USD ($)	Jun. 01, 2019 USD ($)	Apr. 10, 2019	Feb. 15, 2019 USD ($)	Feb. 01, 2019 $ / kWh	Aug. 13, 2018 USD ($)	Feb. 01, 2018 $ / kWh	Nov. 20, 2017 USD ($)	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)	Dec. 31, 2017 $ / kWh	Dec. 17, 2021 USD ($)	Dec. 09, 2021 USD ($)	Oct. 28, 2021 agreement	Jul. 01, 2020 USD ($)	Jun. 30, 2020 USD ($)	May 15, 2020 USD ($)	May 05, 2020 USD ($)	Dec. 31, 2019 USD ($)	Jul. 01, 2019 USD ($)	Mar. 15, 2019 agreement	Nov. 14, 2017 USD ($)	Sep. 01, 2017 USD ($)
Regulatory Matters [Line Items]
Demand side management funds																															$ 36,000,000
Customer credits																						$ 43,000,000							$ 43,000,000
Customer credits, additional funds																						$ 7,000,000							$ 7,000,000
ACC
Regulatory Matters [Line Items]
Program term																							18 years
Requested rate decrease for tax act													$ (184,000,000)						$ 86,500,000
Requested rate increase (decrease), deferred taxes amortization, period																28 years 6 months
Requested rate increase (decrease), amount, one-time bill credit														$ 64,000,000
Requested rate increase (decrease), amount, one-time bill credit, additional benefit														$ 39,500,000
Arizona Renewable Energy Standard and Tariff | ACC
Regulatory Matters [Line Items]
Plan term																						5 years
Arizona Renewable Energy Standard and Tariff 2018 | ACC
Regulatory Matters [Line Items]
Amount of proposed budget				$ 93,100,000																						$ 100,500,000		$ 84,700,000					$ 86,300,000
Request to meet revenue requirements																												$ 4,500,000
Authorized amount to be collected					$ 68,300,000
Arizona Renewable Energy Standard and Tariff 2018 | ACC | Minimum
Regulatory Matters [Line Items]
Authorized spending in capital costs				20,000,000
Arizona Renewable Energy Standard and Tariff 2018 | ACC | Maximum
Regulatory Matters [Line Items]
Authorized spending in capital costs				$ 30,000,000
Arizona Renewable Energy Standard and Tariff 2018 | ACC | Solar Communities
Regulatory Matters [Line Items]
Program term																					3 years
Arizona Renewable Energy Standard and Tariff 2018 | ACC | Solar Communities | Minimum
Regulatory Matters [Line Items]
Required annual capital investment																					$ 10,000,000
Arizona Renewable Energy Standard and Tariff 2018 | ACC | Solar Communities | Maximum
Regulatory Matters [Line Items]
Required annual capital investment																					$ 15,000,000
Demand Side Management Adjustor Charge 2018 | ACC
Regulatory Matters [Line Items]
Amount of proposed budget																																			$ 52,600,000	$ 52,600,000
Demand Side Management Adjustor Charge 2019 | ACC
Regulatory Matters [Line Items]
Amount of proposed budget																																$ 34,100,000
Demand Side Management Adjustor Charge 2020 | ACC
Regulatory Matters [Line Items]
Amount of proposed budget																							$ 51,900,000							$ 51,900,000
Demand Side Management Adjustor Charge 2021 | ACC
Regulatory Matters [Line Items]
Amount of proposed budget																							$ 63,700,000
Demand Side Management Adjustor Charge 2022 | ACC
Regulatory Matters [Line Items]
Amount of proposed budget																									$ 78,400,000
Rate Matter, Increase (Decrease) in Proposed Budget																									$ 14,000,000
Power Supply Adjustor (PSA) | ACC
Regulatory Matters [Line Items]
PSA rate (in dollars per kWh) | $ / kWh			0.003544				0.001544		0.003544			(0.000456)						0.001658		0.004555
Forward component of PSA rate (in dollars per kWh) | $ / kWh			(0.004444)				(0.004444)		0.003434			(0.002086)						0.000536
Historical component of PSA rate (in dollars per kWh) | $ / kWh			0.007988				0.005988		0.000110			0.001630						0.001122
Fuel and purchased power costs above annual cap									$ 215,900,000
Power Supply Adjustor (PSA) | ACC | Subsequent Event
Regulatory Matters [Line Items]
PSA rate (in dollars per kWh) | $ / kWh		0.007544
Forward component of PSA rate (in dollars per kWh) | $ / kWh		(0.004842)
Historical component of PSA rate (in dollars per kWh) | $ / kWh		0.012386
Fuel and purchased power costs above annual cap		$ 365,000,000
Power Supply Adjustor (PSA) | ACC | Cost Recovery Mechanisms
Regulatory Matters [Line Items]
Maximum increase decrease in PSA rate (in dollars per kWh) | $ / kWh												0.004
PSA rate in prior years (in dollars per kWh) | $ / kWh									0.004			(0.002115)						(0.002897)
Number of agreements | agreement																											3							2
Power Supply Adjustor (PSA) | ACC | Cost Recovery Mechanisms | Subsequent Event
Regulatory Matters [Line Items]
PSA rate in prior years (in dollars per kWh) | $ / kWh		0.004
Environmental Improvement Surcharge | FERC
Regulatory Matters [Line Items]
Rate matters, increase (decrease) in cost recovery									$ 11,400,000
Rate matters, increase (decrease) in cost recovery, excess of annual amount									$ 1,100,000
Transmission rates, transmission cost adjustor and other transmission matters | FERC
Regulatory Matters [Line Items]
Rate matters, increase (decrease) in cost recovery						$ 4,000,000				$ (6,100,000)					$ 25,800,000
Rate matters, increase (decrease) in cost recovery, wholesale customer rates						(3,200,000)				4,800,000					21,100,000
Rate matters, increase (decrease) in cost recovery, retail customer rates						7,200,000				(10,900,000)					4,700,000
Increase (decrease) in retail revenue requirement						$ (28,400,000)				$ (7,400,000)					$ 4,900,000
Lost Fixed Cost Recovery Mechanism
Regulatory Matters [Line Items]
Fixed costs recoverable per power lost (in dollars per kWh) | $ / kWh																								0.025
Rate matter cap percentage of retail revenue																						1.00%
Amount of adjustment approved representing prorated sales losses pending approval								$ 38,500,000			$ 26,600,000						$ 36,200,000
Increase (decrease) in amount of adjustment representing prorated sales losses								$ 11,800,000			$ (9,600,000)						$ (24,500,000)
Lost Fixed Cost Recovery Mechanism | Subsequent Event
Regulatory Matters [Line Items]
Amount of adjustment approved representing prorated sales losses pending approval	$ 59,100,000
Increase (decrease) in amount of adjustment representing prorated sales losses	$ 32,500,000
Retail Rate Case Filing with Arizona Corporation Commission | Minimum
Regulatory Matters [Line Items]
Fixed costs recoverable per power lost (in dollars per kWh) | $ / kWh													0.0256
Retail Rate Case Filing with Arizona Corporation Commission | Maximum
Regulatory Matters [Line Items]
Fixed costs recoverable per power lost (in dollars per kWh) | $ / kWh													0.0268