Regulatory Matters - Cost Recovery Mechanisms (Details)																												1 Months Ended	3 Months Ended		12 Months Ended
	Mar. 10, 2023 USD ($)	Feb. 23, 2023 USD ($) $ / kWh	Feb. 01, 2023 USD ($) $ / kWh	Sep. 23, 2022 MW	Jul. 12, 2022 USD ($) $ / kWh	Jun. 01, 2022 USD ($)	Mar. 31, 2022 USD ($) MW	Feb. 15, 2022 USD ($)	Feb. 01, 2022 USD ($) $ / kWh $ / KWH_Kilowatt_hour	Nov. 01, 2021 $ / kWh	Oct. 01, 2021 $ / kWh	Jun. 07, 2021 USD ($)	Jun. 01, 2021 USD ($)	Apr. 01, 2021 $ / kWh	Feb. 15, 2021 USD ($)	Feb. 01, 2021 USD ($) $ / kWh	Aug. 20, 2020 USD ($) customer	Jul. 01, 2020 USD ($)	May 01, 2020 $ / kWh	Feb. 01, 2020 $ / kWh	Nov. 14, 2019 USD ($) customer	Oct. 31, 2019 $ / KWH_Kilowatt_hour	Oct. 29, 2019 USD ($)	May 01, 2019 $ / kWh	Apr. 10, 2019	Aug. 13, 2018 USD ($)	Sep. 01, 2017	Mar. 31, 2021	Mar. 31, 2023 USD ($)	Mar. 31, 2022 USD ($)	Dec. 31, 2020 USD ($) program MW	Dec. 31, 2017 $ / kWh	Dec. 31, 2017 $ / KWH_Kilowatt_hour	Nov. 30, 2022 USD ($)	Jul. 01, 2022 USD ($)	Apr. 18, 2022 USD ($)	Dec. 31, 2021 USD ($)	Dec. 17, 2021 USD ($)	Dec. 09, 2021 USD ($)	Oct. 28, 2021 agreement	Jul. 01, 2021 USD ($)	May 15, 2020 USD ($)	May 05, 2020 USD ($)	Dec. 31, 2019 USD ($)	Mar. 15, 2019 agreement
Change in regulatory asset
Deferred fuel and purchased power costs — current period																													$ 90,305,000	$ 6,110,000
Amounts charged to customers																													(80,904,000)	(39,442,000)
Rate plan comparison tool, number of customers | customer																	3,800				13,000
Rate plan comparison tool, inconvenience payment																	$ 25				$ 25
APS
Settlement Agreement
Demand side management funds																																											$ 36,000,000
Customer credits																																					$ 43,000,000
Customer credits, additional funds																																					$ 7,000,000
Change in regulatory asset
Deferred fuel and purchased power costs — current period																													90,305,000	6,110,000
Amounts charged to customers																													$ (80,904,000)	(39,442,000)
Percentage increase under PSA effective for first billing cycle beginning April 2021																												50.00%
Remaining percentage increase under PSA effective for first billing cycle beginning November 2021																												50.00%
Lost Fixed Cost Recovery Mechanisms | APS
Change in regulatory asset
Fixed cost recoverable per power lost (in dollars per kWh)																																0.025	2.56
Percentage of retail revenues																													1.00%
Amount of adjustment representing prorated sales losses pending approval								$ 59,100,000							$ 38,500,000
Increase (decrease) in amount of adjustment representing prorated sales losses								$ 32,500,000							$ 11,800,000
ACC | APS
Settlement Agreement
Program term																															18 years
Change in regulatory asset
Amount requested to be returned in form of tax savings to customers																										$ 86,500,000
Deferred taxes amortization, period																									28 years 6 months
Public Utilities, one-time bill credit																							$ 64,000,000
Public Utilities, one-time bill credit, additional benefit																							$ 39,500,000
Number of programs | program																															2
Solar capacity (in MW) | MW																															80
ACC | RES | APS
Settlement Agreement
Plan term																													5 years
ACC | RES 2018 | APS
Settlement Agreement
Amount of proposed budget																		$ 84,700,000																	$ 86,200,000				$ 100,500,000		$ 93,100,000
Revenue requirements																		$ 4,500,000
Authorized amount to be collected												$ 68,300,000
ACC | RES 2018 | APS | Solar Communities
Settlement Agreement
Program term					3 years													3 years
ACC | Retail Rate Case Filing with Arizona Corporation Commission | APS
Settlement Agreement
Commercial customers, market pricing, threshold | MW				140			280
ACC | Demand Side Management Adjustor Charge 2020 | APS
Settlement Agreement
Amount of proposed budget																																										$ 51,900,000		$ 51,900,000
ACC | Net Metering | APS
Change in regulatory asset
Cost of service, resource comparison proxy method, maximum annual percentage decrease					10.00%																						10.00%
Cost of service for interconnected DG system customers, grandfathered period																											20 years
Cost of service for new customers, guaranteed export price period																											10 years
Second-year export energy price (in dollars per kWh) | $ / kWh					0.0846						0.094								0.094					0.105
ACC | Demand Side Management Adjustor Charge 2021 | APS
Settlement Agreement
Amount of proposed budget																															$ 63,700,000
ACC | Demand Side Management Adjustor Charge 2022 | APS
Settlement Agreement
Amount of proposed budget																																						$ 78,400,000
Increase in proposed budget																																						$ 14,000,000
ACC | Power Supply Adjustor (PSA) | APS
Change in regulatory asset
Beginning balance																													$ 460,561,000	388,148,000
Deferred fuel and purchased power costs — current period																													90,305,000	6,110,000
Amounts charged to customers																													(80,904,000)	(39,442,000)
Ending balance							$ 354,816,000																						$ 469,962,000	$ 354,816,000
PSA rate (in dollars per kWh) | $ / kWh		0.019074	0.006						0.007544	0.003544				0.001544		0.003544
PSA rate for prior year (in dollars per kWh) | $ / kWh		(0.005527)							0.004842	(0.004444)				(0.004444)		0.003434
Forward component of increase in PSA (in dollars per kWh) | $ / kWh		0.013071							0.012386	0.007988				0.005988		0.000110
Fuel and purchased power costs above annual cap																$ 215,900,000
Transition Component Of PSA Rate1 | $ / kWh		0.011530
Regulatory Clause, Deferred Fuel And Purchased Power Costs, Balancing Account, Depletion Period		24 months
Regulatory Clause, Deferred Fuel And Purchased Power Costs, Balancing Account, Reporting Threshold Amount		$ 500,000
ACC | Demand Side Management Adjustor Charge 2023 | APS
Settlement Agreement
Amount of proposed budget																																		$ 88,000,000
FERC | Environmental Improvement Surcharge | APS
Change in regulatory asset
Rate matter, environmental surcharge cap rate (in dollars per kWh) | $ / KWH_Kilowatt_hour									0.0005
Rate matter, environmental surcharge cap rate amount	$ 4,000,000
Increase (decrease) in annual wholesale transmission rates	(10,700,000)		$ 14,700,000
Rate matters, increase (decrease) in cost recovery, excess of annual amount	$ (7,500,000)		$ 3,300,000
FERC | Open Access Transmission Tariff | APS
Change in regulatory asset
Increase (decrease) in annual wholesale transmission rates						$ 33,000,000							$ 4,000,000
Decrease in wholesale customer rates						6,400,000							3,200,000
Increase (decrease) in retail customer rates						(26,600,000)							7,200,000
Increase (decrease) in retail revenue requirements						$ (2,400,000)							$ (28,400,000)
Cost Recovery Mechanisms | ACC | Power Supply Adjustor (PSA) | APS
Settlement Agreement
Maximum increase decrease in PSA rate | $ / kWh																				0.004
Change in regulatory asset
Historical component of increase in PSA (in dollars per kWh) | $ / kWh									0.004							0.004
Cost recovery, number of agreements | agreement																																								3					2
Minimum | ACC | RES 2018 | APS
Settlement Agreement
Authorized spending					$ 20,000,000
Minimum | ACC | RES 2018 | APS | Solar Communities
Settlement Agreement
Required annual capital investment																		$ 10,000,000
Minimum | FERC | Environmental Improvement Surcharge | APS
Change in regulatory asset
Rate matter, environmental surcharge cap rate amount									$ 13,000,000
Maximum | Retail Rate Case Filing with Arizona Corporation Commission | APS
Change in regulatory asset
Fixed cost recoverable per power lost (in dollars per kWh) | $ / KWH_Kilowatt_hour																						2.68
Maximum | ACC | RES 2018 | APS
Settlement Agreement
Authorized spending					$ 30,000,000
Maximum | ACC | RES 2018 | APS | Solar Communities
Settlement Agreement
Required annual capital investment																		$ 15,000,000
Maximum | FERC | Environmental Improvement Surcharge | APS
Change in regulatory asset
Rate matter, environmental surcharge cap rate amount									$ 15,000,000
Damage from Fire, Explosion or Other Hazard | APS
Change in regulatory asset
Past due balance threshold qualifying for payment extension																																				$ 75