Regulatory Matters - Additional Information (Details)																										12 Months Ended
	Oct. 01, 2021 $ / kWh	Feb. 22, 2021 USD ($)	Feb. 15, 2021 USD ($)	Feb. 01, 2021 USD ($) $ / kWh	Aug. 20, 2020 USD ($) Customer	Jun. 01, 2020 USD ($)	May 01, 2020 $ / kWh	Feb. 14, 2020 USD ($)	Feb. 01, 2020 $ / kWh	Nov. 14, 2019 USD ($) Customer	Oct. 31, 2019 USD ($)	Oct. 29, 2019 USD ($)	Jun. 01, 2019 USD ($)	May 01, 2019 $ / kWh	Apr. 10, 2019	Feb. 15, 2019 USD ($)	Feb. 01, 2019 $ / kWh	Aug. 13, 2018 USD ($)	Jun. 01, 2018 USD ($)	May 01, 2018 $ / kWh	Feb. 15, 2018 USD ($)	Feb. 01, 2018 $ / kWh	Jan. 08, 2018 USD ($)	Nov. 20, 2017 USD ($)	Dec. 20, 2016 $ / kWh	Dec. 31, 2020 USD ($) program MW	Dec. 31, 2017 $ / kWh	Jul. 01, 2020 USD ($)	May 15, 2020 USD ($)	May 05, 2020 USD ($)	Dec. 31, 2019 USD ($)	Jul. 01, 2019 USD ($)	Mar. 15, 2019 agreement	Dec. 31, 2018 USD ($)	Jun. 29, 2018 USD ($)	Nov. 14, 2017 USD ($)	Sep. 01, 2017 USD ($)
Regulatory Matters [Line Items]
Number of customers | Customer					3,800					13,000
Inconvenience payment					$ 25					$ 25
ARIZONA PUBLIC SERVICE COMPANY
Regulatory Matters [Line Items]
Demand side management funds																														$ 36,000,000
Customer credits																										$ 43,000,000
Customer credits, additional funds																										7,000,000
ARIZONA PUBLIC SERVICE COMPANY | Damage from Fire, Explosion or Other Hazard
Regulatory Matters [Line Items]
Pre-tax income																										$ (23,000,000)
ARIZONA PUBLIC SERVICE COMPANY | 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								$ 26,600,000								$ 36,200,000					$ 60,700,000
Decrease in amount of adjustment representing prorated sales losses								$ 9,600,000								$ 24,500,000
ARIZONA PUBLIC SERVICE COMPANY | ACC
Regulatory Matters [Line Items]
Program term																										18 years
Requested rate decrease for tax act											$ (184,000,000)							$ 86,500,000					$ 119,100,000
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
Number of public utility programs | program																										2
Solar power capacity | MW																										80
ARIZONA PUBLIC SERVICE COMPANY | ACC | Arizona Renewable Energy Standard and Tariff 2018
Regulatory Matters [Line Items]
Amount of proposed budget																												$ 84,700,000				$ 86,300,000			$ 89,900,000
Request to meet revenue requirements																												$ 4,500,000
ARIZONA PUBLIC SERVICE COMPANY | ACC | Demand Side Management Adjustor Charge 2018
Regulatory Matters [Line Items]
Amount of proposed budget																																				$ 52,600,000	$ 52,600,000
ARIZONA PUBLIC SERVICE COMPANY | ACC | Power Supply Adjustor (PSA)
Regulatory Matters [Line Items]
PSA rate (in dollars per kWh) | $ / kWh									(0.000456)								0.001658					0.004555
Forward component of PSA rate (in dollars per kWh) | $ / kWh									(0.002086)								0.000536
Historical component of PSA rate (in dollars per kWh) | $ / kWh									0.001630								0.001122
ARIZONA PUBLIC SERVICE COMPANY | ACC | Net Metering
Regulatory Matters [Line Items]
Cost of service, resource comparison proxy method, maximum annual percentage decrease																									10.00%
Cost of service for interconnected DG system customers, grandfathered period																									20 years
Guaranteed export price period																									10 years
Settlement agreement, energy price for exported energy (in dollars per kWh) | $ / kWh																									0.129
Request second-year energy price for exported energy | $ / kWh							0.094							0.105						0.116
ARIZONA PUBLIC SERVICE COMPANY | ACC | Arizona Renewable Energy Standard and Tariff
Regulatory Matters [Line Items]
Plan term																										5 years
ARIZONA PUBLIC SERVICE COMPANY | ACC | Demand Side Management Adjustor Charge 2019
Regulatory Matters [Line Items]
Amount of proposed budget																																		$ 34,100,000
ARIZONA PUBLIC SERVICE COMPANY | ACC | Demand Side Management Adjustor Charge 2020
Regulatory Matters [Line Items]
Amount of proposed budget																													$ 51,900,000		$ 51,900,000
ARIZONA PUBLIC SERVICE COMPANY | ACC | Demand Side Management Adjustor Charge 2021
Regulatory Matters [Line Items]
Amount of proposed budget																										$ 63,700,000
ARIZONA PUBLIC SERVICE COMPANY | FERC | Transmission rates, transmission cost adjustor and other transmission matters
Regulatory Matters [Line Items]
Rate matters, increase (decrease) in cost recovery						$ (6,100,000)							$ 25,800,000						$ (22,700,000)
Rate matters, increase (decrease) in cost recovery, retail customer rates						$ 10,900,000							$ 4,700,000						$ (26,900,000)
Cost Recovery Mechanisms | ARIZONA PUBLIC SERVICE COMPANY | ACC | Power Supply Adjustor (PSA)
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									(0.002115)								(0.002897)
Number of agreements | agreement																																	2
Solar Communities | ARIZONA PUBLIC SERVICE COMPANY | ACC | Arizona Renewable Energy Standard and Tariff 2018
Regulatory Matters [Line Items]
Program term																								3 years
Minimum | ARIZONA PUBLIC SERVICE COMPANY | ACC
Regulatory Matters [Line Items]
Regulatory impact, operating results											$ 69,000,000
Minimum | Solar Communities | ARIZONA PUBLIC SERVICE COMPANY | ACC | Arizona Renewable Energy Standard and Tariff 2018
Regulatory Matters [Line Items]
Required annual capital investment																								$ 10,000,000
Maximum | Solar Communities | ARIZONA PUBLIC SERVICE COMPANY | ACC | Arizona Renewable Energy Standard and Tariff 2018
Regulatory Matters [Line Items]
Required annual capital investment																								$ 15,000,000
Subsequent Event | ARIZONA PUBLIC SERVICE COMPANY | 2017 Settlement Agreement and its Customer Education and Outreach Plan
Regulatory Matters [Line Items]
Settlement amount		$ 24,750,000
Settlement amount returned to customers		$ 24,000,000
Subsequent Event | ARIZONA PUBLIC SERVICE COMPANY | Lost Fixed Cost Recovery Mechanism
Regulatory Matters [Line Items]
Amount of adjustment approved representing prorated sales losses pending approval			$ 38,500,000
Decrease in amount of adjustment representing prorated sales losses			$ 11,800,000
Subsequent Event | ARIZONA PUBLIC SERVICE COMPANY | FERC | Environmental Improvement Surcharge
Regulatory Matters [Line Items]
Rate matters, increase (decrease) in cost recovery				$ 10,300,000
Rate matters, increase (decrease) in cost recovery, excess of annual amount				$ 1,500,000
Forecast | ARIZONA PUBLIC SERVICE COMPANY | ACC | Power Supply Adjustor (PSA)
Regulatory Matters [Line Items]
PSA rate (in dollars per kWh) | $ / kWh				0.003544
Forward component of PSA rate (in dollars per kWh) | $ / kWh				0.003434
Historical component of PSA rate (in dollars per kWh) | $ / kWh				0.000110
Forecast | ARIZONA PUBLIC SERVICE COMPANY | ACC | Net Metering
Regulatory Matters [Line Items]
Request second-year energy price for exported energy | $ / kWh	0.105
Forecast | Cost Recovery Mechanisms | ARIZONA PUBLIC SERVICE COMPANY | ACC | Power Supply Adjustor (PSA)
Regulatory Matters [Line Items]
PSA rate in prior years (in dollars per kWh) | $ / kWh				0.004