Regulatory Matters (Details)												2 Months Ended	3 Months Ended	6 Months Ended		12 Months Ended
	Jun. 01, 2016 USD ($)	Feb. 01, 2016 $ / kWh	Jan. 15, 2016 USD ($)	Jan. 01, 2016 USD ($)	Jun. 01, 2015 USD ($)	Mar. 02, 2015 USD ($)	Nov. 04, 2014	Apr. 15, 2014 Customer MW	Mar. 01, 2014 USD ($)	Jan. 01, 2014 USD ($) $ / kWh	Jan. 06, 2012 USD ($) $ / kWh	Apr. 30, 2014 workshop	Jan. 31, 2016 $ / kWh	Jun. 30, 2016 USD ($) $ / kWh	Jun. 30, 2015 USD ($)	Dec. 31, 2015 USD ($) $ / kWh	Jul. 12, 2016 USD ($)	Jul. 01, 2016 USD ($)	Apr. 01, 2016 USD ($)	Jan. 12, 2016 USD ($)	Nov. 25, 2015 USD ($)	Mar. 20, 2015 project	Dec. 19, 2014 MW
Change in regulatory asset
Deferred fuel and purchased power costs — current period														$ 21,026,000	$ (11,711,000)
Amounts charged to customers														(13,778,000)	(11,424,000)
APS
Change in regulatory asset
Deferred fuel and purchased power costs — current period														21,026,000	(11,711,000)
Amounts charged to customers														$ (13,778,000)	(11,424,000)
RES 2014 | APS | AZ Sun Program
Settlement Agreement
Request to build additional utility scale solar, capacity | MW								20
RES 2014 | APS | Alternative to AZ Sun Program
Settlement Agreement
Request to build additional utility scale solar, capacity | MW								10
Additional capacity from APS-owned non AZ Sun projects, impacted customers | Customer								1,500
RES 2014 | APS | Alternative to AZ Sun Program, Phase 1
Settlement Agreement
Request to build additional utility scale solar, capacity | MW																							8
RES 2014 | APS | Alternative to AZ Sun Program Phase 2
Settlement Agreement
Request to build additional utility scale solar, capacity | MW																							2
Lost Fixed Cost Recovery Mechanisms | APS
Change in regulatory asset
Fixed costs recoverable per residential power lost (in dollars per kWh) | $ / kWh														0.031
Fixed costs recoverable per non-residential power lost (in dollars per kWh) | $ / kWh														0.023
Percentage of retail revenues														1.00%
Amount of adjustment representing prorated sales losses approval			$ 46,400,000			$ 38,500,000			$ 25,300,000
Increase in amount of adjustment representing prorated sales losses			$ 7,900,000
ACC | Retail Rate Case Filing with Arizona Corporation Commission | APS
Settlement Agreement
Net change in base rates											$ 0
Non-fuel base rate increase											116,300,000
Fuel-related base rate decrease											$ 153,100,000
Current base fuel rate (in dollars per kWh) | $ / kWh											0.03757
Approved base fuel rate (in dollars per kWh) | $ / kWh											0.03207
Estimated amount of transfer of cost recovery for certain renewable energy projects from the RES surcharge to base rates											$ 36,800,000
Authorized return on common equity (as a percent)											10.00%
Percentage of debt in capital structure											46.10%
Percentage of common equity in capital structure											53.90%
Deferral of property taxes in 2012, if Arizona property tax rates increase (as a percent)											25.00%
Deferral of property taxes in 2013, if Arizona property tax rates increase (as a percent)											50.00%
Deferral of property taxes for 2014 and subsequent years, if Arizona property tax rates increase (as a percent)											75.00%
Deferral of property taxes in all years, if Arizona property tax rates decrease (as a percent)											100.00%
Elimination of the sharing provision of fuel and purchased power costs											9
Period to process the subsequent rate cases											12 months
ACC staff sufficiency findings, general period of time											30 days
Change in regulatory asset
Reduced system benefits charge, amount				$ 14,600,000
ACC | Retail Rate Case Filing with Arizona Corporation Commission | APS | Maximum
Settlement Agreement
Annual cost recovery due to modifications to the Environmental Improvement Surcharge											$ 5,000,000
ACC | RES | APS
Settlement Agreement
Plan term														5 years
ACC | RES 2016 | APS
Settlement Agreement
Amount of approved budget																				$ 148,000,000
ACC | RES 2017 | APS
Settlement Agreement
Amount of proposed budget																		$ 150,000,000
ACC | DSMAC 2015 | APS
Settlement Agreement
Amount of approved budget																			$ 68,900,000		$ 68,900,000
Number of resource savings projects | project																						3
ACC | DSMAC 2015 | Subsequent Event | APS
Settlement Agreement
Additional budget approved																	$ 4,000,000
ACC | DSMC 2016 | APS
Settlement Agreement
Amount of approved budget					$ 68,900,000
ACC | Electric energy efficiency standard | APS
Settlement Agreement
Number of workshops | workshop												3
Number of days to convene a workshop							120 days
ACC | Power Supply Adjustor (PSA) | APS
Change in regulatory asset
Beginning balance				$ (9,688,000)										$ (9,688,000)	6,925,000	$ 6,925,000
Deferred fuel and purchased power costs — current period														21,027,000	(11,710,000)
Amounts charged to customers														(13,778,000)	(11,424,000)
Ending balance														$ (2,439,000)	$ (16,209,000)	$ (9,688,000)
PSA rate (in dollars per kWh) | $ / kWh		0.001678
PSA rate for prior year (in dollars per kWh) | $ / kWh																0.000887
Forward component of increase in PSA (in dollars per kWh) | $ / kWh		0.001975
Historical component of increase in PSA (in dollars per kWh) | $ / kWh		(0.000297)
Transition component increase in PSA (in dollars per kWh) | $ / kWh													(0.004936)
ACC | Net Metering | APS
Change in regulatory asset
Charge on future customers who install rooftop solar panels (in dollars per kWh) | $ / kWh										0.70				0.70
Estimated monthly collection due to charge on future customers who install rooftop solar panels										$ 4.90
United States Federal Energy Regulatory Commission | Open Access Transmission Tariff [Member] | APS
Change in regulatory asset
Decrease in annual wholesale transmission rates					$ 17,600,000
Increase in annual wholesale transmission rates	$ 24,900,000