Regulatory Matters (Details) (USD $)	12 Months Ended						0 Months Ended	1 Months Ended			1 Months Ended	0 Months Ended	1 Months Ended	3 Months Ended		12 Months Ended					0 Months Ended	12 Months Ended	0 Months Ended	12 Months Ended		1 Months Ended			12 Months Ended		0 Months Ended	1 Months Ended	12 Months Ended		1 Months Ended	0 Months Ended	1 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2013 APS	Dec. 31, 2012 APS	Dec. 31, 2011 APS	Dec. 03, 2013 APS ACC RES implementation plan covering 2014-2018 timeframe	Jan. 31, 2012 Filing with the Arizona Corporation Commission APS ACC Retail rate case filing	Jun. 30, 2011 Filing with the Arizona Corporation Commission APS ACC Retail rate case filing	Jan. 06, 2012 Filing with the Arizona Corporation Commission APS ACC Retail rate case filing	Jan. 31, 2012 Filing with the Arizona Corporation Commission APS ACC Retail rate case filing Maximum	Dec. 30, 2013 Filing with the Arizona Corporation Commission APS ACC Residential customers rate case filing	Dec. 31, 2009 2008 General Retail Rate Case On-Going Impacts APS ACC	Jun. 30, 2010 2008 General Retail Rate Case On-Going Impacts APS ACC 2008 General retail rate case	Dec. 30, 2009 2008 General Retail Rate Case On-Going Impacts APS ACC 2008 General retail rate case item	Dec. 31, 2013 Cost Recovery Mechanisms Power Supply Adjustor (PSA)	Oct. 30, 2013 Cost Recovery Mechanisms APS 2013 DSMAC	Dec. 31, 2012 Cost Recovery Mechanisms APS 2013 DSMAC	Dec. 31, 2013 Cost Recovery Mechanisms APS Power Supply Adjustor (PSA)	Dec. 31, 2013 Cost Recovery Mechanisms APS Power Supply Adjustor (PSA) Maximum	Feb. 12, 2013 Cost Recovery Mechanisms APS Lost Fixed Cost Recovery Mechanism	Dec. 31, 2013 Cost Recovery Mechanisms APS Lost Fixed Cost Recovery Mechanism	Mar. 02, 2014 Cost Recovery Mechanisms APS Lost Fixed Cost Recovery Mechanism Subsequent event	Dec. 31, 2013 Cost Recovery Mechanisms APS ACC RES	Jun. 02, 2012 Cost Recovery Mechanisms APS ACC 2013 DSMAC	Jun. 30, 2012 Cost Recovery Mechanisms APS ACC 2012 DSMAC	Apr. 30, 2012 Cost Recovery Mechanisms APS ACC 2012 DSMAC	Jun. 30, 2011 Cost Recovery Mechanisms APS ACC 2012 DSMAC	Dec. 31, 2009 Cost Recovery Mechanisms APS ACC 2012 DSMAC	Jun. 02, 2011 Cost Recovery Mechanisms APS ACC 2012 DSMAC	Jul. 12, 2013 Cost Recovery Mechanisms APS ACC RES implementation plan covering 2014-2018 timeframe	Feb. 28, 2013 Cost Recovery Mechanisms APS ACC Power Supply Adjustor (PSA)	Dec. 31, 2013 Cost Recovery Mechanisms APS ACC Power Supply Adjustor (PSA)	Dec. 31, 2012 Cost Recovery Mechanisms APS ACC Power Supply Adjustor (PSA)	Feb. 28, 2014 Cost Recovery Mechanisms APS ACC Power Supply Adjustor (PSA) Subsequent event	Jun. 01, 2013 Cost Recovery Mechanisms APS FERC Transmission Rates, Transmission Cost Adjustor and Other Transmission Matters	Jun. 30, 2012 Cost Recovery Mechanisms APS FERC Transmission Rates, Transmission Cost Adjustor and Other Transmission Matters
Regulatory Matters
Net retail rate increase									$ 95,500,000
Approximate percentage of increase in the average retail customer bill									6.60%
Approximate percentage of increase in the average retail customer bill under proposed Four Corners rate filing												2.00%
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)								0.03757
Approved base fuel rate (in dollars per 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%
Annual cost recovery due to modifications to the Environmental Improvement Surcharge											5,000,000
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
2008 General Retail Rate Case on-going impacts
Number of other parties to the settlement agreement															21
Minimum amount of reduction of average annual operational expenses from 2010 through 2014													30,000,000
Authorization and requirements of equity infusions into APS beginning June 1, 2009 through December 31, 2014													700,000,000
Equity infusions into APS														253,000,000
Change in regulatory asset
Plan term																								5 years
Amount of proposed budget																	68,900,000	87,600,000													143,000,000
Percentage of cumulative energy savings for prior year																														3.00%
Percentage of annual energy savings to meet energy efficiency goal for 2011																														2.75%
Period of energy savings goal																												2 years
Demand-side management adjustor charge (DSMAC)																											72,000,000
Period beginning March 1, 2012, over which the costs will be recovered																											12 months
Costs already being recovered in general rates																										10,000,000
Amortization of recovery of demand-side management adjustor charge included in costs already been recovered																													5,000,000
Percentage of cumulative energy savings for current year																									5.00%
Beginning balance																																	73,000,000	28,000,000
Deferred fuel and purchased power costs-current period	(21,678,000)	(71,573,000)	(69,166,000)	(21,678,000)	(71,573,000)	(69,166,000)																											(21,000,000)	(72,000,000)
Amounts (charged) credited to customers	(31,190,000)	116,716,000	155,157,000	(31,190,000)	116,716,000	155,157,000																											(31,000,000)	117,000,000
Ending balance																																	21,000,000	73,000,000
Percentage of sale of distributed energy system's output at a market-based price for installing new rooftop solar system to all new residential customers																															100.00%
Charge on future customers who install rooftop solar panels (in dollars per kWh)							0.70
Estimated monthly collection due to charge on future customers who install rooftop solar panels							4.90
PSA rate (in dollars per kWh)																																			0.001557
PSA rate for prior year (in dollars per kWh)																																0.001329
Increase or decrease in PSA charge (in dollars per kWh)																			0.000228	0.004
Forward component of increase in PSA (in dollars per kWh)																0.001277
Historical component of increase in PSA (in dollars per kWh)																0.000280
Increase in annual wholesale transmission rates																																				26,000,000	16,000,000
Fixed costs recoverable per residential power lost (in dollars per kWh)																						0.031
Fixed costs recoverable per non-residential power lost (in dollars per kWh)																						0.023
Amount of adjustment approved representing prorated sales losses																					$ 5,100,000		$ 25,300,000