Retirement Plans and Other Benefits Retirement Plans and Other Benefits (Details)	1 Months Ended	12 Months Ended
	Jul. 31, 2012	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)	Dec. 31, 2012 USD ($)	Dec. 31, 2011 USD ($)	Jan. 01, 2015 Age
Plan Design Changes [Abstract]
Noncurrent asset		$ 166,206,000	$ 185,997,000
Amount of other postretirement benefit trust assets for union employee medical costs		140,000,000
Amount of pension and other postretirement benefit costs deferred						$ 14,000,000	$ 11,000,000
Regulatory asset amortization period	3 years
Amortization of regulatory assets			5,000,000	$ 8,000,000	$ 8,000,000	$ 4,000,000
Change in mortality assumptions impact on pension and other postretirement obligations			67,000,000
Partnership funding commitments, contribution amount (up to)		75,000,000
Partnership funding commitments, funded amount		54,000,000
Pension Benefits
Plan Design Changes [Abstract]
Noncurrent asset		$ 0	0
Expected long-term return on plan assets for next fiscal year (as a percent)		6.55%
Contributions
Employer's contributions under the plan		$ 100,000,000	100,000,000	175,000,000
Minimum contributions under MAP-21
Minimum contributions under MAP-21		0
Voluntary employer contributions over next three years (up to)		$ 300,000,000
Pension Benefits | Fixed income securities
Target asset allocation
Target allocation (as a percent)		58.00%
Target allocation, minimum (as a percent)		55.00%
Target allocation, maximum (as a percent)		61.00%
Actual asset allocation (as a percent)		57.00%
Pension Benefits | Return-generating assets
Target asset allocation
Target allocation (as a percent)		42.00%
Target allocation, minimum (as a percent)		39.00%
Target allocation, maximum (as a percent)		45.00%
Actual asset allocation (as a percent)		43.00%
Pension Benefits | Developed equities
Target asset allocation
Target allocation (as a percent)		22.00%
Pension Benefits | Emerging equities
Target asset allocation
Target allocation (as a percent)		6.00%
Pension Benefits | Alternative investments
Target asset allocation
Target allocation (as a percent)		14.00%
Other postretirement benefits
Plan Design Changes [Abstract]
Age eligible for benefit | Age								65
Effect of plan amendment on net periodic benefit cost				10,000,000
Effect of plan amendment on expense				5,000,000
Effect of plan amendment on accumulated benefit obligation				316,000,000
Noncurrent asset		$ 166,206,000	185,997,000
Expected long-term return on plan assets for next fiscal year (as a percent)		6.37%
Contributions
Employer's contributions under the plan		$ 819,000	791,000	1,000,000
Expected employer contributions
2017 (less than)		1,000,000
2018 (less than)		1,000,000
2019 (less than)		$ 1,000,000
Other postretirement benefits | Fixed income
Target asset allocation
Actual asset allocation (as a percent)		51.00%
Other postretirement benefits | Non-fixed income
Target asset allocation
Actual asset allocation (as a percent)		49.00%
Pinnacle West
Employee savings plan benefits
Expenses recorded for the defined contribution savings plan		$ 10,000,000	9,000,000	9,000,000
ARIZONA PUBLIC SERVICE COMPANY
Plan Design Changes [Abstract]
Noncurrent asset		$ 162,911,000	182,625,000
Employee savings plan benefits
APS's employees share of total cost of the plans (as a percent)		99.00%
ARIZONA PUBLIC SERVICE COMPANY | Pension Benefits
Contributions
Employer's contributions under the plan		$ 100,000,000	100,000,000	175,000,000
ARIZONA PUBLIC SERVICE COMPANY | Other postretirement benefits
Contributions
Employer's contributions under the plan		$ 1,000,000	$ 1,000,000	$ 1,000,000