Document and Entity Information - shares	6 Months Ended
	Jun. 30, 2020	Jul. 30, 2020
Entity Information [Line Items]
Entity Shell Company	false
Entity Interactive Data Current	Yes
Security Exchange Name	NYSE
Trading Symbol	PNW
Title of 12(b) Security	Common Stock
Entity Tax Identification Number	86-0512431
Entity Address, Address Line One	400 North Fifth Street, P.O. Box 53999
Entity Address, City or Town	Phoenix
Entity Address, State or Province	AZ
Entity Address, Postal Zip Code	85072-3999
City Area Code	(602)
Local Phone Number	250-1000
Entity File Number	1-8962
Document Transition Report	false
Document Quarterly Report	true
Entity Registrant Name	PINNACLE WEST CAPITAL CORPORATION
Entity Central Index Key	0000764622
Document Type	10-Q
Document Period End Date	Jun. 30, 2020
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Entity Current Reporting Status	Yes
Entity Filer Category	Large Accelerated Filer
Entity Emerging Growth Company	false
Entity Small Business	false
Entity Common Stock, Shares Outstanding (in shares)		112,556,967
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	Q2
Entity Incorporation, State or Country Code	AZ
APS
Entity Information [Line Items]
Entity Shell Company	false
Entity Interactive Data Current	Yes
Entity Tax Identification Number	86-0011170
Entity Address, Address Line One	400 North Fifth Street, P.O. Box 53999
Entity Address, City or Town	Phoenix
Entity Address, State or Province	AZ
Entity Address, Postal Zip Code	85072-3999
City Area Code	(602)
Local Phone Number	250-1000
Entity File Number	1-4473
Entity Registrant Name	ARIZONA PUBLIC SERVICE COMPANY
Entity Central Index Key	0000007286
Document Type	10-Q
Document Period End Date	Jun. 30, 2020
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Entity Current Reporting Status	Yes
Entity Filer Category	Non-accelerated Filer
Entity Emerging Growth Company	false
Entity Small Business	false
Entity Common Stock, Shares Outstanding (in shares)		71,264,947
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	Q2
Entity Incorporation, State or Country Code	AZ