Lines of Credit and Short-Term Borrowings - Schedule of Credit Facilities (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Lines of Credit and Short-Term Borrowings
Commercial paper	$ 0	$ (147,400)
Pinnacle West
Lines of Credit and Short-Term Borrowings
Commercial paper	$ 0	$ 0
Commitment fees (as a percent)	0.125%	0.175%
ARIZONA PUBLIC SERVICE COMPANY
Lines of Credit and Short-Term Borrowings
Commercial paper	$ 0	$ (147,400)
Commitment fees (as a percent)	0.10%	0.125%
Revolving credit facility
Lines of Credit and Short-Term Borrowings
Amount committed	$ 1,200,000	$ 1,200,000
Unused amount	1,200,000	1,052,600
Revolving credit facility | Pinnacle West
Lines of Credit and Short-Term Borrowings
Amount committed	200,000	200,000
Unused amount	200,000	200,000
Revolving credit facility | ARIZONA PUBLIC SERVICE COMPANY
Lines of Credit and Short-Term Borrowings
Amount committed	1,000,000	1,000,000
Unused amount	$ 1,000,000	$ 852,600