Nuclear Decommissioning Trusts (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Nuclear decommissioning trust fund assets
Fair Value	$ 779,586	$ 735,196
Realized gains and losses and proceeds from the sale of securities by the nuclear decommissioning trust funds
Proceeds from the sale of securities	633,410	478,813	$ 356,195
Fair value of fixed income securities, summarized by contractual maturities
Total	779,586	735,196
ARIZONA PUBLIC SERVICE COMPANY
Nuclear decommissioning trust fund assets
Fair Value	779,586	735,196
Unrealized Gains	197,911	169,053
Unrealized Losses	(4,962)	(2,760)
Net receivables for securities purchases	795
Net payables for securities purchases		(335)
Realized gains and losses and proceeds from the sale of securities by the nuclear decommissioning trust funds
Realized gains	11,213	5,189	4,725
Realized losses	(10,106)	(6,225)	(4,525)
Proceeds from the sale of securities	633,410	478,813	$ 356,195
Fair value of fixed income securities, summarized by contractual maturities
Total	779,586	735,196
ARIZONA PUBLIC SERVICE COMPANY | Equity Securities
Nuclear decommissioning trust fund assets
Fair Value	353,261	314,957
Unrealized Gains	188,091	157,098
Unrealized Losses	0	(115)
Fair value of fixed income securities, summarized by contractual maturities
Total	353,261	314,957
ARIZONA PUBLIC SERVICE COMPANY | Fixed income securities
Nuclear decommissioning trust fund assets
Fair Value	425,530	420,574
Unrealized Gains	9,820	11,955
Unrealized Losses	(4,962)	(2,645)
Fair value of fixed income securities, summarized by contractual maturities
Less than one year	13,063
1 year - 5 years	119,292
5 years - 10 years	105,612
Greater than 10 years	187,563
Total	$ 425,530	$ 420,574