Regulatory Matters Regulatory Matters - Deferred Fuel and Purchased Power Regulatory Asset (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Change in regulatory asset
Deferred fuel and purchased power	$ 14,997	$ (26,927)	$ 21,678
Deferred fuel and purchased power amortization	1,617	40,757	31,190
ARIZONA PUBLIC SERVICE COMPANY
Change in regulatory asset
Deferred fuel and purchased power	14,997	(26,927)	21,678
Deferred fuel and purchased power amortization	1,617	40,757	31,190
ACC | ARIZONA PUBLIC SERVICE COMPANY | Power Supply Adjustor (PSA) | Cost Recovery Mechanisms
Change in regulatory asset
Beginning balance	6,926	20,755
Deferred fuel and purchased power	(14,997)	26,927
Deferred fuel and purchased power amortization	(1,617)	(40,756)
Ending balance	$ (9,688)	$ 6,926	$ 20,755