Regulatory Matters (Details 2) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Detail of regulatory assets
Regulatory assets, current	$ 94,000	$ 144,000
Regulatory assets, non-current	1,097,389	1,099,900
ARIZONA PUBLIC SERVICE COMPANY
Detail of regulatory assets
Regulatory assets, current	94,187	143,949
Regulatory assets, non-current	1,097,389	1,099,900
Pension and other postretirement benefits
Detail of regulatory assets
Regulatory assets, non-current	769,000	780,000
Income taxes allowance for funds used during construction (AFUDC) equity
Detail of regulatory assets
Regulatory assets, current	4,000	4,000
Regulatory assets, non-current	93,000	92,000
Deferred fuel and purchased power - mark-to-market
Detail of regulatory assets
Regulatory assets, current		19,000
Regulatory assets, non-current	20,000	21,000
Transmission vegetation management
Detail of regulatory assets
Regulatory assets, current	9,000	9,000
Regulatory assets, non-current	20,000	23,000
Coal reclamation
Detail of regulatory assets
Regulatory assets, current	8,000	8,000
Regulatory assets, non-current	22,000	24,000
Palo Verde VIE
Detail of regulatory assets
Regulatory assets, non-current	39,000	38,000
Deferred compensation
Detail of regulatory assets
Regulatory assets, non-current	35,000	34,000
Deferred fuel and purchased power
Detail of regulatory assets
Regulatory assets, current	41,000	73,000
Tax expense of Medicare subsidy
Detail of regulatory assets
Regulatory assets, current	2,000	2,000
Regulatory assets, non-current	17,000	17,000
Loss on reacquired debt
Detail of regulatory assets
Regulatory assets, current	1,000	2,000
Regulatory assets, non-current	18,000	18,000
Income taxes - investment tax credit basis adjustment
Detail of regulatory assets
Regulatory assets, current	1,000	1,000
Regulatory assets, non-current	31,000	26,000
Pension and other postretirement benefits deferral
Detail of regulatory assets
Regulatory assets, current	8,000	8,000
Regulatory assets, non-current	11,000	13,000
Other
Detail of regulatory assets
Regulatory assets, current	20,000	18,000
Regulatory assets, non-current	$ 22,000	$ 14,000