Changes in Accumulated Other Comprehensive Loss (APSC) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Changes in accumulated other comprehensive income (loss) by component
Beginning balance	$ (114,008)
Other comprehensive income before reclassifications, net of tax expense	58
Tax (provision) benefit	38
Amounts reclassified from accumulated other comprehensive loss
Net realized loss, net of tax benefit	5,053
Tax benefit	3,300
Amortization of actuarial loss, net of tax benefit	890
Tax benefit	582
Amortization of prior service cost, net of tax benefit	76
Tax benefit	49
Total reclassifications for the period, net of tax benefit	6,019
Tax benefit	3,931
Net current period other comprehensive income, net of tax expense	6,077	(15,614)
Tax benefit	3,969
Ending balance	(107,931)
Derivative Instruments
Changes in accumulated other comprehensive income (loss) by component
Beginning balance	(49,592)
Other comprehensive income before reclassifications, net of tax expense	58
Tax (provision) benefit	38
Amounts reclassified from accumulated other comprehensive loss
Net realized loss, net of tax benefit	5,053
Tax benefit	3,300
Total reclassifications for the period, net of tax benefit	5,053
Tax benefit	3,300
Net current period other comprehensive income, net of tax expense	5,111
Tax benefit	3,338
Ending balance	(44,481)
Pension and other postretirement benefits
Changes in accumulated other comprehensive income (loss) by component
Beginning balance	(64,416)
Amounts reclassified from accumulated other comprehensive loss
Amortization of actuarial loss, net of tax benefit	890
Tax benefit	582
Amortization of prior service cost, net of tax benefit	76
Tax benefit	49
Total reclassifications for the period, net of tax benefit	966
Tax benefit	631
Net current period other comprehensive income, net of tax expense	966
Tax benefit	631
Ending balance	(63,450)
ARIZONA PUBLIC SERVICE COMPANY
Changes in accumulated other comprehensive income (loss) by component
Beginning balance	(89,095)
Other comprehensive income before reclassifications, net of tax expense	58
Tax (provision) benefit	38
Amounts reclassified from accumulated other comprehensive loss
Net realized loss, net of tax benefit	5,052
Tax benefit	3,300
Amortization of actuarial loss, net of tax benefit	808
Tax benefit	527
Amortization of prior service cost, net of tax benefit	74
Tax benefit	49
Total reclassifications for the period, net of tax benefit	5,934
Tax benefit	3,876
Net current period other comprehensive income, net of tax expense	5,992	(15,755)
Tax benefit	3,914
Ending balance	(83,103)
ARIZONA PUBLIC SERVICE COMPANY | Derivative Instruments
Changes in accumulated other comprehensive income (loss) by component
Beginning balance	(49,592)
Other comprehensive income before reclassifications, net of tax expense	58
Tax (provision) benefit	38
Amounts reclassified from accumulated other comprehensive loss
Net realized loss, net of tax benefit	5,052
Tax benefit	3,300
Total reclassifications for the period, net of tax benefit	5,052
Tax benefit	3,300
Net current period other comprehensive income, net of tax expense	5,110
Tax benefit	3,338
Ending balance	(44,482)
ARIZONA PUBLIC SERVICE COMPANY | Pension and other postretirement benefits
Changes in accumulated other comprehensive income (loss) by component
Beginning balance	(39,503)
Amounts reclassified from accumulated other comprehensive loss
Amortization of actuarial loss, net of tax benefit	808
Tax benefit	527
Amortization of prior service cost, net of tax benefit	74
Tax benefit	49
Total reclassifications for the period, net of tax benefit	882
Tax benefit	576
Net current period other comprehensive income, net of tax expense	882
Tax benefit	576
Ending balance	$ (38,621)