Changes in Accumulated Other Comprehensive Loss (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Changes in accumulated other comprehensive income (loss) by component
Beginning balance	$ (78,053)	$ (114,008)
OCI (loss) before reclassifications	(6,229)	5,381
Amounts reclassified from accumulated other comprehensive loss	16,141	30,574
Total other comprehensive income	9,912	35,955	38,155
Ending balance	(68,141)	(78,053)	(114,008)
Derivative Instruments
Changes in accumulated other comprehensive income (loss) by component
Beginning balance	(23,058)	(49,592)
OCI (loss) before reclassifications	(810)	(213)
Amounts reclassified from accumulated other comprehensive loss	13,483	26,747
Total other comprehensive income	12,673	26,534
Ending balance	(10,385)	(23,058)
Pension and other postretirement benefits
Changes in accumulated other comprehensive income (loss) by component
Beginning balance	(54,995)	(64,416)
OCI (loss) before reclassifications	(5,419)	5,594
Amounts reclassified from accumulated other comprehensive loss	2,658	3,827
Total other comprehensive income	(2,761)	9,421
Ending balance	(57,756)	(54,995)
ARIZONA PUBLIC SERVICE COMPANY
Changes in accumulated other comprehensive income (loss) by component
Beginning balance	(53,372)	(89,095)
OCI (loss) before reclassifications	(11,224)	5,173
Amounts reclassified from accumulated other comprehensive loss	16,263	30,550
Total other comprehensive income	5,039	35,723	36,496
Ending balance	(48,333)	(53,372)	(89,095)
ARIZONA PUBLIC SERVICE COMPANY \| Derivative Instruments
Changes in accumulated other comprehensive income (loss) by component
Beginning balance	(23,059)	(49,592)
OCI (loss) before reclassifications	(809)	(214)
Amounts reclassified from accumulated other comprehensive loss	13,483	26,747
Total other comprehensive income	12,674	26,533
Ending balance	(10,385)	(23,059)
ARIZONA PUBLIC SERVICE COMPANY \| Pension and other postretirement benefits
Changes in accumulated other comprehensive income (loss) by component
Beginning balance	(30,313)	(39,503)
OCI (loss) before reclassifications	(10,415)	5,387
Amounts reclassified from accumulated other comprehensive loss	2,780	3,803
Total other comprehensive income	(7,635)	9,190
Ending balance	$ (37,948)	$ (30,313)

- Definition

Accumulated change in equity from transactions and other events and circumstances from non-owner sources, net of tax effect, at period end. Excludes Net Income (Loss), and accumulated changes in equity from transactions resulting from investments by owners and distributions to owners. Includes foreign currency translation items, certain pension adjustments, unrealized gains and losses on certain investments in debt and equity securities, other than temporary impairment (OTTI) losses related to factors other than credit losses on available-for-sale and held-to-maturity debt securities that an entity does not intend to sell and it is not more likely than not that the entity will be required to sell before recovery of the amortized cost basis, as well as changes in the fair value of derivatives related to the effective portion of a designated cash flow hedge.

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