Changes in Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Changes in accumulated other comprehensive income (loss) by component
Beginning balance	$ (68,141)	$ (78,053)
Total other comprehensive income	23,393	9,912	$ 35,955
Ending balance	(44,748)	(68,141)	(78,053)
Derivative Instruments
Changes in accumulated other comprehensive income (loss) by component
OCI (loss) before reclassifications	(957)	(810)
Amounts reclassified from accumulated other comprehensive loss	4,187	13,483
Total other comprehensive income	3,230	12,673
Pension and Other Postretirement Benefits
Changes in accumulated other comprehensive income (loss) by component
OCI (loss) before reclassifications	16,980	(5,419)
Amounts reclassified from accumulated other comprehensive loss	3,183	2,658
Total other comprehensive income	20,163	(2,761)
ARIZONA PUBLIC SERVICE COMPANY
Changes in accumulated other comprehensive income (loss) by component
Beginning balance	(48,333)	(53,372)
Total other comprehensive income	21,236	5,039	35,723
Ending balance	(27,097)	(48,333)	$ (53,372)
ARIZONA PUBLIC SERVICE COMPANY \| Derivative Instruments
Changes in accumulated other comprehensive income (loss) by component
OCI (loss) before reclassifications	(957)	(809)
Amounts reclassified from accumulated other comprehensive loss	4,187	13,483
Total other comprehensive income	3,230	12,674
ARIZONA PUBLIC SERVICE COMPANY \| Pension and Other Postretirement Benefits
Changes in accumulated other comprehensive income (loss) by component
OCI (loss) before reclassifications	14,726	(10,415)
Amounts reclassified from accumulated other comprehensive loss	3,280	2,780
Total other comprehensive income	$ 18,006	$ (7,635)

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.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
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-Name Accounting Standards Codification
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-SubTopic 10
-Section 45
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-URI http://asc.fasb.org/extlink&oid=36458714&loc=d3e637-108580

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