Changes in Accumulated Other Comprehensive Loss (Tables)

12 Months Ended

Dec. 31, 2023

Comprehensive Income (Loss), Net of Tax, Attributable to Parent [Abstract]

Schedule of Changes in Accumulated Other Comprehensive Loss Including Reclassification Adjustments, by Component

The following table shows the changes in Pinnacle West’s consolidated accumulated other comprehensive loss, including reclassification adjustments, net of tax, by component (dollars in thousands): 

	Pension and Other Postretirement Benefits			Derivative Instruments		Total
Balance at December 31, 2021	$	(53,885)		$	(976)	$	(54,861)
OCI (loss) before reclassifications	17,550			1,873		19,423
Amounts reclassified from accumulated other comprehensive loss	4,003		(a)	—		4,003
Balance at December 31, 2022	(32,332)			897		(31,435)
OCI (loss) before reclassifications	(4,420)			713		(3,707)
Amounts reclassified from accumulated other comprehensive loss	1,998		(a)	—		1,998
Balance at December 31, 2023	$	(34,754)		$	1,610	$	(33,144)

(a)These amounts primarily represent amortization of actuarial loss and are included in the computation of net periodic pension cost. See Note 7.

The following table shows the changes in APS’s consolidated accumulated other comprehensive loss, including reclassification adjustments, net of tax, by component (dollars in thousands): 

	Pension and Other Postretirement Benefits			Total
Balance at December 31, 2021	$	(34,880)		$	(34,880)
OCI (loss) before reclassifications	15,646			15,646
Amounts reclassified from accumulated other comprehensive loss	3,638		(a)	3,638
Balance at December 31, 2022	(15,596)			(15,596)
OCI (loss) before reclassifications	(3,383)			(3,383)
Amounts reclassified from accumulated other comprehensive loss	1,760		(a)	1,760
Balance at December 31, 2023	$	(17,219)		$	(17,219)

(a)These amounts primarily represent amortization of actuarial loss and are included in the computation of net periodic pension cost. See Note 7.