Changes in Accumulated Other Comprehensive Loss (Tables)

12 Months Ended

Dec. 31, 2024

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, 2022	$	(32,332)		$	897	$	(31,435)
Other comprehensive income/(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)
Other comprehensive income/(loss) before reclassifications	1,039			(891)		148
Amounts reclassified from accumulated other comprehensive loss	2,054		(a)	—		2,054
Balance at December 31, 2024	$	(31,661)		$	719	$	(30,942)

(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
Balance at December 31, 2022	$	(15,596)
Other comprehensive (loss) before reclassifications	(3,383)
Amounts reclassified from accumulated other comprehensive loss	1,760		(a)
Balance at December 31, 2023	(17,219)
Other comprehensive income before reclassifications	1,255
Amounts reclassified from accumulated other comprehensive loss	1,848		(a)
Balance at December 31, 2024	$	(14,116)

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