Changes in Accumulated Other Comprehensive Loss (Tables)

9 Months Ended

Sep. 30, 2020

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

Schedule of changes in accumulated other comprehensive loss including reclassification adjustments, net of tax, 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
Three Months Ended September 30
Balance June 30, 2020	$	(56,326)		$	(1,549)		$	(57,875)
OCI (loss) before reclassifications	—			(659)			(659)
Amounts reclassified from accumulated other comprehensive loss	1,043		(a)	—			1,043
Balance September 30, 2020	$	(55,283)		$	(2,208)		$	(57,491)
Balance June 30, 2019	$	(46,657)		$	(979)		$	(47,636)
Amounts reclassified from accumulated other comprehensive loss	880		(a)	218		(b)	1,098
Balance September 30, 2019	$	(45,777)		$	(761)		$	(46,538)

	Pension and Other Postretirement Benefits			Derivative Instruments			Total
Nine Months Ended September 30
Balance December 31, 2019	$	(56,522)		$	(574)		$	(57,096)
OCI (loss) before reclassifications	(2,008)			(1,916)			(3,924)
Amounts reclassified from accumulated other comprehensive loss	3,247		(a)	282		(b)	3,529
Balance September 30, 2020	$	(55,283)		$	(2,208)		$	(57,491)
Balance December 31, 2018	$	(45,997)		$	(1,711)		$	(47,708)
OCI (loss) before reclassifications	(2,422)			—			(2,422)
Amounts reclassified from accumulated other comprehensive loss	2,642		(a)	950		(b)	3,592
Balance September 30, 2019	$	(45,777)		$	(761)		$	(46,538)

(a)    These amounts primarily represent amortization of actuarial loss and are included in the computation of net periodic pension cost.  See Note 5.

(b)    These amounts primarily represent realized gains and losses and are included in the computation of fuel and purchased power costs and are subject to the PSA.  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 for the three and nine months ended September 30, 2020 and 2019 (dollars in thousands): 

	Pension and Other Postretirement Benefits			Derivative Instruments			Total
Three Months Ended September 30
Balance June 30, 2020	$	(35,025)		$	—		$	(35,025)
Amounts reclassified from accumulated other comprehensive loss	900		(a)	—			900
Balance September 30, 2020	$	(34,125)		$	—		$	(34,125)
Balance June 30, 2019	$	(26,297)		$	(979)		$	(27,276)
Amounts reclassified from accumulated other comprehensive loss	755		(a)	218		(b)	973
Balance September 30, 2019	$	(25,542)		$	(761)		$	(26,303)

	Pension and Other Postretirement Benefits			Derivative Instruments			Total
Nine Months Ended September 30
Balance December 31, 2019	$	(34,948)		$	(574)		$	(35,522)
OCI (loss) before reclassifications	(1,951)			292			(1,659)
Amounts reclassified from accumulated other comprehensive loss	2,774		(a)	282		(b)	3,056
Balance September 30, 2020	$	(34,125)		$	—		$	(34,125)
Balance December 31, 2018	$	(25,396)		$	(1,711)		$	(27,107)
OCI (loss) before reclassifications	(2,414)			—			(2,414)
Amounts reclassified from accumulated other comprehensive loss	2,268		(a)	950		(b)	3,218
Balance September 30, 2019	$	(25,542)		$	(761)		$	(26,303)

(a)    These amounts primarily represent amortization of actuarial loss and are included in the computation of net periodic pension cost.  See Note 5.

(b)    These amounts primarily represent realized gains and losses and are included in the computation of fuel and purchased power costs and are subject to the PSA.  See Note 7.