Pension and Other Postretirement Benefit Costs (Tables)

6 Months Ended

Jun. 30, 2017

Pension and Other Postretirement Benefit Expense [Abstract]

Schedule of Net Benefit Costs

The following table provides the components of net periodic benefit cost for our pension and other postretirement benefit plans:

	Three Months Ended June 30,												Six Months Ended June 30,
	Pension Benefits						Other Postretirement Benefits						Pension Benefits						Other Postretirement Benefits
In thousands	2017			2016			2017			2016			2017			2016			2017			2016
Service cost	$	1,870		$	1,944		$	99		$	121		$	3,740		$	3,888		$	197		$	242
Interest cost	4,472			4,574			274			300			8,944			9,148			548			600
Expected return on plan assets	(5,112		)	(5,017		)	—			—			(10,225		)	(10,034		)	—			—
Amortization of prior service costs	31			58			(117		)	(117		)	63			116			(234		)	(234		)
Amortization of net actuarial loss	3,622			3,502			139			192			7,243			7,004			277			384
Net periodic benefit cost	4,883			5,061			395			496			9,765			10,122			788			992
Amount allocated to construction	(1,558		)	(1,574		)	(135		)	(164		)	(3,079		)	(3,122		)	(267		)	(328		)
Amount deferred to regulatory balancing account(1)	(1,508		)	(1,593		)	—			—			(3,035		)	(3,220		)	—			—
Net amount charged to expense	$	1,817		$	1,894		$	260		$	332		$	3,651		$	3,780		$	521		$	664

⁽¹⁾ The deferral of defined benefit pension plan expenses above or below the amount set in rates was approved by the OPUC, with recovery of these deferred amounts through the implementation of a balancing account. The balancing account includes the expectation of higher net periodic benefit costs than costs recovered in rates in the near-term with lower net periodic benefit costs than costs recovered in rates expected in future years. Deferred pension expense balances include accrued interest at the utility’s authorized rate of return, with the equity portion of the interest recognized when amounts are collected in rates. See Note 2 in the 2016 Form 10-K.

Schedule of Amounts Recognized in Other Comprehensive Income (Loss)

The following table presents amounts recognized in accumulated other comprehensive loss (AOCL) and the changes in AOCL related to our non-qualified employee benefit plans:

	Three Months Ended June 30,						Six Months Ended June 30,
In thousands	2017			2016			2017			2016
Beginning balance	$	(6,815	)	$	(6,968	)	$	(6,951	)	$	(7,162	)
Amounts reclassified to AOCL	—			—			—			—
Amounts reclassified from AOCL:
Amortization of actuarial losses	225			269			450			590
Total reclassifications before tax	225			269			450			590
Tax (benefit) expense	(88		)	(126		)	(177		)	(253		)
Total reclassifications for the period	137			143			273			337
Ending balance	$	(6,678	)	$	(6,825	)	$	(6,678	)	$	(6,825	)