Pensions and other postretirement benefit plans (Tables)

3 Months Ended

Mar. 31, 2023

Retirement Benefits [Abstract]

Schedule of defined benefit plan amounts recognized in other comprehensive income (loss)

Retirement plan costs include the following components:

	Pension benefits				Postretirement benefits
	Three months ended March 31,				Three months ended March 31,
In thousands	2023		2022		2023		2022
Operating expenses:
Service cost - benefits earned during the period	$	324	$	475	$	10	$	15
Non-operating expenses:
Interest cost on benefit obligations	21,201		18,649		632		451
Expected return on plan assets	(23,668)		(37,281)		—		—
Amortization of prior service benefit	16		—		—		—
Amortization of actuarial loss (gain)	540		20		(536)		(52)
Total non-operating (benefit) expense	$	(1,911)	$	(18,612)	$	96	$	399
Total (benefit) expense for retirement plans	$	(1,587)	$	(18,137)	$	106	$	414