Employee benefit plans (Tables)

9 Months Ended

Sep. 30, 2024

Retirement Benefits [Abstract]

Schedule of net benefit costs

Components of net periodic benefit cost (credit) for the Company's pension benefit plans were as follows:

	Three Months Ended				Nine Months Ended
	September 30,				September 30,
	2024		2023		2024		2023
	(In thousands)
Components of net periodic benefit cost (credit):
Interest cost	$	3,200	$	3,380	$	9,600	$	10,140
Expected return on assets	(4,028)		(4,299)		(12,084)		(12,897)
Amortization of net actuarial loss	1,037		773		3,111		2,319
Net periodic benefit cost (credit)	$	209	$	(146)	$	627	$	(438)

Components of net periodic benefit credit for the Company's other postretirement benefit plans were as follows:

	Three Months Ended				Nine Months Ended
	September 30,				September 30,
	2024		2023		2024		2023
	(In thousands)
Components of net periodic benefit credit:
Service cost	$	126	$	131	$	378	$	405
Interest cost	459		489		1,377		1,467
Expected return on assets	(1,329)		(1,334)		(3,987)		(4,026)
Amortization of prior service credit	(330)		(330)		(990)		(989)
Amortization of net actuarial gain	(72)		(96)		(216)		(408)
Net periodic benefit credit, including amount capitalized	(1,146)		(1,140)		(3,438)		(3,551)
Less amount capitalized	25		23		72		76
Net periodic benefit credit	$	(1,171)	$	(1,163)	$	(3,510)	$	(3,627)