Employee benefit plans (Tables)

6 Months Ended

Jun. 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				Six Months Ended
	June 30,				June 30,
	2024		2023		2024		2023
	(In thousands)
Components of net periodic benefit cost (credit):
Interest cost	$	3,200	$	3,380	$	6,400	$	7,169
Expected return on assets	(4,028)		(4,299)		(8,056)		(9,048)
Amortization of net actuarial loss	1,037		773		2,074		1,674
Net periodic benefit cost (credit)	$	209	$	(146)	$	418	$	(205)

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

	Three Months Ended				Six Months Ended
	June 30,				June 30,
	2024		2023		2024		2023
	(In thousands)
Components of net periodic benefit credit:
Service cost	$	126	$	136	$	252	$	274
Interest cost	459		489		918		978
Expected return on assets	(1,329)		(1,334)		(2,658)		(2,668)
Amortization of prior service credit	(330)		(329)		(660)		(659)
Amortization of net actuarial gain	(72)		(70)		(144)		(126)
Net periodic benefit credit, including amount capitalized	(1,146)		(1,108)		(2,292)		(2,201)
Less amount capitalized	47		53		69		77
Net periodic benefit credit	$	(1,193)	$	(1,161)	$	(2,361)	$	(2,278)