Pension plans and other postretirement benefits (Tables)

3 Months Ended

Mar. 31, 2023

Compensation And Retirement Disclosure [Abstract]

Net Periodic Defined Benefit Cost for Defined Benefit Plans

The Company provides defined benefit pension and other postretirement benefits (including health care and life insurance benefits) to qualified retired employees. Net periodic defined benefit cost for defined benefit plans consisted of the following:

	Pension Benefits						Other Postretirement Benefits
	Three Months Ended March 31
	2023			2022			2023			2022
	(In thousands)
Service cost	$	2,723		$	4,271		$	390		$	232
Interest cost on projected benefit obligation		28,835			16,267			744			355
Expected return on plan assets		(50,400	)		(37,150	)		—			—
Amortization of prior service cost (credit)		50			125			(525	)		(1,075	)
Amortization of net actuarial loss (gain)		(900	)		4,625			(650	)		(325	)
Net periodic cost (benefit)	$	(19,692	)	$	(11,862	)	$	(41	)	$	(813	)