Pension and Other Postretirement Benefits (Tables)

6 Months Ended

Jun. 30, 2021

Retirement Benefits [Abstract]

Schedule of Net Benefit Costs

Pension and other postretirement benefits expenses consisted of the following:

	Three Months Ended June 30,				Six Months Ended June 30,
Pensions	2021		2020		2021		2020
Service cost	$	1,538	$	1,435	$	3,279	$	3,084
Interest cost	3,204		3,806		6,376		7,623
Expected return on plan assets	(6,962)		(7,404)		(13,934)		(14,797)
Amortization of prior service cost	80		73		165		153
Amortization of actuarial losses	4,080		3,307		8,006		6,646
Curtailment loss	—		484		—		484
Net periodic benefit cost	$	1,940	$	1,701	$	3,892	$	3,193

	Three Months Ended June 30,				Six Months Ended June 30,
Other Postretirement Benefits	2021		2020		2021		2020
Service cost	$	25	$	19	$	50	$	41
Interest cost	206		257		412		521
Amortization of prior service cost	8		7		15		14
Amortization of actuarial losses	70		(5)		140		18
Net periodic benefit cost	$	309	$	278	$	617	$	594