Pension and Other Post-Employment Benefits (Tables)

3 Months Ended

Mar. 31, 2020

Compensation And Retirement Disclosure [Abstract]

Schedule of Net Periodic Benefit Costs

The following tables summarize the components of net periodic benefit costs.  Service costs incurred for plant personnel are included in cost of goods sold.  Service costs incurred for corporate personnel and retirees are included in selling, general, and administrative expenses.  All other components of net period benefit cost are included in other non-operating expense, net on the Condensed Consolidated Statements of Loss, for the three months ended March 31, 2020 and 2019 as follows:

	Covia Pension Plan
	Three Months Ended March 31,
	2020			2019
	(in thousands)
Components of net periodic benefit cost
Service cost	$	126		$	551
Interest cost		971			2,084
Expected return on plan assets		(1,263	)		(2,308	)
Amortization of prior service cost		27			82
Amortization of net actuarial loss		476			522
Settlement loss		2,011			1,679
Net periodic benefit cost	$	2,348		$	2,610

	Postretirement Medical Plans
	Three Months Ended March 31,
	2020		2019
	(in thousands)
Components of net periodic benefit cost
Service cost	$	79	$	73
Interest cost		35		120
Amortization of net actuarial loss		15		40
Net periodic benefit cost	$	129	$	233