Post Retirement Benefits (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Pension, health and life insurance expense:
Multi-employer plan	$ 189	$ 246
Defined contribution plan	302	293
Total pension expense	491	539
Interest cost	41	59
Amortization of prior service costs	(124)	(124)
Amortization of net loss	43	45
Net periodic benefit cost	(40)	(20)
Total post retirement benefits expense	451	$ 519
Pension Plan
Pension, health and life insurance expense:
Payments made to pension plans	201
Pension plan payments expected to be made in fiscal year	1,599
Pension plan payments accrued	774
Other Postretirement Benefits Plan
Pension, health and life insurance expense:
Payments for post retirement healthcare and life insurance	101
Pension plan payments expected to be made in fiscal year	1,185
Pension plan payments accrued	$ 1,185