Employee Benefit Plans - Expense (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Summary of employee benefits charged to operating expenses
Payroll taxes	$ 389	$ 346
Medical plans	427	450
401k match and profit sharing	306	276
Periodic pension cost	464	379
Other	23	15
Total employee benefits	$ 1,609	$ 1,466