Employee Benefit Plans - Expense (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Summary of employee benefits charged to operating expenses
Payroll taxes	$ 346	$ 351
Medical plans	450	548
401k match and profit sharing	276	186
Periodic pension cost	379	405
Other	15	15
Total employee benefits	$ 1,466	$ 1,505