Lease Obligations Future lease payments (Details) $ in Thousands	Dec. 31, 2018 USD ($)
Leases [Abstract]
Operating Leases, Future Minimum Payments Due, Next Twelve Months	$ 2,300
Operating Leases, Future Minimum Payments, Due in Two Years	1,998
Operating Leases, Future Minimum Payments, Due in Three Years	1,800
Operating Leases, Future Minimum Payments, Due in Four Years	1,689
Operating Leases, Future Minimum Payments, Due in Five Years	1,642
Operating Leases, Future Minimum Payments, Due Thereafter	5,400
Operating Leases, Future Minimum Payments Due	$ 14,800