Lease Obligations - Schedule of future minimum lease payments (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Capital Lease Obligations
2019	$ 1,185
2020	1,185
2021	365
2022	0
2023	0
Thereafter	0
Total minimum lease payments	2,735
Interest	(102)
Net present of minimum lease payments	2,633
Less: Current portion of capital lease obligations	1,119	$ 1,086
Long-term capital lease obligations	1,514	$ 2,629
Operating Lease Obligations
2019	4,829
2020	3,754
2021	2,971
2022	2,379
2023	1,335
Thereafter	2,127
Total minimum lease payments	$ 17,395