Leases - Future minimum rental payments (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Operating Leases
2019	$ 587
2020	1,225
2021	1,118
2022	1,060
2023	1,055
Later years	1,106
Total lease payments	6,151
2019		$ 1,180
2020		1,195
2021		1,062
2022		1,055
2023		1,055
Later years		1,106
Total lease payments		6,653
Less amount representing interest	(1,937)
Total lease obligations	4,214
Finance Leases
2019	677
2020	893
2021	117
2022	115
2023	95
Later years	40
Total lease payments	1,937
Less amount representing interest	(187)
Total lease obligations	$ 1,750
2019		1,257
2020		798
2021		21
2022		20
Minimum lease commitment		2,096
Less amount representing interest		(238)
Present value of net minimum lease obligations		$ 1,858