Leases - Future minimum rental payments (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Operating Leases
2020	$ 1,226
2021	1,118
2022	1,060
2023	1,055
2024	1,106
Total lease payments	5,565
Less amount representing interest	(1,630)
Total lease obligations	3,935
2019		$ 1,180
2020		1,195
2021		1,062
2022		1,055
2023		1,055
Later years		1,106
Total lease payments		6,653
Finance Leases
2020	894
2021	117
2022	115
2023	95
2024	40
Total lease payments	1,261
Less amount representing interest	(94)
Total lease obligations	$ 1,167
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