Leases - Future minimum payments for finance and operating leases (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Finance leases
2021	$ 251
2022	251
2023	21
Total future minimum lease payments	523
Amounts representing interest	(39)
Total finance lease liabilities	484	$ 640
Operating leases
2021	2,179
2022	2,095
2023	1,832
2024	1,065
2025	707
Thereafter	1,753
Total future minimum lease payments	9,631
Amounts representing interest	(960)
Total operating lease liabilities	$ 8,671	$ 8,864