Leases - Future lease payments (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Operating leases
2020	$ 7,691
2021	6,291
2022	3,967
2023	3,072
2024	2,453
Thereafter	7,163
Total undiscounted lease payments	30,637
Less: effects of discounting	(3,617)
Present value of lease payments	27,020
Finance leases
2020	7,434
2021	3,438
2022	768
2023	4
Total undiscounted lease payments	11,644
Less: effects of discounting	(999)
Present value of lease payments	$ 10,645
Operating leases under ASC 840
2019		$ 6,638
2020		4,618
2021		3,487
2022		2,195
2023		1,426
Thereafter		3,339
Total		21,703
Capital Leases under ASC 840
2019		8,740
2020		6,790
2021		2,533
2022		41
Total		$ 18,104