Leases - Maturities of lease liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Operating leases
2019 (excluding the first 9 months)		$ 1,778
2020		6,454
2021		3,562
2022		2,892
2023		2,711
Thereafter		4,987
Total lease payments		22,384
Less imputed interest		(2,676)
Total	$ 19,708	19,708
Financing leases
2019 (excluding the first 9 months)		94
2020		351
2021		312
2022		86
2023		37
Thereafter		6
Total lease payments		886
Less imputed interest		(57)
Total	$ 829	$ 829