Leases - Maturities of lease liabilities (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Operating leases
2019 (excluding the first 6 months)		$ 3,534
2020		5,978
2021		2,970
2022		2,426
2023		2,337
Thereafter		4,600
Total lease payments		21,845
Less imputed interest		(2,756)
Total	$ 19,089	19,089
Financing leases
2019 (excluding the first 6 months)		188
2020		346
2021		305
2022		88
2023		25
Thereafter		0
Total lease payments		952
Less imputed interest		(64)
Total	$ 888	$ 888