Leases - Maturities of operating and financing lease liabilities (Details) $ in Thousands	Mar. 31, 2019 USD ($)
Operating Leases
2019	$ 5,926
2020	6,398
2021	5,517
2022	4,775
2023	1,308
Thereafter	1,158
Total lease payments	25,082
Impact of discounting	(5,761)
Total operating lease liabilities	19,321
Current operating lease liabilities	4,151
Operating lease right-of-use liabilities, long-term portion	13,974
Noncurrent operating lease liabilities	15,170
Finance Leases
2019	17,575
2020	20,463
2021	12,156
2022	4,786
2023	595
Thereafter	55
Total lease payments	$ 55,630