Leases - Future annual minimum lease payments and finance lease commitments (Details) $ in Thousands	Mar. 31, 2019 USD ($)
Operating Leases
2019 (remaining nine months)	$ 11,240
2020	14,301
2021	12,022
2022	10,308
2023	9,715
2024 and thereafter	46,917
Total minimum lease payments	104,503
Finance Lease, Liability, Payment, Due [Abstract]
2019 (remaining nine months)	1,316
2020	1,781
2021	1,816
2022	1,853
2023	465
2024 and thereafter	0
Total minimum lease payments	$ 7,231