Future minimum payments for operating leases (Details) $ in Thousands	Mar. 31, 2019 USD ($)
Commitments and Contingencies Disclosure [Abstract]
Lessee, Operating Lease, Liability, Payments, Remainder of Fiscal Year	$ 8,297
Lessee, Operating Lease, Liability, Payments, Due Year Two	9,920
Lessee, Operating Lease, Liability, Payments, Due Year Three	8,883
Lessee, Operating Lease, Liability, Payments, Due Year Four	8,256
Lessee, Operating Lease, Liability, Payments, Due Year Five	6,949
Lessee, Operating Lease, Liability, Payments, Due after Year Five	19,561
Lessee, Operating Lease, Liability, Payments, Due	61,866
Lessee, Operating Lease, Liability, Undiscounted Excess Amount	7,620
Operating Lease, Liability	$ 54,246