Leases (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2019 USD ($) renewal_option	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)	Jun. 30, 2019 USD ($)
Lessee, Lease, Description [Line Items]
Rent expense		$ 5,600	$ 4,700
Lease, Cost [Abstract]
Operating lease cost	$ 3,544
Short-term lease cost	1,324
Variable lease cost	923
Lease cost	5,791
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash flows from operating leases	4,018
Right-of-use assets obtained in exchange for lease obligations: Operating leases	$ 2,207
Weighted Average Remaining Lease Term (in years) - Operating leases	7 years 7 months 6 days
Weighted Average Discount Rate - Operating leases	5.70%
Lessee, Operating Lease, Liability, Payment, Due [Abstract]
2020	$ 4,198
2021	4,327
2022	3,872
2023	3,540
2024	2,751
Thereafter	8,504
Total minimum lease payments	27,192
Less: Amount representing interest	(5,564)
Total	$ 21,628
Office
Lessee, Lease, Description [Line Items]
Number of renewal options (or more) | renewal_option	1
Office | Minimum
Lessee, Lease, Description [Line Items]
Renewal term	3 years
Office | Maximum
Lessee, Lease, Description [Line Items]
Renewal term	5 years
Amsterdam office space lease
Lessee, Lease, Description [Line Items]
Operating lease term				3 years
Monthly operating lease payment				$ 73