Leases (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2020 USD ($) item	Mar. 31, 2019 USD ($)	Dec. 31, 2019 USD ($)
Leases
Operating lease option to extend	true
Lease expenses:
Operating leases	$ 3,932	$ 3,229
Short-term leases	256	217
Sublease income		(32)
Total lease cost	4,188	3,414
Cash payments for operating leases	4,440	3,846
Upon adoption of ASU 2016-02		58,598
New leases	1,534
Right-of-use assets obtained in exchange for lease obligations	$ 1,534	$ 58,598
Remaining lease term (in year)	6 years 10 months 24 days	6 years 3 months 18 days
Discount rate (as a percent)	4.30%	4.60%
Operating lease liabilities
2021	$ 17,111
2022	15,795
2023	14,509
2024	13,755
2025	11,643
Thereafter	32,758
Total lease payments	105,571
Less imputed interest	(15,742)
Total	$ 89,829		$ 91,320
Number of operating leases not yet commenced. | item	1
Lease expense from leases not yet commenced	$ 1,500
Minimum
Leases
Remaining operating lease term	1 year
Maximum
Leases
Remaining operating lease term	10 years
Operating lease renewal term	5 years