Leases (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Leases
Operating lease option to extend			true
Lease expenses:
Operating leases	$ 4,034	$ 3,232	$ 7,966	$ 6,461
Short-term leases	224	214	480	431
Sublease income		(27)		(59)
Total lease cost	4,258	3,419	8,446	6,833
Cash payments for operating leases	4,354	3,884	8,794	7,730
Upon adoption of ASU 2016-02				58,598
New leases	4,964	87	6,498	115
Right-of-use assets obtained in exchange for lease obligations	$ 4,964	$ 87	$ 6,498	$ 58,713
Remaining lease term (in year)	6 years 7 months 6 days	6 years 4 months 24 days	6 years 7 months 6 days	6 years 4 months 24 days
Discount rate (as a percent)	4.20%	4.60%	4.20%	4.60%
Operating lease liabilities
2021	$ 17,995		$ 17,995
2022	16,712		16,712
2023	16,221		16,221
2024	14,851		14,851
2025	12,925		12,925
Thereafter	30,363		30,363
Total lease payments	109,067		109,067
Less imputed interest	(15,462)		(15,462)
Total	$ 93,605		$ 93,605		$ 91,320
Minimum
Leases
Remaining operating lease term			1 year
Maximum
Leases
Remaining operating lease term			10 years
Operating lease renewal term	5 years		5 years