Leases (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2019 USD ($) item	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)
Lease expenses:
Operating leases	$ 13,644
Short-term leases	821
Sublease income	(94)
Total lease cost	14,371
Cash payments for operating leases	16,167
Upon adoption of ASU 2016-02	58,713
New leases	24,535
Right-of-use assets obtained in exchange for lease obligations	$ 83,248
Remaining lease term (in year)	7 years 1 month 6 days
Discount rate (as a percent)	4.30%
Lease expense	$ 14,400	$ 12,300	$ 12,300
Operating lease liabilities
2020	17,102
2021	16,051
2022	13,791
2023	14,006
2024	11,673
Thereafter	35,178
Total lease payments	107,801
Less imputed interest	(16,481)
Total	$ 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 option to extend	false