Leases (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2023 USD ($) lease item	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)
Leases
Lessee, Operating Lease, Existence of Option to Extend [true false]	false
Operating lease liabilities	$ 11,391
Operating lease costs	13,496	$ 10,666	$ 9,723
Non-cancelable operating lease commitments not yet commenced	$ 23,758
Number of off-campus classroom and laboratory sites | item	5
Optical fiber communication lines not yet commenced	$ 192
Weighted-average remaining lease term	8 years 7 days
Weighted-average discount rate of operating leases	3.88%
Number of financing leases | lease	0
Minimum
Leases
Term of operating leases	5 months
Maximum
Leases
Term of operating leases	10 years 5 months