Leases (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2022 USD ($) lease item	Sep. 30, 2021 USD ($)
Leases
Lessee, Operating Lease, Existence of Option to Extend [true false]	false
Operating lease costs	$ 7,596	$ 7,371
Non-cancelable operating lease commitments not yet commenced	$ 9,569
Number of off-campus classroom and laboratory sites | item	1
Weighted-average remaining lease term	8 years 2 months 19 days
Weighted-average discount rate of operating leases	3.35%
Number of financing leases | lease	0
Minimum
Leases
Term of operating leases	1 month
Maximum
Leases
Term of operating leases	10 years 9 months