v3.26.1
Leases - Narrative (Details)
$ in Millions
 9 Months Ended
Jun. 30, 2026
USD ($)
campus
Lessee, Lease, Description [Line Items]  
Number of lease contracts 32
Number of leasable campuses 34
Number of other locations under non-cancelable operating leases 3
Operating Lease, Lease Not yet Commenced, One  
Lessee, Lease, Description [Line Items]  
Lease not yet commenced amount | $ $ 50.1
Minimum  
Lessee, Lease, Description [Line Items]  
Lease term 5 years
Minimum | Operating Lease, Lease Not yet Commenced, One  
Lessee, Lease, Description [Line Items]  
Term of lease not yet commenced 11 years
Maximum  
Lessee, Lease, Description [Line Items]  
Lease term 20 years
Maximum | Operating Lease, Lease Not yet Commenced, One  
Lessee, Lease, Description [Line Items]  
Term of lease not yet commenced 15 years