Segment Information - Revenues and Long-Lived Assets by Geographic Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2020
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenues	$ 886,225	$ 729,551	$ 822,777
Property and equipment, net	56,725	53,811
United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenues	658,762	553,581	638,844
Property and equipment, net	32,594	30,651
Mexico
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenues	173,122	128,773	131,965
Property and equipment, net	19,805	19,255
Other Latin America
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenues	54,230	46,777	48,146
Property and equipment, net	4,326	3,905
Canada and other
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenues	$ 111	$ 420	$ 3,822