Basis of Presentation and Significant Accounting Policies - Summary of Property and Equipment Balances and Estimated Useful Lives (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2020
Property Plant And Equipment [Line Items]
Total property and equipment, gross	$ 1,118,687	$ 1,074,780
Accumulated depreciation and amortization	(820,811)	(767,403)
Total property and equipment, net	297,876	307,377	$ 315,029
Land
Property Plant And Equipment [Line Items]
Total property and equipment, gross	9,949	10,119
Buildings and building improvements
Property Plant And Equipment [Line Items]
Total property and equipment, gross	56,834	57,049
Leasehold improvements
Property Plant And Equipment [Line Items]
Total property and equipment, gross	342,326	326,595
Furniture, fixtures and equipment
Property Plant And Equipment [Line Items]
Total property and equipment, gross	$ 709,578	$ 681,017
Minimum | Buildings and building improvements
Property Plant And Equipment [Line Items]
Estimated useful lives	5 years
Minimum | Leasehold improvements
Property Plant And Equipment [Line Items]
Estimated useful lives	2 years
Minimum | Furniture, fixtures and equipment
Property Plant And Equipment [Line Items]
Estimated useful lives	2 years
Maximum | Buildings and building improvements
Property Plant And Equipment [Line Items]
Estimated useful lives	40 years
Maximum | Leasehold improvements
Property Plant And Equipment [Line Items]
Estimated useful lives	10 years
Maximum | Furniture, fixtures and equipment
Property Plant And Equipment [Line Items]
Estimated useful lives	10 years