Income Taxes - Schedule of Difference Between US Federal Statutory Income Tax Rate and Effective Income Tax Rate (Details)	12 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2020
Income Tax Disclosure [Abstract]
U.S. federal statutory income tax rate	21.00%	21.00%	21.00%
State income taxes, net of federal tax benefit	2.60%	3.00%	3.40%
Effect of foreign operations	2.20%	0.80%	(0.40%)
Valuation allowances	(7.20%)	0.60%	4.60%
Deferred tax impact of foreign branch conversion	2.70%
Unrecognized tax benefit	2.90%
Share-based payment awards	0.60%	0.60%	1.20%
Other, net		0.20%	(0.60%)
Effective tax rate	24.80%	26.20%	29.20%