Stock-Based Compensation Plans - Summary of Fair Value Assumptions Used for Share Based Awards (Details) - Nonvested Stock Units - Performance Based - $ / shares	12 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2021
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average fair value per share (usd per share)	$ 35.94	$ 33.98	$ 21.81
Risk-free interest rate	4.30%	1.60%	0.20%
Expected dividend yield	0.00%	1.80%	2.30%
Expected volatility	43.00%	41.50%	42.00%
Expected term	3 years	3 years	3 years
Minimum risk free interest rate	4.24%	1.14%	0.13%
Maximum risk free interest rate	4.78%	1.88%	0.23%