Stockholders' Equity - Summary of Antidilutive Securities Excluded From Calculation (Details) - shares shares in Thousands	12 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2023
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Antidilutive securities excluded from computation of diluted weighted average shares (in shares)	800	2,037	2,032
Restricted stock units
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Antidilutive securities excluded from computation of diluted weighted average shares (in shares)	347	577	598
Employee stock purchase plan
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Antidilutive securities excluded from computation of diluted weighted average shares (in shares)	7	30	4
Class B Common Stock
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Antidilutive securities excluded from computation of diluted weighted average shares (in shares)	446	1,430	1,430