Stock-Based Compensation - Narrative (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
	Oct. 01, 2023	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023	Sep. 30, 2021
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock, share reserve for issuance (in shares)		4,565,727		4,565,727
Granted (in shares)				0
Stock-based compensation expense		$ 14,711	$ 19,947	$ 48,984	$ 59,949
Options
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Intrinsic value of options exercised		700	6,500	3,800	10,100
Stock-based compensation expense		400	2,100	2,500	6,700
Unrecognized pre-tax compensation expense		400		$ 400
Weighted average period to recognize pre-tax compensation expense				3 months
Restricted stock units
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense		14,300	$ 17,800	$ 46,500	$ 53,200
Weighted average period to recognize pre-tax compensation expense				1 year 7 months 6 days
Unrecognized pre-tax compensation expense		$ 96,300		$ 96,300
2013 Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares reserve for issuance (in shares)		2,924,586		2,924,586
Number of shares forfeited (in shares)				158,928
2021 Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares authorized (in shares)						8,000,000
Number of shares forfeited (in shares)				154,139
Granted (in shares)				3,697,189
Inducement Awards | Options
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares reserve for issuance (in shares)		665,020		665,020
Inducement Awards | Restricted stock units
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares reserve for issuance (in shares)		616,638		616,638
Visirna ESOP
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares authorized (in shares)	20,000,000
Granted (in shares)	7,500,000
Stock-based compensation expense		$ 2,300		$ 5,500