Nature of Operations and Summary of Significant Accounting Policies - Potentially Dilutive Common Stocks Excluded From Computation of Basic and Diluted Net Income (Loss) Per Share (Details) - shares shares in Thousands	12 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2020
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total potentially dilutive common shares outstanding (in shares)	17,273	11,753	1,804
Stock options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total potentially dilutive common shares outstanding (in shares)	506	543	239
RSUs
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total potentially dilutive common shares outstanding (in shares)	960	1,113	1,519
ESPP common stock equivalents
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total potentially dilutive common shares outstanding (in shares)	7	9	14
Performance options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total potentially dilutive common shares outstanding (in shares)	623	272	0
Performance RSUs
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total potentially dilutive common shares outstanding (in shares)	281	104	32
Convertible senior notes
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total potentially dilutive common shares outstanding (in shares)	7,448	4,856	0
Warrants
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total potentially dilutive common shares outstanding (in shares)	7,448	4,856	0