INVESTMENTS - Summary of Fair Value of Investments Measured on Recurring Basis (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Sep. 30, 2023
Assets:
Short-term investments:	$ 59,373	$ 74,700
Long-term investments:		1,304
Total assets at fair value	59,373	76,004
Liabilities:
Acquisition-related contingent consideration	0	7,976
Total liabilities at fair value		7,976
U.S. Treasury
Assets:
Short-term investments:	31,687	40,254
Long-term investments:		1,304
Commercial paper
Assets:
Short-term investments:	18,622
Corporate debt securities
Assets:
Short-term investments:	9,064	34,446
Quoted Prices in Active Markets (Level 1)
Assets:
Short-term investments:	31,687	40,254
Long-term investments:		1,304
Total assets at fair value	31,687	41,558
Liabilities:
Acquisition-related contingent consideration		0
Total liabilities at fair value		0
Quoted Prices in Active Markets (Level 1) | U.S. Treasury
Assets:
Short-term investments:	31,687	40,254
Long-term investments:		1,304
Quoted Prices in Active Markets (Level 1) | Commercial paper
Assets:
Short-term investments:	0
Quoted Prices in Active Markets (Level 1) | Corporate debt securities
Assets:
Short-term investments:	0	0
Significant Other Observable Inputs (Level 2)
Assets:
Short-term investments:	27,686	34,446
Long-term investments:		0
Total assets at fair value	27,686	34,446
Liabilities:
Acquisition-related contingent consideration		0
Total liabilities at fair value		0
Significant Other Observable Inputs (Level 2) | U.S. Treasury
Assets:
Short-term investments:	0	0
Long-term investments:		0
Significant Other Observable Inputs (Level 2) | Commercial paper
Assets:
Short-term investments:	18,622
Significant Other Observable Inputs (Level 2) | Corporate debt securities
Assets:
Short-term investments:	9,064	34,446
Significant Unobservable Inputs (Level 3)
Assets:
Short-term investments:	0	0
Long-term investments:		0
Total assets at fair value	0	0
Liabilities:
Acquisition-related contingent consideration		7,976
Total liabilities at fair value		7,976
Significant Unobservable Inputs (Level 3) | U.S. Treasury
Assets:
Short-term investments:	0	0
Long-term investments:		0
Significant Unobservable Inputs (Level 3) | Commercial paper
Assets:
Short-term investments:	0
Significant Unobservable Inputs (Level 3) | Corporate debt securities
Assets:
Short-term investments:	$ 0	$ 0