Investments - Summary of Fair Values of Investments Measured on Recurring Basis (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Sep. 30, 2019
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments at fair value	$ 40,035	$ 16,502
Total assets at fair value	41,998	18,054
Acquisition-related contingent consideration	753	1,601
Total liabilities at fair value	753	1,601
U.S. Treasury
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments at fair value	10,283	4,242
Long-term investments at fair value	0	1,101
Asset-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments at fair value	4,759
Long-term investments at fair value	0
Corporate debt securities | Financial
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments at fair value	7,695	2,503
Long-term investments at fair value	977	451
Corporate debt securities | Industrial
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments at fair value	1,924	1,371
Long-term investments at fair value	986	0
Commercial paper | Financial
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments at fair value	13,479	5,560
Commercial paper | Industrial
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments at fair value	1,895	2,826
Quoted Prices in Active Markets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments at fair value	10,283	4,242
Total assets at fair value	10,283	5,343
Acquisition-related contingent consideration	0	0
Total liabilities at fair value	0	0
Quoted Prices in Active Markets (Level 1) | U.S. Treasury
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments at fair value	10,283	4,242
Long-term investments at fair value	0	1,101
Quoted Prices in Active Markets (Level 1) | Asset-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments at fair value	0
Long-term investments at fair value	0
Quoted Prices in Active Markets (Level 1) | Corporate debt securities | Financial
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments at fair value	0	0
Long-term investments at fair value	0	0
Quoted Prices in Active Markets (Level 1) | Corporate debt securities | Industrial
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments at fair value	0	0
Long-term investments at fair value	0	0
Quoted Prices in Active Markets (Level 1) | Commercial paper | Financial
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments at fair value	0	0
Quoted Prices in Active Markets (Level 1) | Commercial paper | Industrial
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments at fair value	0	0
Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments at fair value	29,752	12,260
Total assets at fair value	31,715	12,711
Acquisition-related contingent consideration	0	0
Total liabilities at fair value	0	0
Significant Other Observable Inputs (Level 2) | U.S. Treasury
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments at fair value	0	0
Long-term investments at fair value	0	0
Significant Other Observable Inputs (Level 2) | Asset-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments at fair value	4,759
Long-term investments at fair value	0
Significant Other Observable Inputs (Level 2) | Corporate debt securities | Financial
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments at fair value	7,695	2,503
Long-term investments at fair value	977	451
Significant Other Observable Inputs (Level 2) | Corporate debt securities | Industrial
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments at fair value	1,924	1,371
Long-term investments at fair value	986	0
Significant Other Observable Inputs (Level 2) | Commercial paper | Financial
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments at fair value	13,479	5,560
Significant Other Observable Inputs (Level 2) | Commercial paper | Industrial
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments at fair value	1,895	2,826
Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments at fair value	0	0
Total assets at fair value	0	0
Acquisition-related contingent consideration	753	1,601
Total liabilities at fair value	753	1,601
Significant Unobservable Inputs (Level 3) | U.S. Treasury
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments at fair value	0	0
Long-term investments at fair value	0	0
Significant Unobservable Inputs (Level 3) | Asset-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments at fair value	0
Long-term investments at fair value	0
Significant Unobservable Inputs (Level 3) | Corporate debt securities | Financial
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments at fair value	0	0
Long-term investments at fair value	0	0
Significant Unobservable Inputs (Level 3) | Corporate debt securities | Industrial
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments at fair value	0	0
Long-term investments at fair value	0	0
Significant Unobservable Inputs (Level 3) | Commercial paper | Financial
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments at fair value	0	0
Significant Unobservable Inputs (Level 3) | Commercial paper | Industrial
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments at fair value	$ 0	$ 0