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Investments - Narrative (Details) - USD ($)	3 Months Ended
Investments - Narrative (Details) - USD ($)	Dec. 31, 2021	Dec. 31, 2020	Sep. 30, 2021	Feb. 05, 2021
Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Other-than-temporary impairment charges recognized	$ 0	$ 0
Realized gains (losses) from sale of available-for-sale securities	0	$ 0
Acquisition-related consideration, current	11,210,000		$ 11,050,000
Acquisition-related contingent consideration	$ 5,590,000		$ 5,720,000
2026 Notes \| Convertible Debt
Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Debt issued				$ 155,300,000
Debt interest rate				0.75%