Fair Value of Financial Instruments - Changes in Fair Value of Company Level 3 Financial Instruments (Details) - Nonrecurring - Significant Unobservable (Level 3) - USD ($) $ in Thousands	6 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Balance	$ 6,017	$ 10,962
Fair value adjustments	(4,658)	(918)
Payment of contingent consideration	(807)
Balance	$ 552	$ 10,044