Changes in Fair Value of Company Level 3 Financial Instruments (Details) - Nonrecurring - Significant Unobservable (Level 3) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Balance	$ 10,962	$ 9,940
Fair value adjustments	(3,524)	1,100
Payment of contingent consideration	(1,421)	(78)
Contingent consideration	6,017
Less: Consideration payable	(807)
Balance	$ 5,210	$ 10,962