Changes in Fair Value of Company Level 3 Financial Instruments (Details) - Nonrecurring - Significant Unobservable (Level 3) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Balance	$ 9,940	$ 7,713
Business acquisition		4,342
Fair value adjustments	1,100	(2,115)
Payment of contingent consideration	(78)
Balance	$ 10,962	$ 9,940