Acquisitions - Additional Information (Details) - USD ($)	12 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2018
Finite-Lived Intangible Assets [Line Items]
Estimated amortization period			10 years
Residual buyouts
Finite-Lived Intangible Assets [Line Items]
Intangible assets acquired	$ 1,788,000	$ 3,585,000	$ 1,567,000
Estimated amortization period	8 years	7 years	2 years
Referral agreement
Finite-Lived Intangible Assets [Line Items]
Intangible assets acquired	$ 0	$ 0	$ 815,000
Estimated amortization period	5 years