Credit Facilities - Narrative (Details)	9 Months Ended
	Jun. 30, 2020 USD ($)	Sep. 30, 2019 USD ($)
Interest Rate Swap
Line of Credit Facility [Line Items]
Derivative notional amount		$ 36,000,000
Derivative fixed interest rate		1.61%
Interest expense increase (less than)	$ 100,000
Secured Debt | Term Loans
Line of Credit Facility [Line Items]
Secured term loan, face amount	$ 70,000,000
Required amortization percentage in year 1	7.50%
Required amortization percentage in year 2	7.50%
Required amortization percentage in year 3	10.00%
Required amortization percentage in year 4	10.00%
Required amortization percentage in year 5	12.50%
Fixed charge coverage ratio	1.25
Ratio of funded indebtedness to EBITDA through maturity	3.25
Debt quarterly installment payments	$ 1,312,500
Period of frequency to increase quarterly installment payments	2 years
Increase in quarterly periodic payments	$ 437,500
Secured Debt | Term Loans | Excess Cash Flows Greater Than Or Equal to 2.50
Line of Credit Facility [Line Items]
Percentage of excess cash flow for each year of funded indebtedness to EBDTA	75.00%
Ratio of funded indebtedness to adjusted EBDTA, actual	2.50
Secured Debt | Term Loans | Excess Cash Flows Less Than 2.50 [Member]
Line of Credit Facility [Line Items]
Percentage of excess cash flow for each year of funded indebtedness to EBDTA	50.00%
Secured Debt | Term Loans | Excess Cash Flows Equal to 1.50
Line of Credit Facility [Line Items]
Ratio of funded indebtedness to adjusted EBDTA, actual	1.5
Secured Debt | Term Loans | Excess Cash Flows Less Than 1.50
Line of Credit Facility [Line Items]
Percentage of excess cash flow for each year of funded indebtedness to EBDTA	0.00%
Ratio of funded indebtedness to adjusted EBDTA, actual	1.5
Secured Debt | Term Loans | Maximum
Line of Credit Facility [Line Items]
Ratio of funded indebtedness to EBITDA through maturity	4.25
Secured Debt | Term Loans | Maximum | Excess Cash Flows Less Than 2.50 [Member]
Line of Credit Facility [Line Items]
Ratio of funded indebtedness to adjusted EBDTA, actual	2.50
Secured Debt | Term Loans | LIBOR
Line of Credit Facility [Line Items]
Interest rate spread	0.17%
Secured Debt | Term Loans | LIBOR | Maximum
Line of Credit Facility [Line Items]
Interest rate spread	4.50%
Secured Debt | Term Loans | LIBOR | Minimum
Line of Credit Facility [Line Items]
Interest rate spread	2.50%
Secured Debt | Revolving Line of Credit
Line of Credit Facility [Line Items]
Line of credit, maximum borrowing capacity	$ 25,000,000.0
Line of credit, current borrowing capacity	19,300,000
Secured Debt | Letter of Credit
Line of Credit Facility [Line Items]
Line of credit, current borrowing capacity	$ 3,000,000