Line of Credit (Details) - USD ($) $ in Thousands		12 Months Ended
	May 26, 2016	Sep. 30, 2019	Sep. 30, 2018	Oct. 04, 2017
Letter of Credit
Line of Credit Facility [Line Items]
Line of credit, expiration date		Oct. 04, 2022
Letter of Credit | Minimum
Line of Credit Facility [Line Items]
Line of credit, expiration period		90 days
Line of Credit | Credit Agreement | Revolving Credit Facility
Line of Credit Facility [Line Items]
Debt instrument, term (in years)	5 years
Line of credit, maximum borrowing capacity	$ 75,000			$ 75,000
Outstanding line of credit		$ 0	$ 0
Deferred finance costs		$ 400	$ 500
Line of Credit | Credit Agreement | Letter of Credit
Line of Credit Facility [Line Items]
Line of credit, maximum borrowing capacity	25,000
Line of Credit | Credit Agreement | Swing Loan
Line of Credit Facility [Line Items]
Line of credit, maximum borrowing capacity	$ 7,500			7,500
Secured Debt | Senior Secured Term Loan Facility
Line of Credit Facility [Line Items]
Face amount				$ 200,000