Debt - Schedule of debt (Details) - USD ($) $ in Thousands	6 Months Ended
Mar. 28, 2020	Sep. 28, 2019
Debt Disclosure [Abstract]
Debt, interest rate	4.10%	4.60%
Debt	$ 30,000	$ 33,333
Unamortized debt issuance costs	(122)	(160)
Total indebtedness	29,878	33,173
Less short-term portion	(8,333)	(8,333)
Long-term debt	$ 21,545	$ 24,840
LIBOR
Debt Instrument [Line Items]
Interest rate, spread on variable rate	2.25%

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Percentage points added to the reference rate to compute the variable rate on the debt instrument.

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Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt.

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- Definition

Effective interest rate for the funds borrowed under the debt agreement considering interest compounding and original issue discount or premium.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Amount of unamortized debt discount (premium) and debt issuance costs.

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Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt, classified as current. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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Amount after unamortized (discount) premium and debt issuance costs of long-term debt classified as noncurrent and excluding amounts to be repaid within one year or the normal operating cycle, if longer. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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