Debt and Capital Leases (Narrative) (Details) - USD ($)	3 Months Ended				12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Sep. 24, 2019	Sep. 25, 2018
Debt Instrument [Line Items]
Interest expense					$ 756,000	$ 392,000
Cadence Credit Facility [Member]
Debt Instrument [Line Items]
Loan Agreement, amount					17,000,000
Loan Agreement, amount outstanding					$ 12,850,000
Interest rate					0.25%
Weighted average interest rate					5.6733%
Interest rate description					All borrowings under the Cadence Credit Facility, as amended, bear interest at a variable rate based upon the Company’s election of (i) 2.5% plus the base rate, which is the highest of the (a) Federal Funds Rate plus 0.5%, (b) the Cadence bank publicly-announced prime rate, and (c) LIBOR plus 1.0%, or (ii) LIBOR, with a 0.250% floor, plus 3.5%. Interest is due at the end of each calendar quarter if the Company selects to pay interest based on the base rate and at the end of each LIBOR period if it selects to pay interest based on LIBOR.
Payment of debt issuance costs					$ 232,000
Maturity date					Dec. 31, 2021
Minimum liquidity amount					$ 2,000,000
Letters of credit outstanding, amount					$ 157,500
Credit Agreement [Member] | Subsequent Event [Member]
Debt Instrument [Line Items]
Repayment of certain loans outstanding	$ 250,000	$ 250,000	$ 250,000	$ 250,000