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Note 11 (Details Textual) - USD ($)	3 Months Ended
	Dec. 28, 2019	Dec. 29, 2018	Sep. 28, 2019
Debt Securities, Held-to-maturity, Total	$ 118,883,000		$ 130,451,000
Proceeds from Sale and Maturity of Marketable Securities, Total	18,782,000	$ 17,125,000
Marketable Securities, Gain (Loss), Total	(11,000)	(1,027,000)
Marketable Securities, Unrealized Gain (Loss), Total	71,000	$ (1,027,000)
Corporate Bond Securities [Member]
Debt Securities, Held-to-maturity, Total	$ 106,000,000
Investment Securities Maturity Term	2 years

X

- Definition

The maturity term of investment securities in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

+ Details

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X

- Definition

Amount of investment in debt security measured at amortized cost (held-to-maturity).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 45
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=118954083&loc=d3e26610-111562

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 5
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=118939692&loc=d3e27232-111563

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X

- Definition

Amount of unrealized and realized gain (loss) on investment in marketable security, including other-than-temporary impairment (OTTI).

+ References

No definition available.

+ Details

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X

- Definition

Amount of unrealized gain (loss) on investment in marketable security.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03(7)(c))
-URI http://asc.fasb.org/extlink&oid=116634182&loc=SL114868664-224227

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X

- Definition

The cash inflow associated with the aggregate amount received by the entity through sale or maturity of marketable securities (held-to-maturity or available-for-sale) during the period.

+ References

No definition available.

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