Note 11 - Held-to-maturity Securities by Contractual Maturity (Details) - USD ($) $ in Thousands	Dec. 26, 2020	Sep. 26, 2020
Due in one year or less, amortized cost	$ 34,286	$ 51,151
Due in one year or less, fair market value	34,745	51,815
Due after one year through five years, amortized cost	8,595	16,927
Due after one year through five years, fair market value	8,727	17,246
Due after five years through ten years, amortized cost	0	0
Due after five years through ten years, fair market value	0	0
Total held to maturity securities, amortized cost	42,881	68,078
Total held to maturity securities, fair market value	43,472	69,061
Less current portion, amortized cost	34,286	51,151
Less current portion, fair market value	34,745	51,815
Long term held to maturity securities, amortized cost	8,595	16,927
Long term held to maturity securities, fair market value	$ 8,727	$ 17,246

The current portion of fair value of investments in debt securities classified as held-to-maturity.

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The non-current portion of fair value of investments in debt securities classified as held-to-maturity.

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

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

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Fair value of investment in debt security measured at amortized cost (held-to-maturity), with single maturity date and allocated without single maturity date, maturing in sixth through tenth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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Amount of investment in debt security measured at amortized cost (held-to-maturity), with single maturity date and allocated without single maturity date, maturing in sixth through tenth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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Fair value of investment in debt security measured at amortized cost (held-to-maturity), with single maturity date and allocated without single maturity date, maturing in second through fifth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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Fair value of investment in debt security measured at amortized cost (held-to-maturity), with single maturity date and allocated without single maturity date, maturing in next fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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Amount of investment in debt security measured at amortized cost (held-to-maturity), with single maturity date and allocated without single maturity date, maturing in next fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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

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