Note 11 - Held-to-maturity Securities by Contractual Maturity (Details) - USD ($) $ in Thousands	Mar. 28, 2020	Sep. 28, 2019
Due in one year or less, amortized cost	$ 69,337	$ 51,091
Due in one year or less, fair market value	69,410	51,325
Due after one year through five years, amortized cost	41,091	79,360
Due after one year through five years, fair market value	40,699	80,300
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	110,428	130,451
Total held to maturity securities, fair market value	110,109	131,625
Less current portion, amortized cost	69,337	51,091
Less current portion, fair market value	69,410	51,325
Long term held to maturity securities, amortized cost	41,091	79,360
Long term held to maturity securities, fair market value	$ 40,699	$ 80,300