Consolidated Statements of Changes in Stockholders' Equity (Unaudited) - USD ($) $ in Thousands	Common Stock Including Additional Paid in Capital [Member]	AOCI Attributable to Parent [Member]	Retained Earnings [Member]	Total
Balance (in shares) at Sep. 28, 2019	18,895,000
Balance at Sep. 28, 2019	$ 45,744	$ (12,988)	$ 800,995	$ 833,751
Issuance of common stock upon exercise of stock options (in shares)	5,000
Issuance of common stock upon exercise of stock options	$ 468	0	0	468
Foreign currency translation adjustment	0	810	0	810
Dividends declared	0	0	(10,867)	(10,867)
Share-based compensation	1,299	0	0	1,299
Net earnings	$ 0	0	17,059	17,059
Balance (in shares) at Dec. 28, 2019	18,900,000
Balance at Dec. 28, 2019	$ 47,511	(12,178)	807,187	$ 842,520
Balance (in shares) at Sep. 26, 2020	18,915,000			18,915,000
Balance at Sep. 26, 2020	$ 49,268	(15,587)	775,817	$ 809,498
Issuance of common stock upon exercise of stock options (in shares)	41,000
Issuance of common stock upon exercise of stock options	$ 4,390	0	0	4,390
Foreign currency translation adjustment	0	2,279	0	2,279
Dividends declared	0	0	(10,900)	(10,900)
Share-based compensation	1,244	0		1,244
Net earnings	$ 0	0	1,778	$ 1,778
Balance (in shares) at Dec. 26, 2020	18,956,000			18,956,000
Balance at Dec. 26, 2020	$ 54,902	$ (13,308)	$ 766,695	$ 808,289