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. 26, 2020	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	0	1,244
Net earnings	$ 0	0	1,778	1,778
Balance (in shares) at Dec. 26, 2020	18,956,000
Balance at Dec. 26, 2020	$ 54,902	(13,308)	766,695	808,289
Balance (in shares) at Sep. 26, 2020	18,915,000
Balance at Sep. 26, 2020	$ 49,268	(15,587)	775,817	809,498
Foreign currency translation adjustment				1,748
Net earnings				7,839
Balance (in shares) at Mar. 27, 2021	19,034,000
Balance at Mar. 27, 2021	$ 65,026	(13,839)	761,813	813,000
Balance (in shares) at Dec. 26, 2020	18,956,000
Balance at Dec. 26, 2020	$ 54,902	(13,308)	766,695	808,289
Issuance of common stock upon exercise of stock options (in shares)	72,000
Issuance of common stock upon exercise of stock options	$ 8,384	0	0	8,384
Foreign currency translation adjustment	0	(531)	0	(531)
Dividends declared	0	0	(10,943)	(10,943)
Share-based compensation	1,026	0	0	1,026
Net earnings	$ 0	0	6,061	6,061
Issuance of common stock for employee stock purchase plan (in shares)	6,000
Issuance of common stock for employee stock purchase plan	$ 714	0	0	714
Balance (in shares) at Mar. 27, 2021	19,034,000
Balance at Mar. 27, 2021	$ 65,026	(13,839)	761,813	$ 813,000
Balance (in shares) at Sep. 25, 2021	19,084,000			19,084,000
Balance at Sep. 25, 2021	$ 73,597	(13,383)	785,440	$ 845,654
Issuance of common stock upon exercise of stock options (in shares)	5,000
Issuance of common stock upon exercise of stock options	$ 706	0	0	706
Foreign currency translation adjustment	0	(444)	0	(444)
Dividends declared	0	0	(12,092)	(12,092)
Share-based compensation	1,083	0	0	1,083
Net earnings	$ 0	0	11,091	11,091
Balance (in shares) at Dec. 25, 2021	19,089,000
Balance at Dec. 25, 2021	$ 75,386	(13,827)	784,439	$ 845,998
Balance (in shares) at Sep. 25, 2021	19,084,000			19,084,000
Balance at Sep. 25, 2021	$ 73,597	(13,383)	785,440	$ 845,654
Foreign currency translation adjustment				102
Net earnings				$ 14,362
Balance (in shares) at Mar. 26, 2022	19,173,000			19,173,000
Balance at Mar. 26, 2022	$ 87,688	(13,281)	775,574	$ 849,981
Balance (in shares) at Dec. 25, 2021	19,089,000
Balance at Dec. 25, 2021	$ 75,386	(13,827)	784,439	845,998
Issuance of common stock upon exercise of stock options (in shares)	76,000
Issuance of common stock upon exercise of stock options	$ 10,012	0	0	10,012
Foreign currency translation adjustment	0	546	0	546
Dividends declared	0	0	(12,136)	(12,136)
Share-based compensation	1,267	0	0	1,267
Net earnings	$ 0	0	3,271	3,271
Issuance of common stock for employee stock purchase plan (in shares)	8,000
Issuance of common stock for employee stock purchase plan	$ 1,023	0	0	$ 1,023
Balance (in shares) at Mar. 26, 2022	19,173,000			19,173,000
Balance at Mar. 26, 2022	$ 87,688	$ (13,281)	$ 775,574	$ 849,981