Condensed Consolidated Statements of Stockholders' Equity (Unaudited) - USD ($) $ in Thousands	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	AOCI Attributable to Parent [Member]	Treasury Stock, Common [Member]	Total
Balance at Dec. 25, 2021	$ 48,756	$ 674,777	$ 193,555	$ (27,262)	$ (7,324)	$ 882,502
Net income (loss)	0	0	50,337	0	0	50,337
Changes in cumulative translation adjustment	0	0	0	(21,440)	0	(21,440)
Adjustments related to postretirement benefits	0	0	0	(173)	0	(173)
Changes in unrealized gains and losses on investments, net of tax	0	0	0	(510)	0	(510)
Shares issued under ESPP	77	1,669	0	0	0	1,746
Shares issued for restricted stock units vested	466	(466)	0	0	0	0
Repurchase and retirement of stock	(160)	(4,945)	0	0	0	(5,105)
Common stock repurchases	0	0	0	0	(20,378)	(20,378)
Share-based compensation expense	0	7,355	0	0	0	7,355
Exercise of stock options	13	105	0	0	0	118
Balance at Jun. 25, 2022	49,152	678,495	243,892	(49,385)	(27,702)	894,452
Balance at Mar. 26, 2022	49,025	673,034	215,124	(36,574)	(13,712)	886,897
Net income (loss)	0	0	28,768	0	0	28,768
Changes in cumulative translation adjustment	0	0	0	(12,537)	0	(12,537)
Adjustments related to postretirement benefits	0	0	0	(112)	0	(112)
Changes in unrealized gains and losses on investments, net of tax	0	0	0	(162)	0	(162)
Shares issued under ESPP	77	1,669	0	0	0	1,746
Shares issued for restricted stock units vested	40	(40)	0	0	0	0
Repurchase and retirement of stock	(3)	(206)	0	0	0	(209)
Common stock repurchases	0	0	0	0	(13,990)	(13,990)
Share-based compensation expense	0	3,933	0	0	0	3,933
Exercise of stock options	13	105	0	0	0	118
Balance at Jun. 25, 2022	49,152	678,495	243,892	(49,385)	(27,702)	894,452
Balance at Dec. 31, 2022	49,276	687,218	290,402	(40,012)	(58,043)	928,841	[1]
Net income (loss)	0	0	26,269	0	0	26,269
Changes in cumulative translation adjustment	0	0	0	3,059	0	3,059
Adjustments related to postretirement benefits	0	0	0	186	0	186
Changes in unrealized gains and losses on investments, net of tax	0	0	0	208	0	208
Shares issued under ESPP	67	1,837	0	0	0	1,904
Shares issued for restricted stock units vested	7	(19,225)	0	0	19,218	0
Repurchase and retirement of stock	0	(1,867)	0	0	(7,373)	(9,240)
Common stock repurchases	0	0	0	0	(6,180)	(6,180)
Share-based compensation expense	0	8,346	0	0	0	8,346
Balance at Jul. 01, 2023	49,350	676,309	316,671	(36,559)	(52,378)	953,393
Balance at Apr. 01, 2023	49,283	671,204	306,087	(37,009)	(50,786)	938,779
Net income (loss)	0	0	10,584	0	0	10,584
Changes in cumulative translation adjustment	0	0	0	358	0	358
Adjustments related to postretirement benefits	0	0	0	157	0	157
Changes in unrealized gains and losses on investments, net of tax	0	0	0	(65)	0	(65)
Shares issued under ESPP	67	1,837	0	0	0	1,904
Shares issued for restricted stock units vested	0	(1,158)	0	0	1,158	0
Repurchase and retirement of stock	0	(6)	0	0	(51)	(57)
Common stock repurchases	0	0	0	0	(2,699)	(2,699)
Share-based compensation expense	0	4,432	0	0	0	4,432
Balance at Jul. 01, 2023	$ 49,350	$ 676,309	$ 316,671	$ (36,559)	$ (52,378)	$ 953,393

[1] Derived from December 31, 2022 audited financial statements