Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Total		Common Stock [Member]	Additional paid-in capital [Member]	Accumulated other comprehensive income (loss) [Member]	Retained earnings [Member]	Treasury Stock [Member]
Balance at Jan. 01, 2021	$ 361,498		$ 66	$ 265,328	$ (1,932)	$ 421,809	$ (323,773)
Balances (in shares) at Jan. 01, 2021			65,707,000				13,903,000
Employee stock purchase plan	1,977			1,777			$ 200
Employee stock purchase plan (in shares)							(20,000)
Exercise of stock options	1,134			657			$ 477
Exercise of stock options (in shares)							(48,000)
Amortization of unrecognized stock-based compensation	9,296			9,296
Purchase of treasury shares	(7,000)						$ (7,000)
Purchase of treasury shares (in shares)							78,000
Foreign currency translation adjustments	14				14
Grant of restricted stock units to settle accrued bonus	7,637			7,637
Settlement of restricted stock units	(15,666)			(3,276)		(1,679)	$ (10,711)
Settlement of restricted stock units (in shares)							(322,000)
Unrealized loss on investments	(6)				(65)	59
Dividends and dividend equivalent rights	(43,021)			0		(43,021)
Net Income (Loss)	101,202					101,202
Balance at Dec. 31, 2021	417,065		$ 66	281,419	(1,983)	478,370	$ (340,807)
Balances (in shares) at Dec. 31, 2021			65,707,000				13,591,000
Employee stock purchase plan	2,020			1,805			$ 215
Employee stock purchase plan (in shares)							(22,000)
Amortization of unrecognized stock-based compensation	9,999			9,999
Purchase of treasury shares	(155,856)						$ (155,856)
Purchase of treasury shares (in shares)							1,756,000
Foreign currency translation adjustments	(1,604)				(1,604)
Grant of restricted stock units to settle accrued bonus	10,200			10,200
Settlement of restricted stock units	(12,904)			(2,421)		(1,392)	$ (9,091)
Settlement of restricted stock units (in shares)							(261,000)
Dividends and dividend equivalent rights	(50,498)					(50,498)
Net Income (Loss)	102,330					102,330
Balance at Dec. 30, 2022	320,752		$ 66	301,002	(3,587)	528,810	$ (505,539)
Balances (in shares) at Dec. 30, 2022			65,707,000				15,064,000
Employee stock purchase plan	2,084			1,840			$ 244
Employee stock purchase plan (in shares)							(24,000)
Exercise of stock options	$ 100			22			$ 78
Exercise of stock options (in shares)	(7,992)	[1]					(8,000)
Amortization of unrecognized stock-based compensation	$ 9,912			9,912
Purchase of treasury shares	(24,208)						$ (24,208)
Purchase of treasury shares (in shares)							288,000
Foreign currency translation adjustments	610				610
Grant of restricted stock units to settle accrued bonus	10,496			10,496
Settlement of restricted stock units	(9,942)			(1,824)		(1,009)	$ (7,109)
Settlement of restricted stock units (in shares)							(186,000)
Dividends and dividend equivalent rights	(54,058)					(54,058)
Net Income (Loss)	100,339					100,339
Balance at Dec. 29, 2023	$ 356,085		$ 66	$ 321,448	$ (2,977)	$ 574,082	$ (536,534)
Balances (in shares) at Dec. 29, 2023			65,707,000				15,134,000

[1] Does not include restricted stock or employee stock purchase plans.