Condensed Consolidated Statements of Stockholders' Equity (Unaudited) - USD ($) $ in Thousands	Common Stock [Member] Common Class A [Member]	Common Stock [Member] Common Class B [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	AOCI Attributable to Parent [Member]	Treasury Stock [Member]	Total
Balance (in shares) at Jul. 01, 2018	52,071,293	33,822,823				21,258,790
Balance at Jul. 01, 2018	$ 520	$ 338	$ 341,783	$ 73,429	$ (200)	$ (100,966)	$ 314,904
Net income (loss)				43,071			43,071
Translation adjustment					(58)		(58)
Stock-based compensation (in shares)	411,600
Stock-based compensation	$ 4		4,527				4,531
Acquisition of Class A treasury stock (in shares)						1,230,303
Acquisition of Class A treasury stock						$ (14,765)	(14,765)
Net income (loss)				43,071			43,071
Exercise of stock options (in shares)	448,234
Exercise of stock options	$ 4		925				929
Other				330			330
Balance (in shares) at Mar. 31, 2019	52,931,127	33,822,823				22,489,093
Balance at Mar. 31, 2019	$ 528	$ 338	347,235	116,830	(258)	$ (115,731)	348,942
Balance (in shares) at Dec. 30, 2018	52,749,203	33,822,823				22,383,738
Balance at Dec. 30, 2018	$ 527	$ 338	344,769	125,071	(261)	$ (114,371)	356,073
Net income (loss)				(8,241)			(8,241)
Translation adjustment					3		3
Stock-based compensation (in shares)	1,924
Stock-based compensation			1,903				1,903
Acquisition of Class A treasury stock (in shares)						105,355
Acquisition of Class A treasury stock						$ (1,360)	(1,360)
Net income (loss)				(8,241)			(8,241)
Exercise of stock options (in shares)	180,000
Exercise of stock options	$ 1		563				564
Balance (in shares) at Mar. 31, 2019	52,931,127	33,822,823				22,489,093
Balance at Mar. 31, 2019	$ 528	$ 338	347,235	116,830	(258)	$ (115,731)	348,942
Balance (in shares) at Jun. 30, 2019	53,084,127	33,822,823				22,489,093
Balance at Jun. 30, 2019	$ 530	$ 338	349,319	108,525	(269)	$ (115,732)	342,711
Net income (loss)				49,224			49,224
Translation adjustment					17		17
Stock-based compensation (in shares)	468,683
Stock-based compensation	$ 5		6,436				6,441
Acquisition of Class A treasury stock (in shares)						753,804
Acquisition of Class A treasury stock						$ (10,667)	(10,667)
Net income (loss)				49,224			$ 49,224
Exercise of stock options (in shares)	150,000						150,000
Exercise of stock options	$ 2		283				$ 285
Balance (in shares) at Mar. 29, 2020	53,702,810	33,822,823				23,242,897
Balance at Mar. 29, 2020	$ 537	$ 338	356,038	157,749	(252)	$ (126,399)	388,011
Balance (in shares) at Dec. 29, 2019	53,678,919	33,822,823				22,859,956
Balance at Dec. 29, 2019	$ 536	$ 338	353,643	167,406	(253)	$ (120,762)	400,908
Net income (loss)				(9,657)			(9,657)
Translation adjustment					1		1
Stock-based compensation (in shares)	23,891
Stock-based compensation	$ 1		2,395				2,396
Acquisition of Class A treasury stock (in shares)						382,941
Acquisition of Class A treasury stock						$ (5,637)	(5,637)
Net income (loss)				(9,657)			(9,657)
Balance (in shares) at Mar. 29, 2020	53,702,810	33,822,823				23,242,897
Balance at Mar. 29, 2020	$ 537	$ 338	$ 356,038	$ 157,749	$ (252)	$ (126,399)	$ 388,011