Condensed Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands		Total	Common Stock		Treasury Stock	Additional Paid-in Capital	Accumulated Deficit
Beginning balance (in shares) at Dec. 31, 2019			46,557,934	[1]	2,423,871
Beginning balance at Dec. 31, 2019		$ 50,571	$ 466	[1]	$ (35,000)	$ 200,585	$ (115,480)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock plan transactions and other (in shares)	[1]		220,748
Stock plan transactions and other		(272)	$ 2	[1]		(274)
Stock-based compensation expense		1,290				1,290
Net income (loss)		(19,313)					(19,313)
Ending balance (in shares) at Jun. 30, 2020			46,778,682	[1]	2,423,871
Ending balance at Jun. 30, 2020		32,276	$ 468	[1]	$ (35,000)	201,601	(134,793)
Beginning balance (in shares) at Mar. 31, 2020			46,583,879	[1]	2,423,871
Beginning balance at Mar. 31, 2020		44,906	$ 466	[1]	$ (35,000)	200,755	(121,315)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock plan transactions and other (in shares)	[1]		194,803
Stock plan transactions and other		(271)	$ 2	[1]		(273)
Stock-based compensation expense		1,119				1,119
Net income (loss)		(13,478)					(13,478)
Ending balance (in shares) at Jun. 30, 2020			46,778,682	[1]	2,423,871
Ending balance at Jun. 30, 2020		32,276	$ 468	[1]	$ (35,000)	201,601	(134,793)
Beginning balance (in shares) at Dec. 29, 2020			46,807,587	[1]	2,423,871
Beginning balance at Dec. 29, 2020		29,699	$ 468	[1]	$ (35,000)	202,970	(138,739)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
L Catterton warrants exercised (in shares)	[1]		975,458
L Catterton warrants exercised		0	$ 10	[1]		(10)
Stock plan transactions and other (in shares)	[1]		228,716
Stock plan transactions and other		(279)	$ 2	[1]		(281)
Stock-based compensation expense		2,317				2,317
Net income (loss)		3,706					3,706
Ending balance (in shares) at Jun. 29, 2021			48,011,761	[1]	2,423,871
Ending balance at Jun. 29, 2021		35,443	$ 480	[1]	$ (35,000)	204,996	(135,033)
Beginning balance (in shares) at Mar. 30, 2021			47,890,488	[1]	2,423,871
Beginning balance at Mar. 30, 2021		28,125	$ 479	[1]	$ (35,000)	203,362	(140,716)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock plan transactions and other (in shares)	[1]		121,273
Stock plan transactions and other		56	$ 1	[1]		55
Stock-based compensation expense		1,579				1,579
Net income (loss)		5,683					5,683
Ending balance (in shares) at Jun. 29, 2021			48,011,761	[1]	2,423,871
Ending balance at Jun. 29, 2021		$ 35,443	$ 480	[1]	$ (35,000)	$ 204,996	$ (135,033)

[1] Unless otherwise noted, activity relates to Class A common stock.