Note 6 - Equity and Stock-based Compensation - Stock Option Activity (Details) - The 2016 Omnibus Plan [Member] - $ / shares	3 Months Ended	12 Months Ended
	Mar. 31, 2023	Dec. 30, 2022
Shares outstanding (in shares)	3,376,667
Shares outstanding, weighted-average exercise price (in dollars per share)	$ 0.64
Shares outstanding, weighted-average remaining contractual term (Year)	6 years 5 months 12 days	6 years 8 months 12 days
Shares granted (in shares)	0
Shares granted, weighted-average exercise price (in dollars per share)	$ 0
Shares exercised (in shares)	0
Shares exercised, weighted-average exercise price (in dollars per share)	$ 0
Shares forfeited or expired (in shares)	0
Shares forfeited or expired, weighted-average exercise price (in dollars per share)	$ 0
Shares outstanding (in shares)	3,376,667
Shares outstanding, weighted-average exercise price (in dollars per share)	$ 0.64
Shares exercisable (in shares)	2,252,778
Shares exercisable, weighted-average exercise price (in dollars per share)	$ 0.57
Shares exercisable, weighted-average remaining contractual term (Year)	5 years 1 month 28 days