Note 5 - Stockholders' Equity and Stock-based Compensation - Unvested Restricted Stock and Deferred Stock (Details) - $ / shares		12 Months Ended
Jun. 25, 2020	Dec. 31, 2021	Dec. 31, 2020
Non-Employee Board Member Stock Option and Restricted Stock [Member]
Non-Vested Balance (in shares)		20,073
Non-Vested Balance, weighted average fair value per share (in dollars per share)		$ 11.17
Granted (in shares)		10,710
Granted, weighted average fair value per share (in dollars per share)		$ 14.00
Vested (in shares)		(20,073)
Vested, weighted average fair value per share (in dollars per share)		$ 11.17
Forfeited (in shares)		0
Forfeited, weighted average fair value per share (in dollars per share)		$ 0
Non-Vested Balance (in shares)		10,710	20,073
Non-Vested Balance, weighted average fair value per share (in dollars per share)		$ 14.00	$ 11.17
Employee Deferred Stock Award [Member]
Non-Vested Balance (in shares)		18,800
Non-Vested Balance, weighted average fair value per share (in dollars per share)		$ 11.07
Granted (in shares)	47,000	27,900
Granted, weighted average fair value per share (in dollars per share)		$ 13.33	$ 11.07
Vested (in shares)		0
Vested, weighted average fair value per share (in dollars per share)		$ 0
Forfeited (in shares)		(3,300)
Forfeited, weighted average fair value per share (in dollars per share)		$ 11.69
Non-Vested Balance (in shares)		43,400	18,800
Non-Vested Balance, weighted average fair value per share (in dollars per share)		$ 12.48	$ 11.07

The number of equity-based payment instruments, excluding stock (or unit) options, that were forfeited during the reporting period.

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