Note 2 - Summary of Significant Accounting Policies - Weighted Average Common Shares (Details) - shares	3 Months Ended																12 Months Ended
	Dec. 31, 2021	[1]	Sep. 30, 2021	[2]	Jun. 30, 2021	[3]	Mar. 31, 2021	[4]	Dec. 31, 2020	[5]	Sep. 30, 2020	[6]	Jun. 30, 2020	[7]	Mar. 31, 2020	[8]	Dec. 31, 2021	Dec. 31, 2020
Weighted average common shares outstanding–basic (in shares)	10,580,431		10,496,188		10,442,916		10,329,449		10,282,903		10,269,995		10,252,490		10,220,853		10,462,246	10,256,560
Unvested shares of restricted stock and employee stock options (in shares)																	267,616	0
Weighted average common shares and common share equivalents outstanding – diluted (in shares)	10,836,396		10,792,290		10,764,936		10,525,826		10,282,903		10,287,562		10,258,917		10,220,853		10,729,862	10,256,560
Average number of potentially dilutive securities excluded from calculation (in shares)																	231,938	717,015

[1] The quarter ended December 31, 2021 includes a recovery of $17 of restructuring and other charges which are discussed in Note 5.

[2] The quarter ended September 30, 2021 includes $51 of restructuring and other charges which are discussed in Note 5.

[3] The quarter ended June 30, 2021 includes $197 of restructuring and other charges which are discussed in Note 5.

[4] The quarter ended March 31, 2021 includes $55 of restructuring and other charges which are discussed in Note 5.

[5] The quarter ended December 31, 2020 includes $1,078 of restructuring and other charges which are discussed in Note 5.

[6] The quarter ended September 30, 2020 includes $161 of restructuring and other charges which are discussed in Note 5.

[7] The quarter ended June 30, 2020 includes $38 of restructuring and other charges which are discussed in Note 5.

[8] The quarter ended March 31, 2020 includes $8 of restructuring and other charges which are discussed in Note 5.