Note 5 - Income (Loss) Per Common Share (Details Textual)	3 Months Ended
	Mar. 31, 2021 shares
Incremental Common Shares Attributable to Share-based Payment Arrangements, Total (in shares)	2,863,038
Incremental Common Shares Attributable to Dilutive Effect of Call Options and Warrants (in shares)	1,536,615
Incremental Common Shares Attributable to Dilutive Effect of Deferred Shares (in shares)	2,026,440