Note 11 - Stockholders' Equity - Summary of ATM Program Sales (Details) - USD ($)		3 Months Ended
	Aug. 20, 2021	Mar. 31, 2022	Mar. 31, 2021
Net Proceeds		$ 113,535,000	$ 0
At-the-market Offering [Member]
Gross Proceeds		$ 11,264,237
Shares of Common Stock Issued (in shares)		532,694
Gross Average Sale Price per Share of Common Stock (in dollars per share)		$ 21.15
Sales Commissions		$ 168,963
Offering Costs		793,779
Net Proceeds		$ 10,301,495
Average Price Per Share, net (in dollars per share)		$ 19.34
The 2022 At The Market Program (ATM) [Member]
Shares of Common Stock Issued (in shares)		91,428
Gross Average Sale Price per Share of Common Stock (in dollars per share)		$ 91,428
Sales Commissions		$ 30,787
Offering Costs		208,873
Net Proceeds		$ 1,812,114
Average Price Per Share, net (in dollars per share)		$ 19.82
Gross Proceeds		$ 2,051,774
Gross Average Sale Price per Share of Common Stock (in dollars per share)		$ 22.44
Underwriting Agreement, Including Option Shares [Member]
Gross Proceeds	$ 43,253,700
Shares of Common Stock Issued (in shares)	2,059,700
Gross Average Sale Price per Share of Common Stock (in dollars per share)	$ 21.00
Offering Costs	$ 813,748
Net Proceeds	$ 40,493,535
Average Price Per Share, net (in dollars per share)	$ 19.66
Underwriting Discounts	$ 1,946,417