Note 11 - Equity Offerings (Details Textual) - The 2022 ATM Offering [Member] - USD ($) shares in Thousands, $ in Billions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Mar. 18, 2022
Stock Offering Agreement, Maximum Share Value			$ 0.1
Stock Issued During Period, Shares, New Issues (in shares)	0	0