Condensed Balance Sheets (Current Period Unaudited) (Parentheticals) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Pledged assets	$ 3,999,906	$ 3,540,002
Pledged assets	$ 36,806	$ 36,382
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, authorized (in shares)	20,000,000	20,000,000
Preferred stock, issued (in shares)	0	0
Preferred stock, outstanding (in shares)	0	0
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, authorized (in shares)	100,000,000	100,000,000
Common stock, issued (in shares)	39,085,756	36,764,983
Common stock, outstanding (in shares)	39,085,756	36,764,983
Asset Pledged as Collateral [Member]
Pledged assets	$ 3,946,156	$ 3,512,640
Pledged assets	$ 36,306	$ 36,382