Condensed Balance Sheets (Current Period Unaudited) (Parentheticals) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Pledged assets	$ 3,881,078	$ 3,894,012
Pledged assets	$ 99,496	$ 148,820
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)	52,826,169	51,636,074
Common stock, outstanding (in shares)	52,826,169	51,636,074
Asset Pledged as Collateral [Member]
Pledged assets	$ 3,875,705	$ 3,885,554
Pledged assets	$ 79,590	$ 79,680