Note 9 - Financial Instruments With Off-balance-sheet Risk - Unfunded Commitments (Details) - USD ($) $ in Thousands	Dec. 31, 2025	Dec. 31, 2024
Unfunded commitments, principal balance	$ 104,000	$ 181,000
Fair value of unfunded commitment liability	794	1,637
Britecore Holdings, Inc. [Member]
Unfunded commitments, principal balance	5,000	2,500
Fair value of unfunded commitment liability	50	36
Candesant Biomedical, Inc. [Member]
Unfunded commitments, principal balance	0	10,000
Fair value of unfunded commitment liability	0	151
Ceribell, Inc. [Member]
Unfunded commitments, principal balance	21,000	21,000
Fair value of unfunded commitment liability	120	120
Crafty Holdings, Inc.[Member]
Unfunded commitments, principal balance	3,000	5,000
Fair value of unfunded commitment liability	39	65
Fictiv, Inc. [Member]
Unfunded commitments, principal balance	0	30,000
Fair value of unfunded commitment liability	0	236
GT Medical Technologies, Inc. [Member]
Unfunded commitments, principal balance	20,000	20,000
Fair value of unfunded commitment liability	100	100
Hometeam Technologies, Inc [Member]
Unfunded commitments, principal balance	0	10,000
Fair value of unfunded commitment liability	0	100
InfoBionic, Inc [Member]
Unfunded commitments, principal balance	5,000	0
Fair value of unfunded commitment liability	50	0
Long Grove Pharmaceuticals, LLC [Member]
Unfunded commitments, principal balance	10,000	0
Fair value of unfunded commitment liability	75	0
MasteryPrep, LLC [Member]
Unfunded commitments, principal balance	5,000	0
Fair value of unfunded commitment liability	50	0
MicroTransponder, Inc. [Member]
Unfunded commitments, principal balance	0	15,000
Fair value of unfunded commitment liability	0	0
MML US, Inc [Member]
Unfunded commitments, principal balance	20,000	0
Fair value of unfunded commitment liability	100	0
OneNetworks, Inc. dba Finexio [Member]
Unfunded commitments, principal balance	0	5,000
Fair value of unfunded commitment liability	0	26
Onkos Surgical, Inc. [Member]
Unfunded commitments, principal balance	0	5,000
Fair value of unfunded commitment liability	0	27
Parse Biosciences, Inc. [Member]
Unfunded commitments, principal balance	0	15,000
Fair value of unfunded commitment liability	0	252
Pivot Bio, Inc. [Member]
Unfunded commitments, principal balance	0	20,000
Fair value of unfunded commitment liability	0	209
Samba TV, Inc. [Member]
Unfunded commitments, principal balance	5,000	0
Fair value of unfunded commitment liability	75	0
SafelyYou, Inc [Member]
Unfunded commitments, principal balance	0	5,000
Fair value of unfunded commitment liability	0	73
Sparkcharge, Inc. [Member]
Unfunded commitments, principal balance	5,000	0
Fair value of unfunded commitment liability	73	0
Standvast Holdings, LLC [Member]
Unfunded commitments, principal balance	0	2,500
Fair value of unfunded commitment liability	0	88
Supply Network Visibility Holdings, LLC [Member]
Unfunded commitments, principal balance	5,000	10,000
Fair value of unfunded commitment liability	62	79
Ursa Space Systems Inc. [Member]
Unfunded commitments, principal balance	0	5,000
Fair value of unfunded commitment liability	$ 0	$ 75