v3.26.1
Note 2 - Business Combinations - Schedule of Business Combination Information (Details) - USD ($)
$ / shares in Units, $ in Thousands
Jan. 01, 2026
Jun. 30, 2026
Dec. 31, 2025
Dec. 31, 2024
Goodwill   $ 58,267 $ 40,088 $ 40,088
W F B [Member]        
Business Combination, Consideration Transferred, Equity Interest, Share Issued, Number of Shares (in shares) 3,955,272      
Price per share, based on Investar common stock price as of December 31, 2025 (in dollars per share) $ 26.72      
Fair value of Investar common stock issued $ 105,685      
Payments to Acquire Businesses, Gross 7,202      
Business Combination, Consideration Transferred 112,887      
Cash and cash equivalents 82,910      
Investment securities 51,455      
Net loans 950,235      
Nonmarketable equity securities 3,621      
Bank premises and equipment 19,834      
BOLI 13,751      
Other assets 10,034      
Total assets acquired 1,145,410      
Deposits 1,023,365      
Repurchase agreements 1,193      
Notes payable 9,163      
Other borrowings 15,051      
Other liabilities 1,930      
Total liabilities assumed 1,050,702      
Fair value of net assets acquired 94,708      
Goodwill 18,179      
W F B [Member] | Core Deposits [Member]        
Business Combination, Recognized Asset Acquired, Identifiable Intangible Asset, Finite-Lived $ 13,570 $ 13,600