Note 18 - Regulatory Matters (Tables)

12 Months Ended

Dec. 31, 2025

Notes Tables

Schedule of Compliance with Regulatory Capital Requirements under Banking Regulations [Table Text Block]

		*Actual*								Capital Adequacy^*								*Well Capitalized*
		*Amount*				*Ratio*				*Amount*				*Ratio*				*Amount*				*Ratio*
December 31, 2025
Tier 1 leverage capital
Investar Holding Corporation		$	305,810				10.73	%		$	113,987				4.00	%		NA				NA
Investar Bank			308,528				10.85				113,784				4.00				142,230				5.00

Common Equity Tier 1 risk-based capital
Investar Holding Corporation			265,957				11.18				166,592				7.00			NA				NA
Investar Bank			308,528				13.00				166,160				7.00				154,291				6.50

Tier 1 risk-based capital
Investar Holding Corporation			305,810				12.85				202,290				8.50			NA				NA
Investar Bank			308,528				13.00				201,765				8.50				189,897				8.00

Total risk-based capital
Investar Holding Corporation			348,943				14.66				249,887				10.50			NA				NA
Investar Bank			334,923				14.11				249,240				10.50				237,371				10.00

December 31, 2024
Tier 1 leverage capital
Investar Holding Corporation		$	258,178				9.27	%		$	111,403				4.00	%		NA				NA
Investar Bank			269,733				9.70				111,274				4.00				139,092				5.00

Common Equity Tier 1 risk-based capital
Investar Holding Corporation			248,678				10.84				160,614				7.00			NA				NA
Investar Bank			269,733				11.77				160,381				7.00				148,925				6.50

Tier 1 risk-based capital
Investar Holding Corporation			258,178				11.25				195,032				8.50			NA				NA
Investar Bank			269,733				11.77				194,749				8.50				183,293				8.00

Total risk-based capital
Investar Holding Corporation			301,259				13.13				240,922				10.50			NA				NA
Investar Bank			296,117				12.92				240,572				10.50				229,116				10.00