Note 25 - Supplemental Disclosure for Earnings Per Share - Supplemental Disclosure for Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended												12 Months Ended
	Dec. 31, 2021	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Net income attributable to First Capital, Inc.	$ 2,819	$ 2,936	$ 2,730	$ 2,939	$ 2,853	$ 2,746	$ 2,438	$ 2,094	$ 2,403	$ 2,915	$ 2,860	$ 2,147	$ 11,424	$ 10,131	$ 10,325
Weighted average common shares outstanding (in shares)													3,346,038	3,339,812	3,332,869
Net income attributable to First Capital, Inc. per common share, basic (in dollars per share)	$ 0.83	$ 0.88	$ 0.82	$ 0.88	$ 0.85	$ 0.82	$ 0.73	$ 0.63	$ 0.72	$ 0.87	$ 0.86	$ 0.64	$ 3.41	$ 3.03	$ 3.10
Net income attributable to First Capital, Inc.													$ 11,424	$ 10,131	$ 10,325
Weighted average common shares outstanding (in shares)													3,346,038	3,339,812	3,332,869
Add: Dilutive effect of restricted stock (in shares)													457	9,465	11,203
Weighted average common shares outstanding, as adjusted (in shares)													3,346,495	3,349,277	3,344,072
Net income attributable to First Capital, Inc. per common share, diluted (in dollars per share)	$ 0.83	$ 0.88	$ 0.82	$ 0.88	$ 0.84	$ 0.82	$ 0.73	$ 0.63	$ 0.72	$ 0.87	$ 0.86	$ 0.64	$ 3.41	$ 3.02	$ 3.09