Note 26 - Selected Quarterly Financial Information (Unaudited) - Selected Quarterly Financial Information (Unaudited) (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
Interest income	$ 7,290	$ 7,745	$ 7,133	$ 7,292	$ 7,359	$ 7,240	$ 7,374	$ 7,674	$ 7,957	$ 8,220	$ 8,219	$ 7,658	$ 29,460	$ 29,647	$ 32,054
Interest expense	273	278	289	288	318	371	404	468	510	503	491	456	1,128	1,561	1,960
Net interest income	7,017	7,467	6,844	7,004	7,041	6,869	6,970	7,206	7,447	7,717	7,728	7,202	28,332	28,086	30,094
Provision (credit) for loan losses	(400)	0	0	75	225	400	825	351	450	225	300	450	(325)	1,801	1,425
Net interest income after provision for loan losses	7,417	7,467	6,844	6,929	6,816	6,469	6,145	6,855	6,997	7,492	7,428	6,752	28,657	26,285	28,669
Noninterest income	2,291	2,270	2,552	2,438	2,207	2,616	2,320	1,456	1,820	1,833	1,768	1,505	9,551	8,599	6,926
Noninterest expenses	6,357	6,202	6,165	5,807	5,682	5,923	5,618	5,825	5,971	5,870	5,764	5,665	24,531	23,048	23,270
Income before income taxes	3,351	3,535	3,231	3,560	3,341	3,162	2,847	2,486	2,846	3,455	3,432	2,592	13,677	11,836	12,325
Income tax expense	529	596	497	618	485	413	405	389	440	537	568	442	2,240	1,692	1,987
Net Income	2,822	2,939	2,734	2,942	2,856	2,749	2,442	2,097	2,406	2,918	2,864	2,150	11,437	10,144	10,338
Less net income attributable to the noncontrolling interest in subsidiary	3	3	4	3	3	3	4	3	3	3	4	3	13	13	13
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
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
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