Condensed Financial Information (Parent Company Only) (Condensed Statements of Income) (Details) - USD ($) $ in Thousands	3 Months Ended												12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income
Total interest and dividend income	$ 20,892	$ 21,617	$ 21,518	$ 21,302	$ 21,489	$ 20,836	$ 20,621	$ 16,748	$ 15,081	$ 15,026	$ 14,652	$ 14,109	$ 85,329	$ 79,694	$ 58,868
Expenses	4,926	5,372	5,474	5,260	4,995	4,419	4,013	3,164	2,888	2,762	2,565	2,396	21,032	16,591	10,611
Income tax benefit													2,359	2,960	6,793
Net Income Available to Common Shareholders	$ 6,628	$ 6,134	$ 5,751	$ 5,238	$ 5,290	$ 5,402	$ 4,165	$ 4,007	$ 1,460	$ 3,751	$ 3,898	$ 3,206	23,751	18,864	12,315
MutualFirst Financial, Inc.
Income
Dividends from subsidiaries													11,000	6,695	15,100
Other Income													15	9
Total interest and dividend income													11,015	6,704	15,100
Expenses													2,710	1,922	1,041
Income before income tax and equity in undistributed income of subsidiaries													8,305	4,782	14,059
Income tax benefit													(498)	(412)	(495)
Income before equity in undistributed income (distributions in excess of income) of subsidiaries													8,803	5,194	14,554
Equity in undistributed income (distributions in excess of income) of subsidiaries													14,948	13,670	(2,239)
Net Income Available to Common Shareholders													$ 23,751	$ 18,864	$ 12,315