Condensed Financial Information (Parent Company Only) (Condensed Statements of Cash Flows) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Operating Activities
Net income	$ 23,751	$ 18,864	$ 12,315
Item not requiring cash
Deferred income tax	(277)	3,465	3,562
Other	231	164	259
Net cash provided by operating activities	20,748	27,128	20,042
Investing Activities
Net cash and cash equivalents paid in acquisition		(7,673)
Net cash provided by (used in) investing activities	1,359	(76,273)	(41,079)
Financing Activities
Cash dividends	(6,860)	(6,354)	(4,862)
Proceeds from stock options exercised	1,046	253	1,156
Net cash provided by (used in) financing activities	(23,198)	55,218	21,518
Net Change in Cash and Cash Equivalents	(1,091)	6,073	481
Cash and Cash Equivalents, Beginning of Period	33,414
Cash and Cash Equivalents, End of Period	32,323	33,414
MutualFirst Financial, Inc.
Operating Activities
Net income	23,751	18,864	12,315
Item not requiring cash
Deferred income tax	314	20	(14)
(Equity in undistributed income) distributions in excess of income of subsidiary	(14,948)	(13,670)	2,239
Other	865	(660)	74
Net cash provided by operating activities	9,982	4,554	14,614
Investing Activities
Net cash and cash equivalents paid in acquisition		(16,463)
Net cash provided by (used in) investing activities		(16,463)
Financing Activities
Repayments of other borrowings	(515)	(335)
Proceeds from other borrowings		10,000
Stock repurchased	(4,262)
Cash dividends	(6,860)	(6,354)	(4,862)
Proceeds from stock options exercised	1,046	253	1,156
Net cash provided by (used in) financing activities	(10,591)	3,564	(3,706)
Net Change in Cash and Cash Equivalents	(609)	(8,345)	10,908
Cash and Cash Equivalents, Beginning of Period	3,685	12,030	1,122
Cash and Cash Equivalents, End of Period	$ 3,076	$ 3,685	$ 12,030