Condensed Financial Information (Parent Company Only) (Condensed Statements of Cash Flows) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Operating Activities
Net income	$ 18,864	$ 12,315	$ 13,241
Item not requiring cash
Deferred income tax	3,465	3,562	1,537
Other	164	259	143
Net cash provided by operating activities	27,128	20,042	18,551
Investing Activities
Net cash and cash equivalents paid in acquisition	(7,673)
Net cash used in investing activities	(76,273)	(41,079)	(76,606)
Financing Activities
Cash dividends	(6,354)	(4,862)	(4,284)
Proceeds from stock options exercised	253	1,156	976
Net cash provided by financing activities	55,218	21,518	64,000
Net Change in Cash and Cash Equivalents	6,073	481	5,945
Cash and Cash Equivalents, Beginning of Period	27,341	26,860	20,915
Cash and Cash Equivalents, End of Period	33,414	27,341	26,860
MutualFirst Financial, Inc.
Operating Activities
Net income	18,864	12,315	13,241
Item not requiring cash
Deferred income tax	20	(14)	200
(Equity in undistributed income) distributions in excess of income of subsidiary	(13,670)	2,239	(1,818)
Other	(660)	74	(183)
Net cash provided by operating activities	4,554	14,614	11,440
Investing Activities
Investment in subsidiary			(100)
Net cash and cash equivalents paid in acquisition	(16,463)
Net cash used in investing activities	(16,463)		(100)
Financing Activities
Repayments of other borrowings	(335)		(5,312)
Proceeds from other borrowings	10,000
Stock repurchased			(4,354)
Cash dividends	(6,354)	(4,862)	(4,284)
Proceeds from stock options exercised	253	1,156	976
Net cash provided by financing activities	3,564	(3,706)	(12,974)
Net Change in Cash and Cash Equivalents	(8,345)	10,908	(1,634)
Cash and Cash Equivalents, Beginning of Period	12,030	1,122	2,756
Cash and Cash Equivalents, End of Period	$ 3,685	$ 12,030	$ 1,122