Condensed Financial Information (Parent Company Only) (Condensed Statements of Cash Flows) (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Operating Activities
Net income	$ 10,818,000	$ 9,200,000	$ 7,246,000
Item not requiring cash
ESOP shares earned	0	474,000	328,000
Deferred income tax	914,000	2,213,000	582,000
Other	702,000	558,000	524,000
Net cash provided by operating activities	12,010,000	21,619,000	20,461,000
Investing Activities
Net cash provided by (used in) investing activities	(21,760,000)	5,626,000	(28,430,000)
Financing Activities
Repayment of other borrowings	(759,000)	(759,000)	(847,000)
Cash dividends	(2,297,000)	(2,953,000)	(3,113,000)
Proceeds from stock options exercised	1,347,000	570,000	551,000
Net cash provided by (used in) financing activities	14,040,000	(34,738,000)	(14,476,000)
Net Change in Cash and Cash Equivalents	4,290,000	(7,493,000)	(22,445,000)
Cash and Cash Equivalents, Beginning of Period	25,285,000	32,778,000	55,223,000
Cash and Cash Equivalents, End of Period	29,575,000	25,285,000	32,778,000
MutualFirst Financial, Inc. [Member]
Operating Activities
Net income	10,818,000	9,200,000	7,246,000
Item not requiring cash
ESOP shares earned		474,000	329,000
Deferred income tax	159,000	71,000	(263,000)
(Equity in undistributed income) distributions in excess of income of subsidiary	(7,974,000)	20,802,000	(3,086,000)
Other	19,000	(365,000)	462,000
Net cash provided by operating activities	3,022,000	30,182,000	4,688,000
Financing Activities
Repayment of other borrowings	(759,000)	(759,000)	(847,000)
Stock repurchased		(28,924,000)
Cash dividends	(2,297,000)	(2,953,000)	(3,113,000)
Proceeds from stock options exercised	1,347,000	570,000	551,000
Net cash provided by (used in) financing activities	(1,709,000)	(32,066,000)	(3,409,000)
Net Change in Cash and Cash Equivalents	1,313,000	(1,884,000)	1,279,000
Cash and Cash Equivalents, Beginning of Period	1,070,000	2,954,000	1,675,000
Cash and Cash Equivalents, End of Period	$ 2,383,000	$ 1,070,000	$ 2,954,000