Condensed Financial Information (Parent Company Only) (Condensed Statements of Cash Flows) (Details) - USD ($) $ in Thousands	3 Months Ended												12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Operating Activities
Net income	$ 3,338	$ 3,225	$ 3,218	$ 2,481	$ 3,661	$ 2,751	$ 2,614	$ 2,020	$ 2,686	$ 2,518	$ 2,157	$ 2,022	$ 12,262	$ 11,046	$ 9,383
Item not requiring cash
Deferred income tax													1,926	1,087	2,387
Other													143	474	375
Net cash provided by operating activities													16,137	12,010	21,619
Investing Activities
Net cash provided by (used in) investing activities													(67,736)	(21,760)	5,626
Financing Activities
Repayments of other borrowings													(759)	(759)	(759)
Cash dividends													(3,550)	(2,297)	(2,953)
Proceeds from stock options exercised													2,011	1,347	570
Net cash provided by (used in) financing activities													42,939	14,040	(34,738)
Net Change in Cash and Cash Equivalents													(8,660)	4,290	(7,493)
Cash and Cash Equivalents, Beginning of Period				29,575				25,285				32,778	29,575	25,285	32,778
Cash and Cash Equivalents, End of Period	20,915				29,575				25,285				20,915	29,575	25,285
MutualFirst Financial, Inc. [Member]
Operating Activities
Net income													12,262	11,046	9,383
Item not requiring cash
ESOP shares earned															474
Deferred income tax													(102)	159	71
(Equity in undistributed income) distributions in excess of income of subsidiary													(9,252)	(8,202)	20,619
Other													13	19	(365)
Net cash provided by operating activities													2,921	3,022	30,182
Investing Activities
Investment in subsidiary													(250)
Net cash provided by (used in) investing activities													(250)
Financing Activities
Repayments of other borrowings													(759)	(759)	(759)
Stock repurchased															(28,924)
Cash dividends													(3,550)	(2,297)	(2,953)
Proceeds from stock options exercised													2,011	1,347	570
Net cash provided by (used in) financing activities													(2,298)	(1,709)	(32,066)
Net Change in Cash and Cash Equivalents													373	1,313	(1,884)
Cash and Cash Equivalents, Beginning of Period				$ 2,383				$ 1,070				$ 2,954	2,383	1,070	2,954
Cash and Cash Equivalents, End of Period	$ 2,756				$ 2,383				$ 1,070				$ 2,756	$ 2,383	$ 1,070