Actual Capital Amounts and Ratios (Parenthetical) (Detail) (USD $)	Dec. 31, 2012
MutualFirst Consolidated
Compliance with Regulatory Capital Requirements for Mortgage Companies [Line Items]
Tier 1 Capital to Average Total Assets	$ 1,400,000,000
Tier 1 Capital to Risk-Weighted Assets	956,200,000
MutualBank
Compliance with Regulatory Capital Requirements for Mortgage Companies [Line Items]
Tier 1 Capital to Average Total Assets	1,400,000,000
Tier 1 Capital to Risk-Weighted Assets	$ 955,400,000