Actual Capital Amounts and Ratios (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2012 MutualFirst Consolidated		Dec. 31, 2012 MutualBank
Compliance with Regulatory Capital Requirements for Mortgage Companies [Line Items]
Leverage Capital Level, Actual Capital Levels Amount		$ 125,770	[1]	$ 132,254	[1]
Total Risk-Based Capital Level, Actual Capital Levels Amount	130,450	137,764	[2]	144,247	[2]
Tier 1 Risk-Based Capital Level, Actual Capital Levels Amount	125,782	125,770	[3]	132,254	[3]
Core Capital (to adjusted total assets), Actual Capital Levels Amount	125,782
Core Capital (to adjusted tangible assets), Actual Capital Levels Amount	125,782
Tangible Capital, Actual Capital Levels Amount	125,782
Leverage Capital Level, Actual Capital Levels Ratio		8.80%	[1]	9.30%	[1]
Total Risk-Based Capital Level, Actual Capital Levels Ratio	14.30%	14.40%	[2]	15.10%	[2]
Tier 1 Risk-Based Capital Level, Actual Capital Levels Ratio	13.10%	13.20%	[3]	13.80%	[3]
Core Capital (to adjusted total assets), Actual Capital Levels Ratio	9.00%
Core Capital (to adjusted tangible assets), Actual Capital Levels Ratio	9.00%
Tangible Capital, Actual Capital Levels Ratio	9.00%
Leverage Capital Level, Minimum Regulatory Capital Ratios Amount		57,137	[1]	57,121	[1]
Total Risk-Based Capital Level, Minimum Regulatory Capital Ratios Amount	72,905	76,496	[2]	76,434	[2]
Tier 1 Risk-Based Capital Level, Minimum Regulatory Capital Ratios Amount	36,452	38,248	[3]	38,217	[3]
Core Capital (to adjusted total assets), Minimum Regulatory Capital Ratios Amount	56,200
Core Capital (to adjusted tangible assets), Minimum Regulatory Capital Ratios Amount	28,100
Tangible Capital, Minimum Regulatory Capital Ratios Amount	21,075
Leverage Capital Level, Minimum Regulatory Capital Ratios		4.00%	[1]	4.00%	[1]
Total Risk-Based Capital Level, Minimum Regulatory Capital Ratios	8.00%	8.00%	[2]	8.00%	[2]
Tier 1 Risk-Based Capital Level, Minimum Regulatory Capital Ratios	4.00%	4.00%	[3]	4.00%	[3]
Core Capital (to adjusted total assets), Minimum Regulatory Capital Ratios	4.00%
Core Capital (to adjusted tangible assets), Minimum Regulatory Capital Ratios	2.00%
Tangible Capital, Minimum Regulatory Capital Ratios	1.50%
Leverage Capital Level, Minimum Required To be Considered Well-Capitalized Amount				71,401	[1]
Total Risk-Based Capital Level, Minimum Required To be Considered Well-Capitalized Amount	91,131	95,620	[2]	95,543	[2]
Tier 1 Risk-Based Capital Level, Minimum Required To be Considered Well-Capitalized Amount	54,679	57,372	[3]	57,326	[3]
Core Capital (to adjusted total assets), Minimum Required To be Considered Well-Capitalized Amount	70,250
Core Capital (to adjusted tangible assets), Minimum Required To be Considered Well-Capitalized Amount
Tangible Capital, Minimum Required To be Considered Well-Capitalized Amount
Leverage Capital Level, Minimum Required To be Considered Well-Capitalized Ratio				5.00%
Total Risk-Based Capital Level, Minimum Required To be Considered Well-Capitalized Ratio	10.00%	10.00%		10.00%
Tier 1 Risk-Based Capital Level, Minimum Required To be Considered Well-Capitalized Ratio	6.00%	6.00%		6.00%
Core Capital (to adjusted total assets), Minimum Required To be Considered Well-Capitalized Ratio	5.00%
Core Capital (to adjusted tangible assets), Minimum Required To be Considered Well-Capitalized Ratio
Tangible Capital, Minimum Required To be Considered Well-Capitalized Ratio

[1] Tier 1 Capital to Average Total Assets of $1.4 billion for the Bank and $1.4 billion for the Company at December 31, 2012

[2] Total Capital to Risk-Weighted Assets.

[3] Tier 1 Capital to Risk-Weighted Assets of $955.4 million for the Bank and $956.2 million for the Company at December 31, 2012.