Fair Value of FInancial Instruments - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest-bearing deposits maturing date	90 days
Business Combination, cost incurred	$ 231,400
Business Combination, Borrowings outstanding	0
Carrying amounts of dividends payable, number of days	Forty days
Impaired loans categorized as Level 3	1,843,000	2,440,000
Specific allocation for impaired loans	387,000	516,000
Asset impairment charges	0
Federal Home Loan Bank of Indianapolis [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Redemption period imposed on stock	5 years
Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans categorized as Level 3	1,500,000	1,900,000
Fair Value on a Recurring Basis [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Specific allocation for impaired loans	$ 386,900	$ 516,100