Income Taxes - Components of Net Deferred Tax Assets and Liabilities (Detail) (USD $)	Dec. 31, 2013	Dec. 31, 2012
Deferred tax assets
Allowance for loan losses	$ 631,641	$ 747,792
Interest on non-accrual loans	40,495	120,356
Mortgage servicing rights	196,909
Other real estate	476,496	236,610
Pension plan		3,276
Postretirement benefits	206,429	258,231
Deferred compensation	113,712	84,879
Stock-based compensation	18,301	10,215
Alternative minimum tax credit	96,428	174,997
Unrealized losses on available-for-sale securities	407,964
Other	2,913	272,942
Total deferred tax assets	2,191,288	1,909,298
Deferred tax liabilities
Unrealized gains on available-for-sale securities		(143,828)
Pension plan	(27,120)
Depreciation	(276,066)	(305,010)
Amortization of goodwill	(896,451)	(860,950)
Net deferred loan fees and costs	(171,882)	(238,732)
Other	(63,925)	(63,591)
Total deferred tax (liabilities)	(1,435,444)	(1,612,111)
Net deferred tax assets	$ 755,844	$ 297,187