Employee Benefit Plans - Components of Net Periodic Benefit Cost (Detail) (USD $)	6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012
Defined Benefit Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost		$ 127,142
Interest cost	71,630	89,149
Expected return on plan assets	(107,331)	(160,932)
Amortization of unrecognized prior service cost		(26,981)
Amortization of unrecognized net loss	44,873	35,720
Amortization of transition obligation		112,313
Net periodic benefit cost	9,172	176,411
Post Retirement Benefit Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	11,475	13,001
Interest cost	14,953	14,978
Amortization of unrecognized net loss	2,248	1,457
Amortization of transition obligation	1,457	1,471
Net periodic benefit cost	$ 30,133	$ 30,907