Investment Securities - Summary of Recognized Gain and Losses on Sale of Investment Securities (Detail) - USD ($)	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015
Schedule Of Gain Loss On Investments Including Marketable Securities And Investments Held At Cost Income Statement Reported Amounts Summary [Line Items]
Proceeds from Sale of Investment Securities	$ 6,252,362	$ 2,919,958
Gain (Loss) recognized in Statement of Operations on the Disposition of Securities	(575,567)	285,705
Debt Securities
Schedule Of Gain Loss On Investments Including Marketable Securities And Investments Held At Cost Income Statement Reported Amounts Summary [Line Items]
Proceeds from Sale of Investment Securities	827,738	2,084,994
Cost Basis of Securities Sold	(843,951)	(1,930,080)
Gain (Loss) recognized in Statement of Operations on the Disposition of Securities	(16,213)	154,914
Equity Securities
Schedule Of Gain Loss On Investments Including Marketable Securities And Investments Held At Cost Income Statement Reported Amounts Summary [Line Items]
Proceeds from Sale of Investment Securities	5,424,624	834,964
Cost Basis of Securities Sold	(5,983,978)	(704,173)
Gain (Loss) recognized in Statement of Operations on the Disposition of Securities	$ (559,354)	$ 130,791