Income Taxes - Unrecognized Tax Benefits (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Tax Disclosure [Abstract]
Balance at beginning of year	$ 571,194	$ 457,106
Additions based on tax positions related to the current year	337,862	141,866	$ 97,412
Additions for tax positions of prior years	72,324		359,694
Reductions for tax positions of prior years		(27,778)
Settlement of tax audits		0	0
Reductions due to lapsed statute of limitations		0	0
Balance at end of year	$ 981,380	$ 571,194	$ 457,106