Employee Benefits - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Postemployment Benefits [Abstract]
Defined contribution plan, Employees voluntary contributions, Amount	$ 164,989	$ 130,769	$ 92,562
Eligibility criteria for employees to participate in the plan	Employees are eligible to participate in the plan beginning on the first day of employment.