Employee Incentive Plans - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Compensation And Retirement Disclosure [Abstract]
Maximum percentage of eligible compensation to be contributed by the employees	15.00%
Maximum percentage of matching contribution by the company	50.00%
Percentage of employee's compensation up to which the employee may contribute	6.00%
Contributions vest over period	5 years
Contributions by employer	$ 488	$ 484	$ 350