401(k) Savings Plan - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Compensation And Retirement Disclosure [Abstract]
Defined benefit plan, employees' contribution in percentage, maximum	87.00%
Employer's contribution to 401 (k) defined contribution saving plan	$ 0.5	$ 0.5	$ 0.5