Retirement Plan - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Schedule Of Sale Of Subsidiary [Abstract]
Employers' sponsors contribution retirement plan	90.00%
Contribution to retirement plan, percentage of employee contribution	100.00%
Percentage of employee contribution to retirement plan	5.00%
Employers' sponsors contribution retirement plan amount	$ 0.2	$ 0.2	$ 0.2