Commitments - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Commitments and Contingencies Disclosure [Abstract]
Lease expense	$ 900,000	$ 1,000,000	$ 900,000
Minimum purchase commitments or payments under agreements	$ 0