Income Taxes - Unrecognized Tax Benefits (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Tax Disclosure [Abstract]
Beginning Balance	$ 672,000	$ 353,000	$ 239,000
Additions based on tax positions taken during the current period	401,000	222,000	134,000
Reductions based on tax positions taken during the prior period	(50,000)	(47,000)	(20,000)
Additions based on tax positions taken during a prior period	131,000	144,000	0
Ending Balance	$ 1,154,000	$ 672,000	$ 353,000