Fair Value Measurements - Fair Value Measurements (Detail) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Assets:
Restricted cash	$ 50	$ 50
Short-term investments	5,500
Fair Value, Measurements, Recurring [Member]
Assets:
Restricted cash	50	50
Cash equivalents	2,500	4,000
Short-term investments	5,500
Total	8,050	4,050
Fair Value, Measurements, Recurring [Member] | Other Significant Observable Inputs (Level 2) [Member]
Assets:
Restricted cash	50	50
Cash equivalents	2,500	4,000
Short-term investments	5,500
Total	$ 8,050	$ 4,050