Summary of Significant Accounting Policies - Summary of Intangible Asset, Net of Accumulated Impairment Charges (Detail) - USD ($)
$ in Thousands
Dec. 31, 2015
Dec. 31, 2014
Finite-Lived Intangible Assets [Line Items]    
Cost $ 630 $ 630
Accumulated Impairment (430) (120)
Net Book Value 200 510
IPR&D [Member]    
Finite-Lived Intangible Assets [Line Items]    
Cost 630 630
Accumulated Impairment (430) (120)
Net Book Value $ 200 $ 510