Prepaid Expenses And Other Current Assets (Detail) (USD $)
In Thousands, unless otherwise specified
Dec. 31, 2014
Dec. 31, 2013
Prepaid Expense and Other Assets [Line Items]    
Prepaid Insurance $ 248 $ 346
Prepaid patent costs 159 127
Other prepaid expenses 48 52
Total prepaid expenses and other current assets $ 455 $ 525