Financial Instruments (Tables)
 12 Months Ended
Dec. 31, 2016
Investments, All Other Investments [Abstract]  
Summary of Financial Assets and Liabilities Measured at Fair Value on Recurring Basis

The following table provides a summary of the financial assets and liabilities measured at fair value on a recurring basis as follows: (in thousands):

 

            Fair Value Measurements at December 31, 2016 Using  

Description

    Balance as of
December 31,
2016		      Quoted Prices in Active
Markets for Identical
Assets (Level 1)		      Significant Other
Observable Inputs
(Level 2)		      Significant
Unobservable
Inputs (Level 3)		  

Warrant liabilities

    $ 1,004      $ —        $ —        $ 1,004  
            Fair Value Measurements at December 31, 2015 Using  

Description

    Balance as of
December 31,
2015		      Quoted Prices in Active
Markets for Identical
Assets (Level 1)		      Significant Other
Observable Inputs
(Level 2)		      Significant
Unobservable
Inputs (Level 3)		  

Warrant liabilities

    $ 649      $ —        $ —        $ 649  
Fair Value of Warrants Based on Historical Volatilities

the following inputs were used at December 31, 2016:

 

     Expected Volatility     Risk-Free Interest Rate     Expected Life  

Warrants with one year or less remaining term

      60.81 %      0.51 %      0.2 year  
Roll-Forward of Fair Value Measurements Using Significant Unobservable Inputs (Level 3) for Warrants

A roll-forward of fair value measurements using significant unobservable inputs (Level 3) for the warrants is as follows (in thousands):

 

     Year ended
December 31, 2016		  
  

Balance January 1, 2016

    $ 649  

Settlements from exercise

      (202 ) 

Expense for the period

      557  
  

 

 

  

Balance December 31, 2016

    $ 1,004