XML 66 R51.htm IDEA: XBRL DOCUMENT v3.19.1
Marketable Securities and Fair Value Measurements - Assumptions Used to Estimate Fair Value of Common Stock Warrants (Details)
Dec. 31, 2017
year
$ / shares
Risk-free interest rate  
Fair Value Measurement Inputs and Valuation Techniques [Line Items]  
Warrants and Rights Outstanding, Measurement Input 0.0175
Expected volatility  
Fair Value Measurement Inputs and Valuation Techniques [Line Items]  
Warrants and Rights Outstanding, Measurement Input 0.55
Expected life in years  
Fair Value Measurement Inputs and Valuation Techniques [Line Items]  
Warrants and Rights Outstanding, Measurement Input | year 0.70
Dividend yield  
Fair Value Measurement Inputs and Valuation Techniques [Line Items]  
Warrants and Rights Outstanding, Measurement Input | $ / shares 0