Quarterly report pursuant to Section 13 or 15(d)

Cash, Cash Equivalents and Short-Term Investments - Gross Unrealized Gains and Losses (Details)

v3.19.2
Cash, Cash Equivalents and Short-Term Investments - Gross Unrealized Gains and Losses (Details) - USD ($)
$ in Thousands
Jun. 30, 2019
Dec. 31, 2018
Cash equivalents and available-for-sale securities    
Amortized Cost $ 100,181 $ 116,830
Fair Value 100,224 116,805
Gross Unrealized Gains    
Cash equivalents and available-for-sale securities    
Gross Unrealized Gains (Losses) 51 2
Gross Unrealized Losses    
Cash equivalents and available-for-sale securities    
Gross Unrealized Gains (Losses) (8) (27)
Government-sponsored enterprises securities    
Cash equivalents and available-for-sale securities    
Amortized Cost 4,995 7,873
Fair Value 4,997 7,872
Government-sponsored enterprises securities | Gross Unrealized Gains    
Cash equivalents and available-for-sale securities    
Gross Unrealized Gains (Losses) 2  
Government-sponsored enterprises securities | Gross Unrealized Losses    
Cash equivalents and available-for-sale securities    
Gross Unrealized Gains (Losses)   (1)
Corporate bonds and commercial paper    
Cash equivalents and available-for-sale securities    
Amortized Cost 95,186 108,957
Fair Value 95,227 108,933
Corporate bonds and commercial paper | Gross Unrealized Gains    
Cash equivalents and available-for-sale securities    
Gross Unrealized Gains (Losses) 49 2
Corporate bonds and commercial paper | Gross Unrealized Losses    
Cash equivalents and available-for-sale securities    
Gross Unrealized Gains (Losses) $ (8) $ (26)