Annual report pursuant to Section 13 and 15(d)

Cash, Cash Equivalents and Investments - Cash Equivalents and Investments Carried at Fair Value (Details)

v3.20.1
Cash, Cash Equivalents and Investments - Cash Equivalents and Investments Carried at Fair Value (Details) - USD ($)
$ in Thousands
Dec. 31, 2019
Dec. 31, 2018
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Money market funds, included in cash equivalents $ 47,384 $ 7,791
Corporate bonds, included in cash equivalents   10,910
Investments - US treasuries 5,300 7,518
Investments - Asset-backed securities 7,950 5,758
Investments - Corporate bonds 28,644 39,964
Total 89,278 71,941
Quoted prices in active markets (Level 1)    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Money market funds, included in cash equivalents 47,384 7,791
Corporate bonds, included in cash equivalents   0
Investments - US treasuries 5,300 7,518
Investments - Asset-backed securities 0 0
Investments - Corporate bonds 0 0
Total 52,684 15,309
Significant other observable inputs (Level 2)    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Money market funds, included in cash equivalents 0 0
Corporate bonds, included in cash equivalents   10,910
Investments - US treasuries 0 0
Investments - Asset-backed securities 7,950 5,758
Investments - Corporate bonds 28,644 39,964
Total 36,594 56,632
Significant unobservable inputs (Level 3)    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Money market funds, included in cash equivalents 0 0
Corporate bonds, included in cash equivalents   0
Investments - US treasuries 0 0
Investments - Asset-backed securities 0 0
Investments - Corporate bonds 0 0
Total $ 0 $ 0