Quarterly report pursuant to Section 13 or 15(d)

Cash, Cash Equivalents and Investments - Cash Equivalents and Investments (Details)

v3.10.0.1
Cash, Cash Equivalents and Investments - Cash Equivalents and Investments (Details)
$ in Thousands
 9 Months Ended
Sep. 30, 2018
USD ($)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]  
Amortized Cost $ 47,545
Unrealized gains 326
Unrealized losses (49)
Fair Value 47,822
U.S. treasuries  
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]  
Amortized Cost 2,702
Unrealized gains 0
Unrealized losses (8)
Fair Value $ 2,694
U.S. treasuries | Minimum  
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]  
Contractual maturity 46 days
U.S. treasuries | Maximum  
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]  
Contractual maturity 67 days
Asset-backed securities  
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]  
Amortized Cost $ 9,228
Unrealized gains 7
Unrealized losses (8)
Fair Value $ 9,227
Asset-backed securities | Minimum  
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]  
Contractual maturity 15 days
Asset-backed securities | Maximum  
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]  
Contractual maturity 319 days
Corporate bonds  
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]  
Amortized Cost $ 35,615
Unrealized gains 319
Unrealized losses (33)
Fair Value $ 35,901
Corporate bonds | Minimum  
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]  
Contractual maturity 1 day
Corporate bonds | Maximum  
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]  
Contractual maturity 207 days