XML 45 R24.htm IDEA: XBRL DOCUMENT v3.20.1
Summary of Significant Accounting Policies - Short-Term Investments (Details) - Corporate debt securities - USD ($)
$ in Thousands
Mar. 31, 2020
Dec. 31, 2019
Cash and Cash Equivalents [Line Items]    
Cost $ 5,285 $ 9,284
Amortization/ Accretion 4 5
Unrealized Gains/(Losses)   (4)
Estimated Fair Value $ 5,289 $ 9,285