Quarterly report pursuant to Section 13 or 15(d)

Summary of Significant Accounting Policies - Summary of Components of Marketable Securities (Details)

v3.19.1
Summary of Significant Accounting Policies - Summary of Components of Marketable Securities (Details) - USD ($)
$ in Thousands
Mar. 31, 2019
Dec. 31, 2018
Amortized Cost $ 4,238 $ 6,711
Unrealized Losses (9) (24)
Market Value 4,229 6,687
U.S. Treasuries [Member]    
Amortized Cost 430 2,401
Unrealized Losses (3) (3)
Market Value 427 2,398
Corporate Bonds [Member]    
Amortized Cost 3,808 4,310
Unrealized Losses (6) (21)
Market Value $ 3,802 $ 4,289