Quarterly report pursuant to Section 13 or 15(d)

Summary of Significant Accounting Policies - Schedule of Fair Value of Financial Instruments (Details)

v3.19.1
Summary of Significant Accounting Policies - Schedule of Fair Value of Financial Instruments (Details) - USD ($)
$ in Thousands
Mar. 31, 2019
Dec. 31, 2018
Fair Value of Marketable debt Securities $ 4,229 $ 6,687
Level 1 [Member]    
Fair Value of Marketable debt Securities
Level 2 [Member]    
Fair Value of Marketable debt Securities 4,229 6,687
Level 3 [Member]    
Fair Value of Marketable debt Securities
U.S. Government Obligations [Member]    
Fair Value of Marketable debt Securities 427 2,398
U.S. Government Obligations [Member] | Level 1 [Member]    
Fair Value of Marketable debt Securities
U.S. Government Obligations [Member] | Level 2 [Member]    
Fair Value of Marketable debt Securities 427 2,398
U.S. Government Obligations [Member] | Level 3 [Member]    
Fair Value of Marketable debt Securities
Corporate Obligations [Member]    
Fair Value of Marketable debt Securities 3,802 4,289
Corporate Obligations [Member] | Level 1 [Member]    
Fair Value of Marketable debt Securities
Corporate Obligations [Member] | Level 2 [Member]    
Fair Value of Marketable debt Securities 3,802 4,289
Corporate Obligations [Member] | Level 3 [Member]    
Fair Value of Marketable debt Securities