Quarterly report pursuant to Section 13 or 15(d)

Fair Value Measurements (Warrants Outstanding) (Details)

v3.20.2
Fair Value Measurements (Warrants Outstanding) (Details) - USD ($)
$ / shares in Units, $ in Thousands
3 Months Ended 9 Months Ended
Sep. 30, 2020
Sep. 30, 2019
Sep. 30, 2020
Sep. 30, 2019
May 01, 2020
Class of Warrant or Right [Line Items]          
Change in fair value $ (332) $ 973 $ (730) $ (752)  
Class of Warrant or Right, Outstanding 414,286   414,286    
ESW Holdings, Inc.          
Class of Warrant or Right [Line Items]          
Class of Warrant or Right, Outstanding         925,000
Class of Warrant or Right, Exercise Price of Warrants or Rights         $ 1.96
Hale Capital, LLP          
Class of Warrant or Right [Line Items]          
Class of Warrant or Right, Outstanding 314,286   314,286    
Class of Warrant or Right, Exercise Price of Warrants or Rights $ 2.80   $ 2.80    
Warrants and Rights Outstanding, Maturity Date Oct. 21, 2026   Oct. 21, 2026    
iStudy Co., Ltd.          
Class of Warrant or Right [Line Items]          
Class of Warrant or Right, Outstanding 100,000   100,000    
Class of Warrant or Right, Exercise Price of Warrants or Rights $ 2.43   $ 2.43    
Warrants and Rights Outstanding, Maturity Date Aug. 31, 2028   Aug. 31, 2028    
Derivative          
Class of Warrant or Right [Line Items]          
Change in fair value $ (1)