XML 19 R3.htm IDEA: XBRL DOCUMENT v3.20.4
Consolidated Statements of Operations (Parentheticals) - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Income Statement [Abstract]      
Interest income $ 264 $ 745 $ 1,290