XML 28 R35.htm IDEA: XBRL DOCUMENT v3.20.1
4. Patents (Details) - USD ($)
$ in Thousands
Mar. 31, 2020
Dec. 31, 2019
Goodwill and Intangible Assets Disclosure [Abstract]    
Future amortization, remainder of 2020 $ 2,571  
Future amortization, 2021 2,851  
Future amortization, 2022 2,851  
Future amortization, 2023 2,776  
Future amortization, 2024 1,405  
Future amortization, Thereafter 96  
Patents, net $ 12,550 $ 7,814