XML 55 R42.htm IDEA: XBRL DOCUMENT v3.20.4
Summary of Significant Accounting Policies - Trade Accounts Receivable (Details) - USD ($)
$ in Thousands
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Trade Accounts Receivable      
Trade accounts receivable $ 44,305 $ 39,004  
Unbilled accounts receivable 10,576 4,223  
Trade and unbilled accounts receivable 54,881 43,227  
Less allowance for doubtful accounts (289) (395) $ (211)
Accounts receivable, net $ 54,592 $ 42,832