Post-effective amendment to a registration statement that is not immediately effective upon filing

ACCOUNTS RECEIVABLE - Allowance for doubtful accounts (Details)

v3.21.1
ACCOUNTS RECEIVABLE - Allowance for doubtful accounts (Details) - USD ($)
$ in Thousands
3 Months Ended 12 Months Ended
Mar. 31, 2021
Dec. 31, 2020
Dec. 31, 2019
ACCOUNTS RECEIVABLE      
Balance at beginning of period $ 500 $ 199  
Provision for uncollectible accounts 72 377 $ 199
Uncollectible accounts written off (208) (76)  
Balance at end of period $ 364 $ 500 $ 199