Quarterly report pursuant to Section 13 or 15(d)

ACCOUNTS RECEIVABLE - Allowance for doubtful accounts (Details)

v3.21.2
ACCOUNTS RECEIVABLE - Allowance for doubtful accounts (Details) - USD ($)
$ in Thousands
9 Months Ended 12 Months Ended
Sep. 30, 2021
Sep. 30, 2020
Dec. 31, 2020
ACCOUNTS RECEIVABLE      
Balance at beginning of period $ 500 $ 199 $ 199
Provision for uncollectible accounts (316) $ (333) 377
Uncollectible accounts written off     (76)
Uncollectible accounts written off 195    
Balance at end of period $ 379   $ 500