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Receivables - Summary of Changes in Allowance for Doubtful Accounts (Details) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Receivables [Abstract]      
Balance at beginning of year $ 557 $ 607 $ 277
Increase in allowance charged to expense 1,210 362 611
Accounts charged against the allowance, net of recoveries (1,338) (412) (281)
Balance at end of year $ 429 $ 557 $ 607