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Summary of Significant Accounting Policies - Contract Balances (Details) - USD ($) $ in Thousands | Dec. 31, 2021 | Dec. 31, 2020
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Accounts Receivable |  |
Accounts receivable - contracts with customers | $ 3,354 | $ 3,243
Accounts receivable - ASC 842 | 8,164 | 9,802
Total Accounts Receivable | 11,518 | 13,045
Less: Allowance for doubtful accounts | (1,129) | (1,161)
Total Accounts Receivable, net | 10,389 | 11,884
Deferred income | $ 1,312 | $ 1,103

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