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Basis of Presentation and Summary of Significant Accounting Policies Contract Balances (Details) - USD ($) $ in Thousands | 9 Months Ended | 12 Months Ended
--- | --- | ---
Sep. 30, 2018 | Dec. 31, 2017
Accounts Receivable |  |
Accounts receivable - contracts with customers | $ 5,313 | $ 5,454
Accounts receivable - non-ASC 606 | 3,208 | 3,649
Total Accounts Receivable | 8,521 | 9,103
Less:Allowance for doubtful accounts | (405) | (569)
Total Accounts Receivable, net | 8,116 | 8,534
Deferred income | 134 | 185
Revenue recognized | $ 176 | $ 1,900

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