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Summary of Significant Accounting Policies - Narrative (Details) | 3 Months Ended | 9 Months Ended |  |  |  |
--- | --- | --- | --- | --- | --- | ---
Sep. 30, 2020 USD ($) | Sep. 30, 2019 USD ($) | Sep. 30, 2020 USD ($) segment | Sep. 30, 2019 USD ($) | Dec. 31, 2020 USD ($) | Dec. 31, 2019 USD ($) | Dec. 31, 2018 USD ($) | Dec. 31, 2016 USD ($)
New Accounting Pronouncement, Early Adoption [Line Items] |  |  |  |  |  |  |  |
Restricted cash | $ 100,000 |  | $ 100,000 |  |  | $ 100,000 |  |
Joint venture quarterly promotion fee cap | 5.00% |  | 5.00% |  |  |  |  |
Revenue | $ 10,775,000 | $ 10,439,000 | $ 29,307,000 | $ 30,173,000 |  |  |  |
Advertising Expense | 300,000 | 400,000 | $ 900,000 | 1,100,000 |  |  |  |
Cost of revenue |  | 400,000 |  | 1,100,000 |  |  |  |
Number of operating segments | segment |  |  | 1 |  |  |  |  |
Janssen (SIMPONI) |  |  |  |  |  |  |  |
New Accounting Pronouncement, Early Adoption [Line Items] |  |  |  |  |  |  |  |
Revenue | 1,300,000 | $ 400,000 | $ 3,400,000 | $ 800,000 |  |  |  |
Forecast |  |  |  |  |  |  |  |
New Accounting Pronouncement, Early Adoption [Line Items] |  |  |  |  |  |  |  |
Joint venture quarterly promotion fee cap |  |  |  |  | 5.00% |  |  |
Minimum |  |  |  |  |  |  |  |
New Accounting Pronouncement, Early Adoption [Line Items] |  |  |  |  |  |  |  |
Joint venture, quarterly promotion fee per prescription |  |  |  |  |  |  | $ 750 |
Joint venture, quarterly promotion fee | 300,000 |  | 300,000 |  |  |  |  |
Minimum | Forecast |  |  |  |  |  |  |  |
New Accounting Pronouncement, Early Adoption [Line Items] |  |  |  |  |  |  |  |
Joint venture, quarterly promotion fee |  |  |  |  | $ 300,000 |  |  |
Maximum |  |  |  |  |  |  |  |
New Accounting Pronouncement, Early Adoption [Line Items] |  |  |  |  |  |  |  |
Joint venture, quarterly promotion fee per prescription |  |  |  |  |  |  | $ 1,250 |
Other assets |  |  |  |  |  |  |  |
New Accounting Pronouncement, Early Adoption [Line Items] |  |  |  |  |  |  |  |
Restricted cash |  |  |  |  |  |  |  | $ 100,000
Shipping and Handling |  |  |  |  |  |  |  |
New Accounting Pronouncement, Early Adoption [Line Items] |  |  |  |  |  |  |  |
Cost of revenue | $ 400,000 |  | $ 1,100,000 |  |  |  |  |
Revenue Benchmark | Product Concentration Risk | AVISE CTD Test |  |  |  |  |  |  |  |
New Accounting Pronouncement, Early Adoption [Line Items] |  |  |  |  |  |  |  |
Percent of total revenue | 68.00% | 83.00% | 71.00% | 83.00% |  |  |  |
Revenue Benchmark | Supplier Concentration Risk | Two Suppliers |  |  |  |  |  |  |  |
New Accounting Pronouncement, Early Adoption [Line Items] |  |  |  |  |  |  |  |
Percent of total revenue | 98.00% | 97.00% | 97.00% | 96.00% |  |  |  |

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