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Summary of Significant Accounting Policies - Additional Information (Details) | 12 Months Ended |
--- | --- | ---
Dec. 31, 2019 USD ($) segment | Dec. 31, 2018 USD ($)
Significant Accounting Policies [Line Items] |  |
Variable Interest Entity, Qualitative or Quantitative Information, Ownership Percentage | 10.00% |
Number of Operating Segments | segment | 1 |
Accrued fees to authorized agents | $ 3,300,000 | $ 2,700,000
Loss Contingency Accrual | $ 0 |
Computers and equipment |  |
Significant Accounting Policies [Line Items] |  |
Property, Plant and Equipment, Useful Life | 5 years |
Computer software |  |
Significant Accounting Policies [Line Items] |  |
Property, Plant and Equipment, Useful Life | 3 years |
Furniture and fixtures |  |
Significant Accounting Policies [Line Items] |  |
Property, Plant and Equipment, Useful Life | 7 years |
Minimum | Leasehold improvements |  |
Significant Accounting Policies [Line Items] |  |
Property, Plant and Equipment, Useful Life | 3 years |
Maximum | Leasehold improvements |  |
Significant Accounting Policies [Line Items] |  |
Property, Plant and Equipment, Useful Life | 14 years |

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- Definition Amount of loss contingency liability. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 450 -SubTopic 20 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=118942415&loc=d3e14326-108349 + Details
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- Definition Number of operating segments. An operating segment is a component of an enterprise: (a) that engages in business activities from which it may earn revenues and incur expenses (including revenues and expenses relating to transactions with other components of the same enterprise), (b) whose operating results are regularly reviewed by the enterprise's chief operating decision maker to make decisions about resources to be allocated to the segment and assess its performance, and (c) for which discrete financial information is available. An operating segment may engage in business activities for which it has yet to earn revenues, for example, start-up operations may be operating segments before earning revenues. + References No definition available. + Details
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- Definition Useful life of long lived, physical assets used in the normal conduct of business and not intended for resale, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. Examples include, but not limited to, land, buildings, machinery and equipment, office equipment, furniture and fixtures, and computer equipment. + References No definition available. + Details
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