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Retirement Plan - Additional Information (Detail) - USD ($) $ in Millions | 3 Months Ended | 9 Months Ended
--- | --- | ---
Sep. 30, 2019 | Sep. 30, 2018 | Sep. 30, 2019 | Sep. 30, 2018
Defined Contribution Plan Disclosure [Line Items] |  |  |  |
Percentage of employer's contribution on employee's base salary |  |  | 3.00% |
Retirement 401K Plan [Member] |  |  |  |
Defined Contribution Plan Disclosure [Line Items] |  |  |  |
Contribution expense |  |  | $ 0.2 | $ 0.2
Retirement 401K Plan [Member] | Maximum [Member] |  |  |  |
Defined Contribution Plan Disclosure [Line Items] |  |  |  |
Contribution expense | $ 0.1 | $ 0.1 |  |

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- Definition Amount of cost for defined contribution plan. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 70 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=49170846&loc=d3e28014-114942 + Details
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- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
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- Definition Percentage of employees' gross pay for which the employer contributes a matching contribution to a defined contribution plan. + References No definition available. + Details
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- Details
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- Details
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