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Income Taxes - Additional Information (Detail) - USD ($) $ in Thousands |  | 12 Months Ended |
--- | --- | --- | ---
Dec. 31, 2020 | Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018 | Dec. 31, 2017
Tax Credit Carryforward [Line Items] |  |  |  |  |
Change in valuation allowance |  | $ 2,708 | $ (1,933) |  |
Accumulated undistributed earnings from a foreign subsidiary | $ 370,000 | 370,000 |  |  |
Deferred tax liability on undistributed foreign earnings | 0 | 0 |  |  |
Unrecognized tax benefit | 19,001 | 19,001 | 20,655 | $ 18,707 | $ 15,056
Total amount of interest expense and penalties |  | 430 | 319 | $ 776 |
Total amount of accrued interest and penalties | 5,179 | $ 5,179 | $ 4,511 |  |
Cayman Islands Tax Information Authority [Member] |  |  |  |  |
Tax Credit Carryforward [Line Items] |  |  |  |  |
Corporate income tax rate |  | 0.00% | 0.00% | 0.00% |
Foreign Tax Authority | Internal Revenue Service (IRS) [Member] | Tax Year 2017 [Member] |  |  |  |  |
Tax Credit Carryforward [Line Items] |  |  |  |  |
Net operating loss carryforwards for income tax purposes | 36,823 | $ 36,823 |  |  |
Foreign Tax Authority | Internal Revenue Service (IRS) [Member] | Tax Year 2018 [Member] |  |  |  |  |
Tax Credit Carryforward [Line Items] |  |  |  |  |
Net operating loss carryforwards for income tax purposes | $ 12,244 | $ 12,244 |  |  |
Operating loss carryforward expiration year description | carryforward indefinitely |  |  |  |
Foreign Tax Authority | Maximum | Internal Revenue Service (IRS) [Member] | Tax Year 2017 [Member] |  |  |  |  |
Tax Credit Carryforward [Line Items] |  |  |  |  |
Federal net operating loss carryforwards expiration year |  | 2037 |  |  |
Foreign Tax Authority | Research And Development | Internal Revenue Service (IRS) [Member] |  |  |  |  |
Tax Credit Carryforward [Line Items] |  |  |  |  |
Deferred tax assets tax credit carryforwards | $ 2,659 | $ 2,659 |  |  |
Tax credit carryforward expiration year for federal |  | 2040 |  |  |
State and Local Jurisdiction [Member] | Minimum | Internal Revenue Service (IRS) [Member] | Tax Year 2017 [Member] |  |  |  |  |
Tax Credit Carryforward [Line Items] |  |  |  |  |
Federal net operating loss carryforwards expiration year |  | 2021 |  |  |
State and Local Jurisdiction [Member] | Research And Development |  |  |  |  |
Tax Credit Carryforward [Line Items] |  |  |  |  |
Deferred tax assets tax credit carryforwards | $ 1,853 | $ 1,853 |  |  |
Tax credit carryforward expiration year for state |  | no expiration date in California |  |  |

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