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Income Taxes - Additional Information (Detail) - USD ($) | 12 Months Ended
--- | ---
Dec. 31, 2018 | Dec. 31, 2017 | Dec. 31, 2016
Income Taxes [Line Items] |  |  |
Increase in valuation allowance | $ 34,400,000 | $ 30,500,000 | $ 12,300,000
Federal and state net operating loss carryforwards | 91,683,000 | 71,256,000 |
Foreign net operating loss carryforwards | $ 21,295,000 | $ 15,052,000 |
Tax at statutory federal rate | 21.00% | 34.00% | 34.00%
Percentage of ownership changes | 0.00% |  |
Unrecognized tax benefits | $ 28,000,000 |  |
Unrecognized tax benefits that would affect effective tax rate | 500,000 |  |
Accrued interest, unrecognized tax benefits | $ 0 |  | $ 0
Unrecognized tax benefits description | The Company does not anticipate a material change to its unrecognized tax benefits over the next twelve months that would affect the Company’s effective tax rate. |  |
Earliest Tax Year [Member] |  |  |
Income Taxes [Line Items] |  |  |
Foreign statute of limitation generally remains open in the year | 2009 |  |
Latest Tax Year [Member] |  |  |
Income Taxes [Line Items] |  |  |
Foreign statute of limitation generally remains open in the year | 2018 |  |
ASU 2016-09 [Member] |  |  |
Income Taxes [Line Items] |  |  |
Increase in valuation allowance | $ 19,500,000 |  |
Retrospective increase in deferred tax assets for previously unrecognized excess tax benefits | 19,500,000 |  |
Maximum [Member] |  |  |
Income Taxes [Line Items] |  |  |
Tax at statutory federal rate |  | 35.00% |
Foreign net operating loss [Member] |  |  |
Income Taxes [Line Items] |  |  |
Foreign net operating loss carryforwards | $ 86,300,000 |  |
Foreign net operating loss [Member] | Minimum [Member] |  |  |
Income Taxes [Line Items] |  |  |
Operating loss carryforwards expiration year | 2019 |  |
Foreign net operating loss [Member] | Maximum [Member] |  |  |
Income Taxes [Line Items] |  |  |
Operating loss carryforwards expiration year | 2028 |  |
Federal [Member] |  |  |
Income Taxes [Line Items] |  |  |
Federal and state net operating loss carryforwards | $ 400,300,000 |  |
Operating loss carryforwards expiration year | 2026 |  |
Other tax credit carryforwards | $ 46,400,000 |  |
Other tax credit carryforwards expiration year | 2019 |  |
State [Member] |  |  |
Income Taxes [Line Items] |  |  |
Federal and state net operating loss carryforwards | $ 148,100,000 |  |
Operating loss carryforwards expiration year | 2019 |  |
State [Member] | California [Member] |  |  |
Income Taxes [Line Items] |  |  |
Other tax credit carryforwards | $ 26,300,000 |  |

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