Income Taxes - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Income Tax Contingency [Line Items]
Income tax expenses (benefits)	$ (1,145)	$ 1,734	$ 836	$ 3,316
Income tax expenses	$ (7,316)	$ 12,510	$ 10,007	$ 40,973
Korean Subsidiary [Member]
Income Tax Contingency [Line Items]
The net operating income carry forwards of the taxable income	60.00%	60.00%	60.00%	60.00%

Amount of income (loss) from continuing operations, including income (loss) from equity method investments, before deduction of income tax expense (benefit), and income (loss) attributable to noncontrolling interest.

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