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Income Taxes - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Taxes [Line Items]
Gross tax research other tax credit carryforwards	$ 58.9
Accrued interest on unrecognized tax benefits	0.7	$ 0.5	$ 0.6
Net unrecognized tax benefits, excluding interest and penalties, related to foreign tax positions	4.3
Change in valuation allowance	$ 3.3	$ 9.4	$ 4.3
Benefits of the tax holiday per share	$ 0.03	$ 0.04
Inland Revenue, Singapore (IRAS) [Member]
Income Taxes [Line Items]
Benefits of the tax holiday	$ 1.7	$ 2.2
Indefinite [Member]
Income Taxes [Line Items]
Gross tax research other tax credit carryforwards	$ 13.7
Federal State and Foreign [Member]
Income Taxes [Line Items]
Tax credit expiration period	2037
Federal State and Foreign [Member] \| Indefinite [Member]
Income Taxes [Line Items]
Operating loss carry forwards	$ 50.9
Federal State and Foreign [Member] \| 2017 [Member]
Income Taxes [Line Items]
Operating loss carry forwards	$ 97.0