Income Taxes - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Tax [Line Items]
Deferred Tax Liabilities, Net	$ 11,923	$ 11,526
Deferred Tax Assets, Valuation Allowance	17,494	14,661
Unrecognized tax benefits that would impact effective tax rate	9,900
Accrued interest and penalties related to unrecognized tax benefits	1,000	700
Interest and penalties recognized in the statement of operations	300	100	$ 100
Gross unrecognized tax benefit decrease within next twelve months	1,800
State
Income Tax [Line Items]
State operating loss carryforwards	$ 7,900
Operating loss carryforwards, expiration date	Dec. 31, 2019
Year Which Prior Year's Tax Returns Are No Longer Subject to Tax Examination	Dec. 31, 2013
Foreign
Income Tax [Line Items]
Deferred Tax Assets, Valuation Allowance	$ 6,900	5,000
Net deferred tax assets	$ 10,700	6,600
Operating loss carryforwards, expiration date	Dec. 31, 2018
Foreign operating loss carryforwards	$ 25,000
Year Which Prior Year's Tax Returns Are No Longer Subject to Tax Examination	Dec. 31, 2011
U.S.
Income Tax [Line Items]
Deferred Tax Liabilities, Net	$ 5,100	3,500
Deferred Tax Assets, Valuation Allowance	$ 10,600	9,600
Year Which Prior Year's Tax Returns Are No Longer Subject to Tax Examination	Dec. 31, 2013
Malaysia
Income Tax [Line Items]
Income tax benefit estimate attributable to the tax status of subsidiary			$ 10,200
Income tax expense benefit per diluted share			$ 0.07
additional effective tax rate benefit	$ 2,000	4,300	$ 4,400
Korea Tax Authority [Member]
Income Tax [Line Items]
Income tax benefit estimate attributable to the tax status of subsidiary	$ 7,400	$ 3,300	$ 1,500
Income tax expense benefit per diluted share	$ 0.05	$ 0.02	$ 0.01
additional effective tax rate benefit	$ 4,300	$ 1,900	$ 900
Inland Revenue, Singapore (IRAS) [Member]
Income Tax [Line Items]
Income tax benefit estimate attributable to the tax status of subsidiary	$ 4,700	$ 2,300	$ 1,700
Income tax expense benefit per diluted share	$ 0.03	$ 0.02	$ 0.01
additional effective tax rate benefit	$ 12,400	$ 6,500	$ 4,600