Restructuring Costs - Additional Information (Detail) $ in Thousands	1 Months Ended		3 Months Ended	6 Months Ended
	Oct. 31, 2019 Employee	May 31, 2019 Employee	Mar. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)
Restructuring Cost And Reserve [Line Items]
Restructuring costs paid			$ 428
Accrued restructuring charges			44	$ 472
Severance Plan [Member]
Restructuring Cost And Reserve [Line Items]
Number of workforce elimination | Employee		38
Severance Plan [Member] | Taiwan
Restructuring Cost And Reserve [Line Items]
Number of workforce expected to be eliminated | Employee	17
Severance and Benefits and Non-cash Impairment Charge [Member]
Restructuring Cost And Reserve [Line Items]
Aggregate restructuring charges			2,300
Restructuring costs				$ 0
Restructuring costs paid			400
Accrued restructuring charges			$ 100