Restructuring Costs - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Restructuring Cost And Reserve [Line Items]
Separation costs	$ 2,039	$ 206	$ 6,108
KFAB Wafer Manufacturing Operations
Restructuring Cost And Reserve [Line Items]
Restructuring activities description		In February 2017, the Company announced its plan to transfer its wafer fabrication operation located in Lee’s Summit, MO. (“KFAB”) to other Company-owned wafer fabrication plants and external foundries. The Company ceased production operations at KFAB late in third quarter 2017 and vacated the premises in November 2017.
Proceeds from insurance settlement		$ 3,700	6,000
Separation costs	$ 2,039	206	6,108
KFAB Wafer Manufacturing Operations | Cost of Goods Sold
Restructuring Cost And Reserve [Line Items]
Proceeds from insurance settlement			4,200
KFAB Wafer Manufacturing Operations | Other Income
Restructuring Cost And Reserve [Line Items]
Proceeds from insurance settlement		$ 3,700	1,800
KFAB Wafer Manufacturing Operations | Cost of Goods Sold
Restructuring Cost And Reserve [Line Items]
Separation costs			500
KFAB Wafer Manufacturing Operations | Selling, General and Administrative Expense
Restructuring Cost And Reserve [Line Items]
Separation costs			90
KFAB Wafer Manufacturing Operations | Research and Development Expense
Restructuring Cost And Reserve [Line Items]
Separation costs			$ 20