Restructuring Costs - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Restructuring Cost And Reserve [Line Items]
Separation costs	$ 526	$ 1,838	$ 206	$ 4,069
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			$ 2,900	6,000
Separation costs	$ 526	$ 1,838	206	4,069
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			$ 2,900	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