Annual report pursuant to Section 13 and 15(d)

Segments - Schedule of Activities with Major Customers (Detail)

v3.7.0.1
Segments - Schedule of Activities with Major Customers (Detail)
$ in Thousands
 12 Months Ended
Dec. 31, 2016
USD ($)
customer
Dec. 31, 2015
USD ($)
Dec. 31, 2014
Segment Reporting [Abstract]      
Number of major customers | customer 2    
Panasonic | Customer Concentration Risk | Consolidated Revenue      
Revenue, Major Customer      
Percent of consolidated revenue 21.60% 21.00% 17.70%
Panasonic | Customer Concentration Risk | Accounts Receivable      
Revenue, Major Customer      
Accounts receivable $ 17,126 $ 14,433  
Boeing | Customer Concentration Risk | Consolidated Revenue      
Revenue, Major Customer      
Percent of consolidated revenue 15.20% 13.00% 14.10%
Boeing | Customer Concentration Risk | Accounts Receivable      
Revenue, Major Customer      
Accounts receivable $ 11,737 $ 9,598