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Business Segments, Geographic Data, and Sales by Major Customers - Additional Information (Detail)
6 Months Ended 12 Months Ended
Jun. 30, 2017
Segment
Customer
Dec. 31, 2016
Segment
Customer
Segment Reporting Information [Line Items]    
Number of reporting segments | Segment 3 3
Number of major customers | Customer 3 3
Net Accounts Receivable | Three Largest Customers | Customer Concentration Risk    
Segment Reporting Information [Line Items]    
Percentage of net accounts receivable accounted for by three largest customers 42.90% 35.80%