Business Segments, Geographic Data, Sales by Product Group and Major Customers - Additional Information (Detail)	9 Months Ended	12 Months Ended
	Sep. 30, 2016 Segment Customer	Dec. 31, 2015 Customer
Segment Reporting Information [Line Items]
Number of reporting segments | Segment	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	46.70%	56.20%