Annual report pursuant to Section 13 and 15(d)

Segment Information - Additional Information (Detail)

v3.7.0.1
Segment Information - Additional Information (Detail)
$ in Thousands
3 Months Ended 12 Months Ended
Mar. 31, 2017
USD ($)
Customer
Dec. 31, 2016
USD ($)
Sep. 30, 2016
USD ($)
Jun. 30, 2016
USD ($)
Mar. 31, 2016
USD ($)
Customer
Dec. 31, 2015
USD ($)
Sep. 30, 2015
USD ($)
Jun. 30, 2015
USD ($)
Mar. 31, 2017
USD ($)
Segment
Customer
Mar. 31, 2016
USD ($)
Customer
Mar. 31, 2015
USD ($)
Customer
Segment Reporting Information [Line Items]                      
Number of reportable operating segments | Segment                 1    
Net sales $ 25,624 $ 22,654 $ 21,126 $ 22,365 $ 22,301 $ 17,323 $ 22,798 $ 27,617 $ 91,769 $ 90,039 $ 135,169
Customer Concentration Risk [Member] | Net Sales [Member]                      
Segment Reporting Information [Line Items]                      
Number of customers | Customer 1       0       1 0 0
Concentration risk percentage                 11.00%    
Customer Concentration Risk [Member] | Net Sales [Member] | Minimum [Member]                      
Segment Reporting Information [Line Items]                      
Concentration risk percentage                   10.00% 10.00%
SUDAN [Member]                      
Segment Reporting Information [Line Items]                      
Net sales                 $ 0 $ 0 $ 0
IRAN [Member]                      
Segment Reporting Information [Line Items]                      
Net sales                 0 0 0
SYRIA [Member]                      
Segment Reporting Information [Line Items]                      
Net sales                 $ 0 $ 0 $ 0