v3.8.0.1
Organization and Summary of Significant Accounting Policies Organization and Summary of Significant Accounting Policies - Concentration of Credit Risk (Detail)
12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Revenue, Percentage 100.00% 100.00% 100.00%
Customer [Member]      
Concentration Risk, Percentage 10.00%    
Entity Wide Accounts Receivable By Major Customer Percentage 13.00% 22.00%  
Customer B [Member]      
Entity Wide Accounts Receivable By Major Customer Percentage 19.00% 18.00%  
Byram [Member]      
Concentration Risk, Percentage 14.00% 17.00% 18.00%
Edgepark [Member]      
Concentration Risk, Percentage 17.00% 16.00% 16.00%
Individual Country [Member] | Maximum [Member]      
Revenue, Percentage 10.00% 10.00% 10.00%