Annual report pursuant to Section 13 and 15(d)

Concentrations (Details)

v3.8.0.1
Concentrations (Details) - Customer Concentration Risk
12 Months Ended
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2014
Sales Revenue, Segment      
Concentration Risk [Line Items]      
Revenue percentage generated by major customer 22.00% 23.00% 24.00%
Sales Revenue, Segment | Maritime & Land Connectivity      
Concentration Risk [Line Items]      
Revenue percentage generated by major customer 83.00% 85.00% 83.00%
Accounts Receivable | Maritime & Land Connectivity      
Concentration Risk [Line Items]      
Revenue percentage generated by major customer 12.00% 6.00%