v3.8.0.1
Summary of significant accounting policies - Segment and geographic information (Details)
$ in Thousands
3 Months Ended 12 Months Ended
Dec. 31, 2017
USD ($)
Sep. 30, 2017
USD ($)
Jun. 30, 2017
USD ($)
Mar. 31, 2017
USD ($)
Dec. 31, 2016
USD ($)
Sep. 30, 2016
USD ($)
Jun. 30, 2016
USD ($)
Mar. 31, 2016
USD ($)
Dec. 31, 2017
USD ($)
segment
Dec. 31, 2016
USD ($)
Dec. 31, 2015
USD ($)
Primary revenue source                      
Number of reportable segments | segment                 1    
Revenue $ 57,348 $ 53,655 $ 49,033 $ 44,333 $ 44,974 $ 40,796 $ 39,075 $ 34,499 $ 204,369 $ 159,344 $ 139,626
DAS                      
Primary revenue source                      
Revenue                 80,552 58,182 46,455
Military                      
Primary revenue source                      
Revenue                 55,129 39,975 19,898
Wholesale-Wi-Fi                      
Primary revenue source                      
Revenue                 31,529 22,221 21,923
Retail                      
Primary revenue source                      
Revenue                 24,926 26,636 31,763
Advertising and other                      
Primary revenue source                      
Revenue                 $ 12,233 $ 12,330 $ 19,587