XML 66 R52.htm IDEA: XBRL DOCUMENT v3.8.0.1
Leases - Additional Information (Detail) - USD ($)
$ in Thousands
1 Months Ended 3 Months Ended 9 Months Ended
Jun. 30, 2018
Sep. 30, 2017
Sep. 30, 2016
Sep. 30, 2017
Sep. 30, 2016
Dec. 31, 2016
Leases [Line Items]            
Amortization of deferred airborne lease incentives   $ 10,121 $ 7,765 $ 28,099 $ 20,650  
Deferred airborne lease incentives included in current liabilities   39,071   39,071   $ 36,277
Deferred airborne lease incentives included in non-current liabilities   121,588   121,588   135,879
Revenue share expense, net of amortization of deferred airborne lease incentives   7,700 10,100 26,900 32,300  
Property and equipment, gross   976,707   976,707   816,989
Present value of net minimum lease payments   3,626   3,626    
Present value of net minimum lease payments, current portion   2,149   2,149   2,799
Present value of net minimum lease payments, non-current portion   1,500   1,500    
Scenario, Forecast [Member]            
Leases [Line Items]            
Contingent annual cash rebate $ 1,800          
Leased Computer Equipment [Member]            
Leases [Line Items]            
Property and equipment, gross   5,100   5,100   3,900
Leased Network Equipment [Member]            
Leases [Line Items]            
Property and equipment, gross   7,500   7,500   $ 7,500
Certain Facilities and Equipment [Member]            
Leases [Line Items]            
Rental expense   3,000 3,000 9,000 8,900  
Cell Site Leases [Member]            
Leases [Line Items]            
Rental expense   $ 2,300 $ 2,300 $ 7,000 $ 7,000  
Minimum [Member] | Computer Equipment [Member]            
Leases [Line Items]            
Annual interest rate imputed       8.00%    
Maximum [Member] | Computer Equipment [Member]            
Leases [Line Items]            
Annual interest rate imputed       14.00%