Quarterly report pursuant to Section 13 or 15(d)

Tower Sale and Leaseback (Narratives) (Details)

v3.7.0.1
Tower Sale and Leaseback (Narratives) (Details) - Tower Sale [Member]
$ in Millions
1 Months Ended 12 Months Ended
Mar. 31, 2017
USD ($)
Aug. 31, 2016
USD ($)
renewal_option
Dec. 31, 2016
USD ($)
Sale Leaseback Transaction [Line Items]      
Net proceeds from sale of cell sites $ 3.7 $ 90.8  
Number of renewal options | renewal_option   8  
Renewal period, term   5 years  
Annual increase in lease payments, percentage   2.00%  
Decrease in asset retirement obligation     $ (3.4)
Interest rate on the Tower Obligation   7.10%  
Minimum [Member]      
Sale Leaseback Transaction [Line Items]      
Lease term (in years)   10 years  
Maximum [Member]      
Sale Leaseback Transaction [Line Items]      
Lease term (in years)   50 years