Major Customer (Details) (Operating Revenues [Member], Sprint Nextel [Member])	12 Months Ended
	Dec. 31, 2013 Customer	Dec. 31, 2012	Dec. 31, 2011
Concentration Risk [Line Items]
Number of Major Customer	1
Concentration risk (in hundredths)	59.00%	59.00%	57.00%
Maximum [Member]
Concentration Risk [Line Items]
Concentration risk (in hundredths)	1.50%	1.50%	1.50%