Income Taxes (Narrative) (Details) (USD $)
 12 Months Ended 0 Months Ended
Dec. 31, 2014
Dec. 31, 2013
Dec. 31, 2012
Dec. 31, 2010
Jan. 02, 2014
Dec. 31, 2011
Dec. 31, 2009
Unrecorded Deferred Tax Liability on Unrealized Foreign Currency Gain   $ 41,400,000          
Deferred Tax Assets, Valuation Allowance 4,868,504,000 4,335,913,000          
Deferred Tax Assets, Gross 5,140,998,000 4,637,718,000          
Provision in deferred tax liability 54,386,000 54,386,000          
Deferred tax liability 280,093,000 258,410,000          
Net operating loss carryforwards   10,800,000,000          
Taxable income before net operating loss deduction   30.00%          
Unrecognized tax benefits that reduce future effective tax rate   1,800,000       2,100,000 4,800,000
Change in Future Unrecognized Tax Benefits 4,800,000            
Interest and penalties   200,000 200,000 300,000      
Unrecognized Tax Benefits Due to Change in Facts   26,500,000          
Unrecognized tax benefit interest and penalties expired     2,700,000        
Accrued interest and penalties   2,400,000 2,300,000        
Deferred Tax Assets, Valuation Allowance, Current 281,500,000            
Deferred Tax Assets, Valuation Allowance, Noncurrent 4,600,000,000            
Valuation Allowance, Deferred Tax Asset, Change in Amount 532,600,000            
Nextel Mexico [Member]              
Net operating loss carryforwards   764,000,000          
U.S. Operations [Member]              
Net operating loss carryforwards   210,300,000          
Nextel Brazil [Member]              
Net operating loss carryforwards   816,400,000          
Domestic, State, And Local Jurisdiction [Member]              
Net operating loss carryforwards   1,300,000,000          
MEXICO              
Revised Income Tax Rate         30.00%    
ARGENTINA              
Deferred Tax Assets, Valuation Allowance 49,100,000 0          
Brazil [Member]              
Unrecorded Deferred Tax Liability on Unrealized Foreign Currency Gain 36,000,000            
Deferred Tax Assets, Valuation Allowance 584,100,000 419,100,000          
Luxembourg [Member]              
Deferred Tax Assets, Valuation Allowance 3,169,200,000 3,131,400,000          
Spain [Member]              
Deferred Tax Assets, Valuation Allowance 267,600,000 230,900,000          
Net operating loss carryforwards   844,000,000          
Net operating loss carryforwards, expiration period   18 years          
Netherlands [Member]              
Net operating loss carryforwards   $ 300,000          
Net operating loss carryforwards, expiration period   9 years