v3.4.0.3
Wireless Licenses, Goodwill and Other Intangible Assets - Additional Information (Detail) - USD ($)
$ in Millions
3 Months Ended
Mar. 31, 2016
Dec. 31, 2015
Indefinite-lived Intangible Assets [Line Items]    
Assets held for sale $ 720 $ 792
Wireless Licenses    
Indefinite-lived Intangible Assets [Line Items]    
Assets held for sale 300  
Acquisitions 3  
Wireless licenses under development $ 10,400  
Average remaining renewal period of wireless license portfolio (in years) 5 years 7 months 6 days  
Advanced Wireless Services Spectrum Licenses    
Indefinite-lived Intangible Assets [Line Items]    
Acquisitions $ 400