v3.7.0.1
Supplemental Financial Information (Receivables)(Details) - USD ($)
$ in Millions
Mar. 31, 2017
Dec. 31, 2016
Supplemental Financial Information [Line Items]    
Receivables, gross $ 8,111 $ 8,622
Less: Allowance for returns and customer incentives 347 417
Less: Allowance for doubtful accounts 239 250
Receivables, net 7,525 7,955
NBCUniversal Media LLC [Member]    
Supplemental Financial Information [Line Items]    
Receivables, gross 6,647 6,799
Less: Allowance for returns and customer incentives 343 413
Less: Allowance for doubtful accounts 77 84
Receivables, net $ 6,227 $ 6,302