v3.10.0.1
Recent Accounting Pronouncements (Effects of Changes in Revenue Recognition - Balance Sheet) (Details) - USD ($)
$ in Millions
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
New Accounting Pronouncements or Change in Accounting Principle [Line Items]        
Total current assets $ 21,848 $ 16,343    
Film and television costs 7,837 7,087    
Other intangible assets, net 38,358 18,133    
Other noncurrent assets, net 5,802 4,354    
Total assets 251,684 187,462    
Total current liabilities 27,603 21,993    
Deferred income taxes 27,589 24,259    
Other noncurrent liabilities 15,329 10,972    
Total equity 72,502 69,459 $ 56,163 $ 53,978
Total liabilities and equity 251,684 187,462    
NBCUniversal Media LLC [Member]        
New Accounting Pronouncements or Change in Accounting Principle [Line Items]        
Total current assets 13,247 11,957    
Film and television costs 7,292 7,082    
Other noncurrent assets, net 1,822 1,804    
Total assets 75,014 71,300    
Total current liabilities 8,224 9,932    
Other noncurrent liabilities 5,177 4,153    
Total equity 46,781 43,041 $ 40,875 $ 34,303
Total liabilities and equity $ 75,014 71,300    
Previous Reported [Member]        
New Accounting Pronouncements or Change in Accounting Principle [Line Items]        
Total current assets   16,060    
Film and television costs   7,076    
Other intangible assets, net   18,779    
Other noncurrent assets, net   3,489    
Total assets   186,949    
Total current liabilities   21,561    
Deferred income taxes   24,256    
Other noncurrent liabilities   10,904    
Total equity   69,449    
Total liabilities and equity   186,949    
Previous Reported [Member] | NBCUniversal Media LLC [Member]        
New Accounting Pronouncements or Change in Accounting Principle [Line Items]        
Total current assets   11,673    
Film and television costs   7,071    
Other noncurrent assets, net   1,872    
Total assets   71,073    
Total current liabilities   9,602    
Other noncurrent liabilities   4,109    
Total equity   43,188    
Total liabilities and equity   71,073    
Effects of Adoption [Member] | Accounting Standards Update 2014-09 [Member]        
New Accounting Pronouncements or Change in Accounting Principle [Line Items]        
Total current assets   283    
Film and television costs   11    
Other intangible assets, net   (646)    
Other noncurrent assets, net   865    
Total assets   513    
Total current liabilities   432    
Deferred income taxes   3    
Other noncurrent liabilities   68    
Total equity   10    
Total liabilities and equity   513    
Effects of Adoption [Member] | Accounting Standards Update 2014-09 [Member] | NBCUniversal Media LLC [Member]        
New Accounting Pronouncements or Change in Accounting Principle [Line Items]        
Total current assets   284    
Film and television costs   11    
Other noncurrent assets, net   (68)    
Total assets   227    
Total current liabilities   330    
Other noncurrent liabilities   44    
Total equity   (147)    
Total liabilities and equity   $ 227