v3.10.0.1
Segment Information (Details) - USD ($)
$ in Millions
 3 Months Ended 12 Months Ended
Dec. 31, 2018
Sep. 30, 2018
Jun. 30, 2018
Mar. 31, 2018
Dec. 31, 2017
Sep. 30, 2017
Jun. 30, 2017
Mar. 31, 2017
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Financial Data by Business Segment                      
Revenue $ 27,846 $ 22,135 $ 21,735 $ 22,791 $ 22,075 $ 21,081 $ 21,286 $ 20,587 $ 94,507 $ 85,029 $ 80,736
Adjusted EBITDA                 30,165 27,956 26,257
Depreciation and Amortization                 11,017 10,130 9,426
Capital Expenditures                 9,774 9,550 9,135
Cash Paid for Intangible Assets                 1,935 1,605 1,552
NBCUniversal Media LLC [Member]                      
Financial Data by Business Segment                      
Revenue                 35,895 32,950 31,398
Adjusted EBITDA                 8,633 8,181 7,163
Depreciation and Amortization                 2,108 2,041 1,805
Capital Expenditures                 1,730 1,502 1,452
Cash Paid for Intangible Assets                 448 295 283
Cable Communications [Member]                      
Financial Data by Business Segment                      
Revenue                 55,143 53,070 50,577
Depreciation and Amortization                   8,006 7,538
Cable Networks [Member]                      
Financial Data by Business Segment                      
Revenue                 11,773 10,497 10,324
Cable Networks [Member] | NBCUniversal Media LLC [Member]                      
Financial Data by Business Segment                      
Revenue                 11,773 10,497 10,324
Broadcast Television [Member]                      
Financial Data by Business Segment                      
Revenue                 11,439 9,563 10,085
Broadcast Television [Member] | NBCUniversal Media LLC [Member]                      
Financial Data by Business Segment                      
Revenue                 11,439 9,563 10,085
Filmed Entertainment [Member]                      
Financial Data by Business Segment                      
Revenue                 7,152 7,595 6,229
Filmed Entertainment [Member] | NBCUniversal Media LLC [Member]                      
Financial Data by Business Segment                      
Revenue                 7,152 7,595 6,229
Theme Parks [Member]                      
Financial Data by Business Segment                      
Revenue                 5,683 5,443 4,946
Theme Parks [Member] | NBCUniversal Media LLC [Member]                      
Financial Data by Business Segment                      
Revenue                 5,683 5,443 4,946
NBCUniversal Segments [Member]                      
Financial Data by Business Segment                      
Revenue                 35,761 32,836 31,276
Adjusted EBITDA                 8,598 8,218 7,138
Depreciation and Amortization                 2,108 2,041 1,805
Capital Expenditures                 1,730 1,502 1,452
Cash Paid for Intangible Assets                 448 295 283
Sky Limited [Member]                      
Financial Data by Business Segment                      
Revenue                 4,587 0 0
Operating Segments [Member] | Cable Communications [Member]                      
Financial Data by Business Segment                      
Revenue                 55,143 53,070 50,577
Adjusted EBITDA                 22,447 21,068 20,014
Depreciation and Amortization                 8,264 8,006 7,538
Capital Expenditures                 7,716 7,952 7,596
Cash Paid for Intangible Assets                 1,282 1,241 1,243
Operating Segments [Member] | Cable Networks [Member]                      
Financial Data by Business Segment                      
Revenue                 11,773 10,497 10,324
Adjusted EBITDA                 4,428 4,053 3,681
Depreciation and Amortization                 738 755 745
Capital Expenditures                 42 33 32
Cash Paid for Intangible Assets                 23 19 20
Operating Segments [Member] | Cable Networks [Member] | NBCUniversal Media LLC [Member]                      
Financial Data by Business Segment                      
Revenue                 11,773 10,497 10,324
Adjusted EBITDA                 4,428 4,053 3,681
Depreciation and Amortization                 738 755 745
Capital Expenditures                 42 33 32
Cash Paid for Intangible Assets                 23 19 20
Operating Segments [Member] | Broadcast Television [Member]                      
Financial Data by Business Segment                      
Revenue                 11,439 9,563 10,085
Adjusted EBITDA                 1,657 1,251 1,293
Depreciation and Amortization                 146 133 125
Capital Expenditures                 204 180 153
Cash Paid for Intangible Assets                 81 22 19
Operating Segments [Member] | Broadcast Television [Member] | NBCUniversal Media LLC [Member]                      
Financial Data by Business Segment                      
Revenue                 11,439 9,563 10,085
Adjusted EBITDA                 1,657 1,251 1,293
Depreciation and Amortization                 146 133 125
Capital Expenditures                 204 180 153
Cash Paid for Intangible Assets                 81 22 19
Operating Segments [Member] | Filmed Entertainment [Member]                      
Financial Data by Business Segment                      
Revenue                 7,152 7,595 6,229
Adjusted EBITDA                 734 1,276 662
Depreciation and Amortization                 145 109 47
Capital Expenditures                 35 58 33
Cash Paid for Intangible Assets                 25 23 16
Operating Segments [Member] | Filmed Entertainment [Member] | NBCUniversal Media LLC [Member]                      
Financial Data by Business Segment                      
Revenue                 7,152 7,595 6,229
Adjusted EBITDA                 734 1,276 662
Depreciation and Amortization                 145 109 47
Capital Expenditures                 35 58 33
Cash Paid for Intangible Assets                 25 23 16
Operating Segments [Member] | Theme Parks [Member]                      
Financial Data by Business Segment                      
Revenue                 5,683 5,443 4,946
Adjusted EBITDA                 2,455 2,384 2,190
Depreciation and Amortization                 660 648 512
Capital Expenditures                 1,143 960 922
Cash Paid for Intangible Assets                 173 78 72
Operating Segments [Member] | Theme Parks [Member] | NBCUniversal Media LLC [Member]                      
Financial Data by Business Segment                      
Revenue                 5,683 5,443 4,946
Adjusted EBITDA                 2,455 2,384 2,190
Depreciation and Amortization                 660 648 512
Capital Expenditures                 1,143 960 922
Cash Paid for Intangible Assets                 173 78 72
Operating Segments [Member] | Sky Limited [Member]                      
Financial Data by Business Segment                      
Revenue                 4,587    
Adjusted EBITDA                 692    
Depreciation and Amortization                 539    
Capital Expenditures                 222    
Cash Paid for Intangible Assets                 137    
Corporate, Non-Segment [Member]                      
Financial Data by Business Segment                      
Revenue                 1,403 1,193 886
Adjusted EBITDA                 (1,545) (1,372) (849)
Depreciation and Amortization                 106 83 83
Capital Expenditures                 106 96 87
Cash Paid for Intangible Assets                 68 69 26
Corporate, Non-Segment [Member] | NBCUniversal Media LLC [Member]                      
Financial Data by Business Segment                      
Revenue                 212 179 157
Adjusted EBITDA                 (645) (779) (674)
Depreciation and Amortization                 419 396 376
Capital Expenditures                 306 271 312
Cash Paid for Intangible Assets                 146 153 156
Corporate, Non-Segment [Member] | NBCUniversal Segments [Member]                      
Financial Data by Business Segment                      
Revenue                 63 45 20
Adjusted EBITDA                 (680) (741) (699)
Depreciation and Amortization                 419 396 376
Capital Expenditures                 306 271 312
Cash Paid for Intangible Assets                 146 153 156
Eliminations [Member]                      
Financial Data by Business Segment                      
Revenue                 (2,387) (2,070) (2,003)
Adjusted EBITDA                 (27) 42 (46)
Depreciation and Amortization                 0 0 0
Capital Expenditures                 0 0 0
Cash Paid for Intangible Assets                 0 0 0
Eliminations [Member] | NBCUniversal Media LLC [Member]                      
Financial Data by Business Segment                      
Revenue                 (364) (327) (343)
Adjusted EBITDA                 4 (4) 11
Depreciation and Amortization                 0 0 0
Capital Expenditures                 0 0 0
Cash Paid for Intangible Assets                 0 0 0
Eliminations [Member] | NBCUniversal Segments [Member]                      
Financial Data by Business Segment                      
Revenue                 (349) (307) (328)
Adjusted EBITDA                 4 (5) 11
Depreciation and Amortization                 0 0 0
Capital Expenditures                 0 0 0
Cash Paid for Intangible Assets                 $ 0 $ 0 $ 0