Segment Information (Details) $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2021 USD ($)	Jun. 30, 2020 USD ($)	Jun. 30, 2021 USD ($) segment	Jun. 30, 2020 USD ($)
Segment Reporting Information [Line Items]
Number of reportable segments \| segment			5
Financial Data by Business Segment
Revenue	$ 28,546	$ 23,715	$ 55,751	$ 50,324
Adjusted EBITDA	8,927	7,927	17,339	16,057
Depreciation and Amortization	3,383	3,264	6,745	6,528
Capital Expenditures	2,144	2,076	4,003	3,957
Cash Paid for Intangible Assets	671	601	1,283	1,219
Total Intersegment Eliminations [Member]
Financial Data by Business Segment
Revenue	1,257	1,127	3,010	2,294
Eliminations [Member]
Financial Data by Business Segment
Revenue	(723)	(547)	(1,434)	(1,222)
Adjusted EBITDA	2	11	11	18
Depreciation and Amortization	0	0	0	0
Capital Expenditures	0	0	0	0
Cash Paid for Intangible Assets	0	0	$ 0	0
Cable Communications [Member] \| Operating Segments [Member]
Segment Reporting Information [Line Items]
Number of reportable segments \| segment			1
Financial Data by Business Segment
Revenue	16,002	14,428	$ 31,807	29,346
Adjusted EBITDA	7,073	6,176	13,903	12,252
Depreciation and Amortization	1,950	1,937	3,880	3,883
Capital Expenditures	1,695	1,452	3,065	2,721
Cash Paid for Intangible Assets	337	326	652	682
Cable Communications [Member] \| Total Intersegment Eliminations [Member]
Financial Data by Business Segment
Revenue	47	41	93	82
Media [Member] \| Operating Segments [Member]
Financial Data by Business Segment
Revenue	5,148	4,096	10,184	8,974
Adjusted EBITDA	1,378	1,636	2,851	3,165
Depreciation and Amortization	254	244	501	487
Capital Expenditures	19	29	29	60
Cash Paid for Intangible Assets	42	49	75	87
Media [Member] \| Total Intersegment Eliminations [Member]
Financial Data by Business Segment
Revenue	543	426	1,082	967
Studios [Member] \| Operating Segments [Member]
Financial Data by Business Segment
Revenue	2,224	2,052	4,620	4,461
Adjusted EBITDA	156	323	653	623
Depreciation and Amortization	12	15	25	32
Capital Expenditures	1	2	2	6
Cash Paid for Intangible Assets	5	2	7	3
Studios [Member] \| Total Intersegment Eliminations [Member]
Financial Data by Business Segment
Revenue	589	625	1,678	1,165
Theme Parks [Member] \| Operating Segments [Member]
Financial Data by Business Segment
Revenue	1,095	136	1,714	1,061
Adjusted EBITDA	221	(393)	159	(306)
Depreciation and Amortization	195	191	402	381
Capital Expenditures	100	295	226	591
Cash Paid for Intangible Assets	8	16	15	31
Theme Parks [Member] \| Total Intersegment Eliminations [Member]
Financial Data by Business Segment
Revenue	0	0	1	0
Headquarters and Other [Member] \| Operating Segments [Member]
Financial Data by Business Segment
Revenue	22	11	38	20
Adjusted EBITDA	(186)	(82)	(395)	(303)
Depreciation and Amortization	125	129	241	245
Capital Expenditures	62	54	98	100
Cash Paid for Intangible Assets	30	37	57	78
Headquarters and Other [Member] \| Total Intersegment Eliminations [Member]
Financial Data by Business Segment
Revenue	17	4	$ 29	7
NBCUniversal Segments [Member] \| Operating Segments [Member]
Segment Reporting Information [Line Items]
Number of reportable segments \| segment			3
Financial Data by Business Segment
Revenue	7,955	5,715	$ 14,980	13,444
Adjusted EBITDA	1,553	1,380	3,043	3,069
Depreciation and Amortization	586	579	1,168	1,145
Capital Expenditures	182	380	354	757
Cash Paid for Intangible Assets	86	104	153	199
NBCUniversal Segments [Member] \| Eliminations [Member]
Financial Data by Business Segment
Revenue	(534)	(580)	(1,576)	(1,072)
Adjusted EBITDA	(15)	(104)	(225)	(110)
Depreciation and Amortization	0	0	0	0
Capital Expenditures	0	0	0	0
Cash Paid for Intangible Assets	0	0	$ 0	0
Sky Limited [Member] \| Operating Segments [Member]
Segment Reporting Information [Line Items]
Number of reportable segments \| segment			1
Financial Data by Business Segment
Revenue	5,220	4,079	$ 10,217	8,596
Adjusted EBITDA	560	749	924	1,300
Depreciation and Amortization	826	720	1,640	1,438
Capital Expenditures	184	215	455	412
Cash Paid for Intangible Assets	211	170	412	336
Sky Limited [Member] \| Total Intersegment Eliminations [Member]
Financial Data by Business Segment
Revenue	15	7	23	9
Corporate and Other [Member] \| Operating Segments [Member]
Financial Data by Business Segment
Revenue	92	40	181	160
Adjusted EBITDA	(261)	(389)	(541)	(582)
Depreciation and Amortization	21	28	57	62
Capital Expenditures	83	29	128	67
Cash Paid for Intangible Assets	37	1	65	2
Corporate and Other [Member] \| Total Intersegment Eliminations [Member]
Financial Data by Business Segment
Revenue	$ 47	$ 24	$ 105	$ 64

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