Goodwill and Intangible Assets (Schedule of Change in Goodwill) (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018
Goodwill [Roll Forward]
Balance, beginning of period	$ 66,154	$ 36,780
Goodwill	279	29,925
Dispositions	(12)	(13)
Adjustments	1,379	(21)
Foreign currency translation	925	(517)
Balance, end of period	68,725	66,154
NBCUniversal Media LLC [Member]
Goodwill [Roll Forward]
Balance, beginning of period	24,118	23,989
Goodwill	176	36
Dispositions	0	(8)
Adjustments	(104)	(21)
Foreign currency translation	50	122
Balance, end of period	24,240	24,118
Operating Segments [Member] \| Cable Communications [Member]
Goodwill [Roll Forward]
Balance, beginning of period	12,784	12,784
Goodwill	86	0
Dispositions	0	0
Adjustments	2,166	0
Foreign currency translation	38	0
Balance, end of period	15,074	12,784
Operating Segments [Member] \| Cable Networks [Member]
Goodwill [Roll Forward]
Balance, beginning of period	13,407	13,427
Goodwill	162	0
Dispositions	0	0
Adjustments	490	(13)
Foreign currency translation	8	(7)
Balance, end of period	14,067	13,407
Operating Segments [Member] \| Cable Networks [Member] \| NBCUniversal Media LLC [Member]
Goodwill [Roll Forward]
Balance, beginning of period	13,407	13,427
Goodwill	162	0
Dispositions	0	0
Adjustments	(105)	(13)
Foreign currency translation	(2)	(7)
Balance, end of period	13,462	13,407
Operating Segments [Member] \| Broadcast Television [Member]
Goodwill [Roll Forward]
Balance, beginning of period	843	806
Goodwill	14	36
Dispositions	0	0
Adjustments	199	1
Foreign currency translation	3	0
Balance, end of period	1,059	843
Operating Segments [Member] \| Broadcast Television [Member] \| NBCUniversal Media LLC [Member]
Goodwill [Roll Forward]
Balance, beginning of period	843	806
Goodwill	14	36
Dispositions	0	0
Adjustments	0	1
Foreign currency translation	0	0
Balance, end of period	857	843
Operating Segments [Member] \| Filmed Entertainment [Member]
Goodwill [Roll Forward]
Balance, beginning of period	3,184	3,212
Goodwill	0	0
Dispositions	0	(8)
Adjustments	138	(9)
Foreign currency translation	(1)	(11)
Balance, end of period	3,321	3,184
Operating Segments [Member] \| Filmed Entertainment [Member] \| NBCUniversal Media LLC [Member]
Goodwill [Roll Forward]
Balance, beginning of period	3,184	3,212
Goodwill	0	0
Dispositions	0	(8)
Adjustments	1	(9)
Foreign currency translation	(3)	(11)
Balance, end of period	3,182	3,184
Operating Segments [Member] \| Theme Parks [Member]
Goodwill [Roll Forward]
Balance, beginning of period	6,684	6,544
Goodwill	0	0
Dispositions	0	0
Adjustments	0	0
Foreign currency translation	55	140
Balance, end of period	6,739	6,684
Operating Segments [Member] \| Theme Parks [Member] \| NBCUniversal Media LLC [Member]
Goodwill [Roll Forward]
Balance, beginning of period	6,684	6,544
Goodwill	0	0
Dispositions	0	0
Adjustments	0	0
Foreign currency translation	55	140
Balance, end of period	6,739	6,684
Operating Segments [Member] \| Sky Limited [Member]
Goodwill [Roll Forward]
Balance, beginning of period	29,250	0
Goodwill	17	29,889
Dispositions	(12)	0
Adjustments	(1,616)	0
Foreign currency translation	822	(639)
Balance, end of period	28,461	29,250
Corporate, Non-Segment [Member]
Goodwill [Roll Forward]
Balance, beginning of period	2	7
Goodwill	0	0
Dispositions	0	(5)
Adjustments	2	0
Foreign currency translation	0	0
Balance, end of period	$ 4	$ 2

Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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Amount of divestiture of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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