Acquisitions Changes in Carrying Amount of Goodwill (Detail) - USD ($) $ in Millions		12 Months Ended
		Sep. 29, 2018	Sep. 30, 2017
Goodwill [Roll Forward]
Beginning balance		$ 31,426	$ 27,810
Acquisitions		0	3,600
Dispositions		0	0
Other, net		(157)	16
Ending balance		31,269	31,426
Media Networks
Goodwill [Roll Forward]
Beginning balance		16,325	16,345
Acquisitions		0	0
Dispositions		0	0
Other, net		3,063	(20)
Ending balance		19,388	16,325
Parks and Resorts
Goodwill [Roll Forward]
Beginning balance		291	291
Acquisitions		0	0
Dispositions		0	0
Other, net		0	0
Ending balance		291	291
Studio Entertainment
Goodwill [Roll Forward]
Beginning balance		6,817	6,830
Acquisitions		0	0
Dispositions		0	0
Other, net		347	(13)
Ending balance		7,164	6,817
Consumer Products and Interactive
Goodwill [Roll Forward]
Beginning balance		4,393	4,344
Acquisitions		0	0
Dispositions		0	0
Other, net		33	49
Ending balance		4,426	4,393
Unallocated
Goodwill [Roll Forward]
Beginning balance	[1]	3,600	0
Acquisitions	[1]	0	3,600
Dispositions	[1]	0	0
Other, net	[1]	(3,600)	0
Ending balance	[1]	$ 0	$ 3,600

[1] Other, net primarily represents the allocation of BAMTech goodwill to segments based on the final purchase price allocation and also includes the impact of updates to our initial estimated fair value of intangible assets related to BAMTech.