Acquisitions Changes in Carrying Amount of Goodwill (Detail) - USD ($) $ in Millions		12 Months Ended
		Sep. 30, 2017	Oct. 01, 2016
Goodwill [Roll Forward]
Beginning balance		$ 27,810	$ 27,826
Acquisitions		3,600	2
Dispositions		0	0
Other, net		16	(18)
Ending balance		31,426	27,810
Media Networks
Goodwill [Roll Forward]
Beginning balance		16,345	16,354
Acquisitions		0	1
Dispositions		0	0
Other, net		(20)	(10)
Ending balance		16,325	16,345
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		6,830	6,836
Acquisitions		0	1
Dispositions		0	0
Other, net		(13)	(7)
Ending balance		6,817	6,830
Consumer Products and Interactive
Goodwill [Roll Forward]
Beginning balance		4,344	4,345
Acquisitions		0	0
Dispositions		0	0
Other, net		49	(1)
Ending balance		4,393	4,344
Unallocated
Goodwill [Roll Forward]
Beginning balance	[1]	0	0
Acquisitions	[1]	3,600	0
Dispositions	[1]	0	0
Other, net	[1]	0	0
Ending balance	[1]	$ 3,600	$ 0

[1] Goodwill will be allocated to the segments once the BAMTech purchase price allocation is finalized.