Inventory (Details) - USD ($) $ in Millions	Dec. 31, 2018	Sep. 30, 2018
Film inventory:
Released, net of amortization	$ 575	$ 454
Completed, not yet released	31	11
In process and other	653	713
Television productions:
Released, net of amortization	4	6
In process and other	224	201
Original programming:
Released, net of amortization	1,032	1,124
In process and other	875	757
Acquired program rights, net of amortization	1,301	1,411
Home entertainment inventory	64	67
Total inventory, net	4,759	4,744
Less current portion	829	896
Noncurrent portion	3,930	3,848
Film Inventory
Inventory Net [Line Items]
Total Inventory Net Of Amortization	1,259	1,178
Television Productions
Inventory Net [Line Items]
Total Inventory Net Of Amortization	228	207
Original Programming
Inventory Net [Line Items]
Total Inventory Net Of Amortization	$ 1,907	$ 1,881