Goodwill and Intangible Assets - Schedule of Intangible Assets (Detail) - USD ($) $ in Millions	6 Months Ended
	Mar. 31, 2017	Sep. 30, 2016
Finite Lived And Indefinite Lived Intangible Assets [Line Items]
Total gross intangible asset subject to amortization	$ 3,249	$ 3,322
Accumulated amortization	(1,193)	(1,121)
Total net intangible assets subject to amortization	2,056	2,201
Intangible assets not subject to amortization	116	116
Total net intangible assets	2,172	2,317
Trademarks and tradenames
Finite Lived And Indefinite Lived Intangible Assets [Line Items]
Intangible assets not subject to amortization	$ 116	116
Recorded music catalog
Finite Lived And Indefinite Lived Intangible Assets [Line Items]
Intangible assets, Useful Life	10 years
Total gross intangible asset subject to amortization	$ 893	923
Music publishing copyrights
Finite Lived And Indefinite Lived Intangible Assets [Line Items]
Intangible assets, Useful Life	27 years
Total gross intangible asset subject to amortization	$ 1,484	1,504
Artist and songwriter contracts
Finite Lived And Indefinite Lived Intangible Assets [Line Items]
Intangible assets, Useful Life	13 years
Total gross intangible asset subject to amortization	$ 860	883
Trademarks
Finite Lived And Indefinite Lived Intangible Assets [Line Items]
Intangible assets, Useful Life	7 years
Total gross intangible asset subject to amortization	$ 7	7
Other Intangible Assets
Finite Lived And Indefinite Lived Intangible Assets [Line Items]
Intangible assets, Useful Life	8 years
Total gross intangible asset subject to amortization	$ 5	$ 5