Segment Information - Schedule of Segment Information (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Segment Reporting Information [Line Items]
Revenue	$ 1,058	$ 958	$ 3,351	$ 2,966
Operating income (loss)	58	28	327	201
Amortization of intangible assets	51	56	160	164
Depreciation of property, plant and equipment	15	15	43	41
OIBDA	124	99	530	406
Operating Segments | Recorded Music
Segment Reporting Information [Line Items]
Revenue	913	802	2,887	2,497
Operating income (loss)	85	67	382	276
Amortization of intangible assets	34	39	109	113
Depreciation of property, plant and equipment	12	9	31	26
OIBDA	131	115	522	415
Operating Segments | Music Publishing
Segment Reporting Information [Line Items]
Revenue	147	159	470	476
Operating income (loss)	18	5	67	45
Amortization of intangible assets	17	17	51	51
Depreciation of property, plant and equipment	1	2	4	5
OIBDA	36	24	122	101
Corporate expenses and eliminations
Segment Reporting Information [Line Items]
Revenue	(2)	(3)	(6)	(7)
Operating income (loss)	(45)	(44)	(122)	(120)
Amortization of intangible assets	0	0	0	0
Depreciation of property, plant and equipment	2	4	8	10
OIBDA	$ (43)	$ (40)	$ (114)	$ (110)