Revenue Recognition - Summary of Disaggregation of Revenue (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2018
Disaggregation of Revenue [Line Items]
Total Revenues	$ 4,463	$ 4,475	$ 4,005
Operating Segments | United States
Disaggregation of Revenue [Line Items]
Total Revenues	1,934	1,956	1,754
Operating Segments | International
Disaggregation of Revenue [Line Items]
Total Revenues	2,533	2,527	2,259
Intersegment eliminations
Disaggregation of Revenue [Line Items]
Total Revenues	(4)	(8)	(8)
Recorded Music | Operating Segments
Disaggregation of Revenue [Line Items]
Total Revenues	3,810	3,840	3,360
Recorded Music | Operating Segments | United States
Disaggregation of Revenue [Line Items]
Total Revenues	1,609	1,656	1,460
Recorded Music | Operating Segments | International
Disaggregation of Revenue [Line Items]
Total Revenues	2,201	2,184	1,900
Recorded Music | Digital | Operating Segments
Disaggregation of Revenue [Line Items]
Total Revenues	2,568	2,343	2,019
Recorded Music | Physical | Operating Segments
Disaggregation of Revenue [Line Items]
Total Revenues	434	559	630
Recorded Music | Total Physical and Digital | Operating Segments
Disaggregation of Revenue [Line Items]
Total Revenues	3,002	2,902	2,649
Recorded Music | Artist services and expanded-rights | Operating Segments
Disaggregation of Revenue [Line Items]
Total Revenues	525	629	389
Recorded Music | Licensing | Operating Segments
Disaggregation of Revenue [Line Items]
Total Revenues	283	309	322
Music Publishing | Operating Segments
Disaggregation of Revenue [Line Items]
Total Revenues	657	643	653
Music Publishing | Operating Segments | United States
Disaggregation of Revenue [Line Items]
Total Revenues	325	300	294
Music Publishing | Operating Segments | International
Disaggregation of Revenue [Line Items]
Total Revenues	332	343	359
Music Publishing | Performance | Operating Segments
Disaggregation of Revenue [Line Items]
Total Revenues	142	183	212
Music Publishing | Digital | Operating Segments
Disaggregation of Revenue [Line Items]
Total Revenues	337	271	237
Music Publishing | Mechanical | Operating Segments
Disaggregation of Revenue [Line Items]
Total Revenues	48	55	72
Music Publishing | Synchronization | Operating Segments
Disaggregation of Revenue [Line Items]
Total Revenues	119	120	119
Music Publishing | Other | Operating Segments
Disaggregation of Revenue [Line Items]
Total Revenues	$ 11	$ 14	$ 13