Consolidated Statements of Equity (Unaudited) - USD ($) $ in Millions	Total	Class A Common Stock	Class B Common Stock	Total Warner Music Group Corp. Equity	Common Stock Class A Common Stock	Common Stock Class B Common Stock	Additional Paid-in Capital	Accumulated Deficit	Accumulated Other Comprehensive Loss	Non-controlling Interest
Beginning balance (in shares) at Sep. 30, 2020					88,578,361	421,450,000
Beginning balance at Sep. 30, 2020	$ (45)			$ (63)	$ 0	$ 1	$ 1,907	$ (1,749)	$ (222)	$ 18
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	99			98				98		1
Other comprehensive income (loss), net of tax	37			37					37
Dividends ($0.15 per Class A and B share)	(62)			(62)				(62)
Stock-based compensation expense	6			6			6
Distribution to noncontrolling interest holders	(2)									(2)
Exchange of Class B shares for Class A shares (in shares)					18,265,183	18,265,186
Shares issued under the Plan (in shares)					4,321,259
Shares issued under Omnibus Incentive Plan (in shares)					2,553
Ending balance (in shares) at Dec. 31, 2020					111,167,356	403,184,814
Ending balance at Dec. 31, 2020	33			16	$ 0	$ 1	1,913	(1,713)	(185)	17
Beginning balance (in shares) at Sep. 30, 2021		122,414,827	391,970,996		122,414,827	391,970,996
Beginning balance at Sep. 30, 2021	46			31	$ 0	$ 1	1,942	(1,710)	(202)	15
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	188			187				187		1
Other comprehensive income (loss), net of tax	(18)			(18)					(18)
Dividends ($0.15 per Class A and B share)	(78)			(78)				(78)
Stock-based compensation expense	31			31			31
Distribution to noncontrolling interest holders	(1)									(1)
Conversion of Class B shares (in shares)			4,160,745		4,670,910	4,670,910
Shares issued under Omnibus Incentive Plan (in shares)					151,046
Other	4									4
Ending balance (in shares) at Dec. 31, 2021		127,236,783	387,300,086		127,236,783	387,300,086
Ending balance at Dec. 31, 2021	$ 172			$ 153	$ 0	$ 1	$ 1,973	$ (1,601)	$ (220)	$ 19