Consolidated Statements of Operations - USD ($) $ in Millions	3 Months Ended																12 Months Ended
	Sep. 30, 2016		Jun. 30, 2016		Mar. 31, 2016		Dec. 31, 2015		Sep. 30, 2015		Jun. 30, 2015		Mar. 31, 2015		Dec. 31, 2014		Sep. 30, 2016		Sep. 30, 2015		Sep. 30, 2014
Income Statement [Abstract]
Revenues	$ 841		$ 811		$ 745		$ 849		$ 750		$ 710		$ 677		$ 829		$ 3,246		$ 2,966		$ 3,027
Costs and expenses:
Cost of revenue	(436)		(448)		(374)		(449)		(375)		(373)		(318)		(445)		(1,707)		(1,511)		(1,570)
Selling, general and administrative expenses	(295)	[1]	(255)	[1]	(256)	[1]	(276)	[1]	(274)	[2]	(251)	[2]	(252)	[2]	(296)	[2]	(1,082)	[3]	(1,073)	[3]	(1,172)	[3]
Amortization expense	(55)		(63)		(63)		(62)		(64)		(63)		(63)		(65)		(243)		(255)		(266)
Total costs and expenses	(786)		(766)		(693)		(787)		(713)		(687)		(633)		(806)		(3,032)		(2,839)		(3,008)
Operating income	55		45		52		62		37		23		44		23		214		127		19
Loss on extinguishment of debt	(14)				(4)												(18)				(141)
Interest expense, net	(42)		(43)		(43)		(45)		(45)		(45)		(45)		(46)		(173)		(181)		(203)
Other income (expense)	(7)		(5)		22		8		(9)		(17)		14		(9)		18		(21)		(4)
Income (loss) before income taxes	(8)		(3)		27		25		(17)		(39)		13		(32)		41		(75)		(329)
Income tax (expense) benefit	5		(4)		(15)		3		(6)		(4)		6		(9)		(11)		(13)		26
Net income (loss)																	30		(88)		(303)
Less: Income attributable to noncontrolling interest	(1)		(2)		(1)		(1)				(1)		(1)		(1)		(5)		(3)		(5)
Net income (loss) attributable to Warner Music Group Corp.	$ (4)		$ (9)		$ 11		$ 27		$ (23)		$ (44)		$ 18		$ (42)		$ 25		$ (91)		$ (308)

[1] (a) Includes depreciation expense of: $(13) $(12) $(12) $(13)

[2] (a) Includes depreciation expense of: $(12) $(14) $(14) $(14)

[3] (a) Includes depreciation expense of: $(50) $(54) $(55)