Guarantor and Non-Guarantor Subsidiaries Financial Information - Consolidating Statement of Operations (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended																12 Months Ended
	Sep. 30, 2014		Jun. 30, 2014		Mar. 31, 2014		Dec. 31, 2013		Sep. 30, 2013		Jun. 30, 2013		Mar. 31, 2013		Dec. 31, 2012		Sep. 30, 2014		Sep. 30, 2013		Sep. 30, 2012
Condensed Income Statements Captions [Line Items]
Revenues	$ 771	[1]	$ 788	[1]	$ 653	[1]	$ 815	[1]	$ 764	[1]	$ 663	[1]	$ 675	[1]	$ 769	[1]	$ 3,027		$ 2,871		$ 2,780
Costs and expenses:
Cost of revenue	(393)	[1]	(417)	[1]	(319)	[1]	(441)	[1]	(389)	[1]	(369)	[1]	(327)	[1]	(407)	[1]	(1,570)		(1,492)		(1,455)
Selling, general and administrative expenses	(287)	[1],[2]	(319)	[1],[2]	(273)	[1],[2]	(293)	[1],[2]	(352)	[1],[3]	(238)	[1],[3]	(244)	[1],[3]	(263)	[1],[3]	(1,172)	[4]	(1,097)	[4]	(1,023)	[4]
Amortization expense	(67)	[1]	(67)	[1]	(66)	[1]	(66)	[1]	(64)	[1]	(48)	[1]	(47)	[1]	(48)	[1]	(266)		(207)		(193)
Total costs and expenses	(747)	[1]	(803)	[1]	(658)	[1]	(800)	[1]	(805)	[1]	(655)	[1]	(618)	[1]	(718)	[1]	(3,008)		(2,796)		(2,671)
Operating income	24	[1]	(15)	[1]	(5)	[1]	15	[1]	(41)	[1]	8	[1]	57	[1]	51	[1]	19		75		109
Loss on extinguishment of debt			(141)	[1]							(2)	[1]			(83)	[1]	(141)		(85)
Interest income (expense), net	(46)	[1]	(48)	[1]	(54)	[1]	(55)	[1]	(54)	[1]	(47)	[1]	(49)	[1]	(53)	[1]	(203)		(203)		(225)
Other income (expense)	(1)	[1]	4	[1]	(3)	[1]	(4)	[1]	(1)	[1]	(2)	[1]	(4)	[1]	(5)	[1]	(4)		(12)		8
Loss before income taxes	(23)	[1]	(200)	[1]	(62)	[1]	(44)	[1]	(96)	[1]	(43)	[1]	4	[1]	(90)	[1]	(329)		(225)		(108)
Income tax benefit (expense)	(1)	[1]	16	[1]	3	[1]	8	[1]	39	[1]	(19)	[1]			11	[1]	26		31		(1)
Net loss	(24)	[1]	(184)	[1]	(59)	[1]	(36)	[1]	(57)	[1]	(62)	[1]	4	[1]	(79)	[1]	(303)		(194)		(109)
Less: Income attributable to noncontrolling interest	(2)	[1]	(1)	[1]	(1)	[1]	(1)	[1]			(1)	[1]	(2)	[1]	(1)	[1]	(5)		(4)		(3)
Net loss attributable to Warner Music Group Corp.	(26)	[1]	(185)	[1]	(60)	[1]	(37)	[1]	(57)	[1]	(63)	[1]	2	[1]	(80)	[1]	(308)		(198)		(112)
Eliminations
Condensed Income Statements Captions [Line Items]
Revenues																	(275)		(277)		(246)
Costs and expenses:
Cost of revenue																	158		195		178
Selling, general and administrative expenses																	117		82		68
Total costs and expenses																	275		277		246
Equity gains (losses) from consolidated subsidiaries																	(33)		50		(91)
Loss before income taxes																	(33)		50		(91)
Income tax benefit (expense)																	(17)		(34)		7
Net loss																	(50)		16		(84)
Net loss attributable to Warner Music Group Corp.																	(50)		16		(84)
Eliminations
Costs and expenses:
Equity gains (losses) from consolidated subsidiaries																	594		374		202
Loss before income taxes																	594		374		202
Net loss																	594		374		202
Net loss attributable to Warner Music Group Corp.																	594		374		202
WMG Acquisition Corp. (issuer)
Costs and expenses:
Selling, general and administrative expenses																	(1)		(1)
Total costs and expenses																	(1)		(1)
Operating income																	(1)		(1)
Loss on extinguishment of debt																	(141)		(85)
Interest income (expense), net																	(102)		(154)		(196)
Equity gains (losses) from consolidated subsidiaries																	(80)		(10)		99
Other income (expense)																	12		43		8
Loss before income taxes																	(312)		(207)		(89)
Income tax benefit (expense)																	26		31		(1)
Net loss																	(286)		(176)		(90)
Net loss attributable to Warner Music Group Corp.																	(286)		(176)		(90)
Guarantor Subsidiaries
Condensed Income Statements Captions [Line Items]
Revenues																	1,498		1,637		1,489
Costs and expenses:
Cost of revenue																	(639)		(782)		(706)
Selling, general and administrative expenses																	(633)		(578)		(546)
Amortization expense																	(120)		(118)		(116)
Total costs and expenses																	(1,392)		(1,478)		(1,368)
Operating income																	106		159		121
Interest income (expense), net																	9		6		6
Equity gains (losses) from consolidated subsidiaries																	113		(40)		(8)
Other income (expense)																	(18)		(29)
Loss before income taxes																	210		96		119
Income tax benefit (expense)																	(9)				(5)
Net loss																	201		96		114
Less: Income attributable to noncontrolling interest																	(1)		(2)		(1)
Net loss attributable to Warner Music Group Corp.																	200		94		113
Non-Guarantor Subsidiaries
Condensed Income Statements Captions [Line Items]
Revenues																	1,804		1,511		1,537
Costs and expenses:
Cost of revenue																	(1,089)		(905)		(927)
Selling, general and administrative expenses																	(655)		(600)		(545)
Amortization expense																	(146)		(89)		(77)
Total costs and expenses																	(1,890)		(1,594)		(1,549)
Operating income																	(86)		(83)		(12)
Interest income (expense), net																	(88)		(33)		(13)
Other income (expense)																	2		(26)
Loss before income taxes																	(172)		(142)		(25)
Income tax benefit (expense)																	26		34		(2)
Net loss																	(146)		(108)		(27)
Less: Income attributable to noncontrolling interest																	(4)		(2)		(2)
Net loss attributable to Warner Music Group Corp.																	(150)		(110)		(29)
WMG Acquisition Corp. Consolidated
Condensed Income Statements Captions [Line Items]
Revenues																	3,027		2,871		2,780
Costs and expenses:
Cost of revenue																	(1,570)		(1,492)		(1,455)
Selling, general and administrative expenses																	(1,172)		(1,097)		(1,023)
Amortization expense																	(266)		(207)		(193)
Total costs and expenses																	(3,008)		(2,796)		(2,671)
Operating income																	19		75		109
Loss on extinguishment of debt																	(141)		(85)
Interest income (expense), net																	(181)		(181)		(203)
Other income (expense)																	(4)		(12)		8
Loss before income taxes																	(307)		(203)		(86)
Income tax benefit (expense)																	26		31		(1)
Net loss																	(281)		(172)		(87)
Less: Income attributable to noncontrolling interest																	(5)		(4)		(3)
Net loss attributable to Warner Music Group Corp.																	(286)		(176)		(90)
WMG Holdings Corp. (issuer)
Costs and expenses:
Interest income (expense), net																	(22)		(22)		(22)
Equity gains (losses) from consolidated subsidiaries																	(286)		(176)		(90)
Loss before income taxes																	(308)		(198)		(112)
Net loss																	(308)		(198)		(112)
Net loss attributable to Warner Music Group Corp.																	(308)		(198)		(112)
Warner Music Group Corp.
Costs and expenses:
Equity gains (losses) from consolidated subsidiaries																	(308)		(198)		(112)
Loss before income taxes																	(308)		(198)		(112)
Net loss																	(308)		(198)		(112)
Net loss attributable to Warner Music Group Corp.																	$ (308)		$ (198)		$ (112)

[1] Quarterly operating results can be disproportionately affected by a particularly strong or weak quarter. Therefore, these quarterly operating results are not necessarily indicative of the results that may be expected for the full fiscal year.

[2] (a) Includes depreciation expense of: $(16) $(14) $(13) $(12)

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

[4] (a) Includes depreciation expense of: $(55) $(51) $(51)