Guarantor and Non-Guarantor Subsidiaries Financial Information - Consolidating Statement of Comprehensive Income (Detail) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2014
Condensed Statement Of Income Captions [Line Items]
Net (loss) income	$ 30	$ (88)	$ (303)
Other comprehensive income (loss), net of tax:
Foreign currency adjustment	(44)	(59)	(41)
Minimum pension liability	(7)		(6)
Other comprehensive income (loss), net of tax	(51)	(59)	(47)
Total comprehensive (loss) income	(21)	(147)	(350)
Less: Income attributable to noncontrolling interest	(5)	(3)	(5)
Comprehensive (loss) income attributable to Warner Music Group Corp.	(26)	(150)	(355)
Eliminations
Condensed Statement Of Income Captions [Line Items]
Net (loss) income	(216)	60	(50)
Other comprehensive income (loss), net of tax:
Foreign currency adjustment	44	59	41
Minimum pension liability	7		6
Deferred (loss) gain on derivative financial instruments	1
Other comprehensive income (loss), net of tax	52	59	47
Total comprehensive (loss) income	(164)	119	(3)
Comprehensive (loss) income attributable to Warner Music Group Corp.	(164)	119	(3)
Eliminations
Condensed Statement Of Income Captions [Line Items]
Net (loss) income	(78)	160	594
Other comprehensive income (loss), net of tax:
Foreign currency adjustment	88	118	82
Minimum pension liability	14		12
Other comprehensive income (loss), net of tax	102	118	94
Total comprehensive (loss) income	24	278	688
Comprehensive (loss) income attributable to Warner Music Group Corp.	24	278	688
WMG Acquisition Corp. | Reportable Legal Entities
Condensed Statement Of Income Captions [Line Items]
Net (loss) income	53	(69)	(286)
Other comprehensive income (loss), net of tax:
Foreign currency adjustment	(44)	(59)	(41)
Minimum pension liability	(7)		(6)
Other comprehensive income (loss), net of tax	(51)	(59)	(47)
Total comprehensive (loss) income	2	(128)	(333)
Comprehensive (loss) income attributable to Warner Music Group Corp.	2	(128)	(333)
Guarantor Subsidiaries | Reportable Legal Entities
Condensed Statement Of Income Captions [Line Items]
Net (loss) income	167	(42)	201
Other comprehensive income (loss), net of tax:
Deferred (loss) gain on derivative financial instruments	(1)
Other comprehensive income (loss), net of tax	(1)
Total comprehensive (loss) income	166	(42)	201
Less: Income attributable to noncontrolling interest	(1)	(1)	(1)
Comprehensive (loss) income attributable to Warner Music Group Corp.	165	(43)	200
Non-Guarantor Subsidiaries | Reportable Legal Entities
Condensed Statement Of Income Captions [Line Items]
Net (loss) income	54	(15)	(146)
Other comprehensive income (loss), net of tax:
Foreign currency adjustment	(44)	(59)	(41)
Minimum pension liability	(7)		(6)
Other comprehensive income (loss), net of tax	(51)	(59)	(47)
Total comprehensive (loss) income	3	(74)	(193)
Less: Income attributable to noncontrolling interest	(4)	(2)	(4)
Comprehensive (loss) income attributable to Warner Music Group Corp.	(1)	(76)	(197)
WMG Acquisition Corp. Consolidated | Reportable Legal Entities
Condensed Statement Of Income Captions [Line Items]
Net (loss) income	58	(66)	(281)
Other comprehensive income (loss), net of tax:
Foreign currency adjustment	(44)	(59)	(41)
Minimum pension liability	(7)		(6)
Other comprehensive income (loss), net of tax	(51)	(59)	(47)
Total comprehensive (loss) income	7	(125)	(328)
Less: Income attributable to noncontrolling interest	(5)	(3)	(5)
Comprehensive (loss) income attributable to Warner Music Group Corp.	2	(128)	(333)
WMG Holdings Corp. | Reportable Legal Entities
Condensed Statement Of Income Captions [Line Items]
Net (loss) income	25	(91)	(308)
Other comprehensive income (loss), net of tax:
Foreign currency adjustment	(44)	(59)	(41)
Minimum pension liability	(7)		(6)
Other comprehensive income (loss), net of tax	(51)	(59)	(47)
Total comprehensive (loss) income	(26)	(150)	(355)
Comprehensive (loss) income attributable to Warner Music Group Corp.	(26)	(150)	(355)
Warner Music Group Corp. | Reportable Legal Entities
Condensed Statement Of Income Captions [Line Items]
Net (loss) income	25	(91)	(308)
Other comprehensive income (loss), net of tax:
Foreign currency adjustment	(44)	(59)	(41)
Minimum pension liability	(7)		(6)
Other comprehensive income (loss), net of tax	(51)	(59)	(47)
Total comprehensive (loss) income	(26)	(150)	(355)
Comprehensive (loss) income attributable to Warner Music Group Corp.	$ (26)	$ (150)	$ (355)