Guarantor and Non-Guarantor Subsidiaries Financial Information - Consolidating Statement of Cash Flows (Detail) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Mar. 31, 2017	Mar. 31, 2016
Cash flows from operating activities
Net income	$ 20	$ 12	$ 44	$ 40
Adjustments to reconcile net income (loss) income to net cashprovided by operating activities:
Depreciation and amortization			126	150
Unrealized (gains)/losses and remeasurement of foreign denominated loans			(1)	(2)
Deferred income taxes			(12)	(10)
Gain on sale of real estate		(19)		(19)
(Gain)/Loss on extinguishment of debt		4	32	4
Net loss on divestitures and investments			6	3
Non-cash interest expense			5	5
Equity-based compensation expense			17	4
Changes in operating assets and liabilities:
Accounts receivable			(41)	25
Inventories			3	(1)
Royalty advances			1	(21)
Accounts payable and accrued liabilities			(43)	(41)
Royalty payables			75	35
Accrued interest			7	(5)
Deferred revenue			(4)	2
Other balance sheet changes			11	3
Net cash (used in) provided by operating activities			226	172
Cash flows from investing activities
Acquisition of music publishing rights, net			(6)	(12)
Capital expenditures			(18)	(23)
Investments and acquisitions of businesses, net			(6)	(8)
Divestitures, net			18	6
Proceeds from the sale of real estate				42
Net cash (used in) provided by investing activities			(12)	5
Cash flows from financing activities
Repayment of Acquisition Corp. Senior Term Loan Facility				(6)
Proceeds from issuance of Acquisition Corp. Senior Term Loan Facility			22
Call premiums paid on early redemption of debt			(27)	(3)
Deferred financing costs paid			(12)
Distribution to noncontrolling interest holder			(1)	(3)
Repayment of capital lease obligations				(14)
Dividends paid			(54)
Net cash (used in) provided by financing activities			(93)	(100)
Effect of exchange rate changes on cash and equivalents			(4)	(7)
Net increase in cash and equivalents			117	70
Cash and equivalents at beginning of period			359	246
Cash and equivalents at end of period	476	316	476	316
4.125% Senior Secured Notes
Cash flows from financing activities
Proceeds from issuance of Acquisition Corp			380
4.875% Senior Secured Notes
Cash flows from financing activities
Proceeds from issuance of Acquisition Corp			250
6.00% Senior Secured Notes
Cash flows from financing activities
Repayment of Senior Secured Notes			(450)
6.25% Senior Secured Notes
Cash flows from financing activities
Repayment of Senior Secured Notes			(173)
5.625% Senior Secured Notes
Cash flows from financing activities
Repayment of Senior Secured Notes			(28)
13.75% Senior Notes
Cash flows from financing activities
Repayment of Senior Notes				(50)
6.75% Senior Notes
Cash flows from financing activities
Repayment of Senior Notes				(24)
Reportable Legal Entities | WMG Acquisition Corp.
Cash flows from operating activities
Net income	19	21	41	53
Adjustments to reconcile net income (loss) income to net cashprovided by operating activities:
Unrealized (gains)/losses and remeasurement of foreign denominated loans			(11)	(1)
Deferred income taxes			2
(Gain)/Loss on extinguishment of debt			32	(1)
Non-cash interest expense			5	5
Equity (gains) losses, including distributions			(132)	(105)
Changes in operating assets and liabilities:
Accrued interest			7	(1)
Other balance sheet changes			7
Net cash (used in) provided by operating activities			(49)	(50)
Cash flows from investing activities
Advances to issuer			87	163
Net cash (used in) provided by investing activities			87	163
Cash flows from financing activities
Dividend by Acquisition Corp. to Holdings Corp.				(83)
Repayment of Acquisition Corp. Senior Term Loan Facility				(6)
Proceeds from issuance of Acquisition Corp. Senior Term Loan Facility			22
Call premiums paid on early redemption of debt			(27)
Deferred financing costs paid			(12)
Net cash (used in) provided by financing activities			(38)	(113)
Reportable Legal Entities | Guarantor Subsidiaries
Cash flows from operating activities
Net income	49	15	144	88
Adjustments to reconcile net income (loss) income to net cashprovided by operating activities:
Depreciation and amortization			70	80
Unrealized (gains)/losses and remeasurement of foreign denominated loans			(3)	(1)
Deferred income taxes			2
Net loss on divestitures and investments			5
Equity-based compensation expense			17	4
Equity (gains) losses, including distributions			(51)	(60)
Changes in operating assets and liabilities:
Accounts receivable			(2)	18
Inventories			2
Royalty advances			(4)	(18)
Accounts payable and accrued liabilities			(5)	52
Royalty payables			54	36
Deferred revenue			(34)	3
Other balance sheet changes			10
Net cash (used in) provided by operating activities			205	202
Cash flows from investing activities
Acquisition of music publishing rights, net			(3)	(9)
Capital expenditures			(13)	(15)
Investments and acquisitions of businesses, net			(5)	(5)
Divestitures, net			7
Net cash (used in) provided by investing activities			(14)	(29)
Cash flows from financing activities
Dividends paid			(54)
Change in due to (from) issuer			(87)	(163)
Net cash (used in) provided by financing activities			(141)	(163)
Net increase in cash and equivalents			50	10
Cash and equivalents at beginning of period			180	73
Cash and equivalents at end of period	230	83	230	83
Reportable Legal Entities | Non-Guarantor Subsidiaries
Cash flows from operating activities
Net income	1	65	4	59
Adjustments to reconcile net income (loss) income to net cashprovided by operating activities:
Depreciation and amortization			56	70
Unrealized (gains)/losses and remeasurement of foreign denominated loans			13
Deferred income taxes			(12)	(10)
Gain on sale of real estate		(19)		(19)
Net loss on divestitures and investments			1	3
Changes in operating assets and liabilities:
Accounts receivable			(39)	7
Inventories			1	(1)
Royalty advances			5	(3)
Accounts payable and accrued liabilities			(4)	(73)
Royalty payables			21	(1)
Deferred revenue			30	(1)
Other balance sheet changes			(6)	3
Net cash (used in) provided by operating activities			70	34
Cash flows from investing activities
Acquisition of music publishing rights, net			(3)	(3)
Capital expenditures			(5)	(8)
Investments and acquisitions of businesses, net			(1)	(3)
Divestitures, net			11	6
Proceeds from the sale of real estate				42
Net cash (used in) provided by investing activities			2	34
Cash flows from financing activities
Distribution to noncontrolling interest holder			(1)	(3)
Repayment of capital lease obligations				(14)
Net cash (used in) provided by financing activities			(1)	(17)
Effect of exchange rate changes on cash and equivalents			(4)	(7)
Net increase in cash and equivalents			67	44
Cash and equivalents at beginning of period			179	173
Cash and equivalents at end of period	246	217	246	217
Reportable Legal Entities | WMG Acquisition Corp. Consolidated
Cash flows from operating activities
Net income	20	22	44	55
Adjustments to reconcile net income (loss) income to net cashprovided by operating activities:
Depreciation and amortization			126	150
Unrealized (gains)/losses and remeasurement of foreign denominated loans			(1)	(2)
Deferred income taxes			(12)	(10)
Gain on sale of real estate		(19)		(19)
(Gain)/Loss on extinguishment of debt			32	(1)
Net loss on divestitures and investments			6	3
Non-cash interest expense			5	5
Equity-based compensation expense			17	4
Changes in operating assets and liabilities:
Accounts receivable			(41)	25
Inventories			3	(1)
Royalty advances			1	(21)
Accounts payable and accrued liabilities			(43)	(41)
Royalty payables			75	35
Accrued interest			7	(1)
Deferred revenue			(4)	2
Other balance sheet changes			11	3
Net cash (used in) provided by operating activities			226	186
Cash flows from investing activities
Acquisition of music publishing rights, net			(6)	(12)
Capital expenditures			(18)	(23)
Investments and acquisitions of businesses, net			(6)	(8)
Divestitures, net			18	6
Proceeds from the sale of real estate				42
Net cash (used in) provided by investing activities			(12)	5
Cash flows from financing activities
Dividend by Acquisition Corp. to Holdings Corp.				(83)
Repayment of Acquisition Corp. Senior Term Loan Facility				(6)
Proceeds from issuance of Acquisition Corp. Senior Term Loan Facility			22
Call premiums paid on early redemption of debt			(27)
Deferred financing costs paid			(12)
Distribution to noncontrolling interest holder			(1)	(3)
Repayment of capital lease obligations				(14)
Dividends paid			(54)
Net cash (used in) provided by financing activities			(93)	(130)
Effect of exchange rate changes on cash and equivalents			(4)	(7)
Net increase in cash and equivalents			117	54
Cash and equivalents at beginning of period			359	246
Cash and equivalents at end of period	476	300	476	300
Reportable Legal Entities | WMG Holdings Corp.
Cash flows from operating activities
Net income	19	11	41	38
Adjustments to reconcile net income (loss) income to net cashprovided by operating activities:
(Gain)/Loss on extinguishment of debt				5
Equity (gains) losses, including distributions			(41)	(53)
Changes in operating assets and liabilities:
Accrued interest				(4)
Net cash (used in) provided by operating activities				(14)
Cash flows from financing activities
Dividend by Acquisition Corp. to Holdings Corp.				83
Call premiums paid on early redemption of debt				(3)
Net cash (used in) provided by financing activities				30
Net increase in cash and equivalents				16
Cash and equivalents at end of period		16		16
Reportable Legal Entities | Warner Music Group Corp.
Cash flows from operating activities
Net income	19	11	41	38
Adjustments to reconcile net income (loss) income to net cashprovided by operating activities:
Equity (gains) losses, including distributions			(41)	(38)
Reportable Legal Entities | 4.125% Senior Secured Notes | WMG Acquisition Corp.
Cash flows from financing activities
Proceeds from issuance of Acquisition Corp			380
Reportable Legal Entities | 4.125% Senior Secured Notes | WMG Acquisition Corp. Consolidated
Cash flows from financing activities
Proceeds from issuance of Acquisition Corp			380
Reportable Legal Entities | 4.875% Senior Secured Notes | WMG Acquisition Corp.
Cash flows from financing activities
Proceeds from issuance of Acquisition Corp			250
Reportable Legal Entities | 4.875% Senior Secured Notes | WMG Acquisition Corp. Consolidated
Cash flows from financing activities
Proceeds from issuance of Acquisition Corp			250
Reportable Legal Entities | 6.00% Senior Secured Notes | WMG Acquisition Corp.
Cash flows from financing activities
Repayment of Senior Secured Notes			(450)
Reportable Legal Entities | 6.00% Senior Secured Notes | WMG Acquisition Corp. Consolidated
Cash flows from financing activities
Repayment of Senior Secured Notes			(450)
Reportable Legal Entities | 6.25% Senior Secured Notes | WMG Acquisition Corp.
Cash flows from financing activities
Repayment of Senior Secured Notes			(173)
Reportable Legal Entities | 6.25% Senior Secured Notes | WMG Acquisition Corp. Consolidated
Cash flows from financing activities
Repayment of Senior Secured Notes			(173)
Reportable Legal Entities | 5.625% Senior Secured Notes | WMG Acquisition Corp.
Cash flows from financing activities
Repayment of Senior Secured Notes			(28)
Reportable Legal Entities | 5.625% Senior Secured Notes | WMG Acquisition Corp. Consolidated
Cash flows from financing activities
Repayment of Senior Secured Notes			(28)
Reportable Legal Entities | 13.75% Senior Notes | WMG Holdings Corp.
Cash flows from financing activities
Repayment of Senior Notes				(50)
Reportable Legal Entities | 6.75% Senior Notes | WMG Acquisition Corp.
Cash flows from financing activities
Repayment of Senior Notes				(24)
Reportable Legal Entities | 6.75% Senior Notes | WMG Acquisition Corp. Consolidated
Cash flows from financing activities
Repayment of Senior Notes				(24)
Eliminations
Cash flows from operating activities
Net income	(38)	(32)	(82)	(91)
Adjustments to reconcile net income (loss) income to net cashprovided by operating activities:
Equity (gains) losses, including distributions			82	91
Eliminations | WMG Acquisition Corp.
Cash flows from operating activities
Net income	$ (49)	$ (79)	(145)	(145)
Adjustments to reconcile net income (loss) income to net cashprovided by operating activities:
Deferred income taxes			(4)
Equity (gains) losses, including distributions			183	165
Changes in operating assets and liabilities:
Accounts payable and accrued liabilities			(34)	(20)
Cash flows from investing activities
Advances to issuer			(87)	(163)
Net cash (used in) provided by investing activities			(87)	(163)
Cash flows from financing activities
Change in due to (from) issuer			87	163
Net cash (used in) provided by financing activities			$ 87	$ 163