Guarantor and Non-Guarantor Subsidiaries Financial Information - Consolidating Statement of Cash Flows Unaudited (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2016
Cash flows from operating activities
Net income	$ 5	$ 24	$ 24
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	65		63
Unrealized losses/gains and remeasurement of foreign denominated loans	5	(17)	(17)
Deferred income taxes	42	(2)	(2)
Loss on extinguishment of debt	1	32	32
Net gain on investments	(7)
Non-cash interest expense	1	3	3
Non-cash stock-based compensation expenses			10
Equity-based compensation expense	18	10
Changes in operating assets and liabilities:
Accounts receivable	(93)	(65)	(65)
Inventories	2	3	3
Royalty advances	(5)	1	1
Accounts payable and accrued liabilities	(23)	(12)	(12)
Royalty payables	141	112	112
Accrued interest	(16)	(10)	(10)
Deferred revenue	(3)	(1)	(1)
Other balance sheet changes	3	15	15
Net cash provided by operating activities	136	156	156
Cash flows from investing activities
Acquisition of music publishing rights, net	(1)	(1)	(1)
Capital expenditures	(16)	(8)	(8)
Investments and acquisitions of businesses, net	(1)	(3)	(3)
Proceeds from the sale of investments	12
Net cash (used in) provided by investing activities	(6)	(12)	(12)
Cash flows from financing activities
Proceeds from issuance of Acquisition Corp. Senior Term Loan Facility		22	22
Financing costs paid			(27)
Call premiums paid on early redemption of debt		(27)
Deferred financing costs paid	(1)	(12)	(12)
Distribution to noncontrolling interest holder	(2)
Net cash (used in) provided by financing activities	(3)	(38)	(38)
Effect of exchange rate changes on cash and equivalents	2	(10)	(10)
Net increase in cash and equivalents	129	96	96
Cash and equivalents at beginning of period	647	359	359
Cash and equivalents at end of period	776	455	455
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)
Reportable Legal Entities | Guarantor Subsidiaries
Cash flows from operating activities
Net income	34	95	95
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	32		35
Unrealized losses/gains and remeasurement of foreign denominated loans	1		(9)
Net gain on investments	(7)
Non-cash stock-based compensation expenses			10
Equity-based compensation expense	18
Equity (gains) losses, including distributions	(43)		(40)
Changes in operating assets and liabilities:
Accounts receivable	(33)		(19)
Inventories			2
Royalty advances	5		7
Accounts payable and accrued liabilities	65		6
Royalty payables	59		40
Deferred revenue	17		(33)
Other balance sheet changes	37		12
Net cash provided by operating activities	185		106
Cash flows from investing activities
Capital expenditures	(13)		(6)
Investments and acquisitions of businesses, net	(1)		(3)
Proceeds from the sale of investments	12
Net cash (used in) provided by investing activities	(2)		(9)
Cash flows from financing activities
Change in due to (from) issuer	(95)		(95)
Net cash (used in) provided by financing activities	(95)		(95)
Net increase in cash and equivalents	88		2
Cash and equivalents at beginning of period	347		180
Cash and equivalents at end of period	435	182	182
Reportable Legal Entities | Non-Guarantor Subsidiaries
Cash flows from operating activities
Net income	41	3	3
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	33		28
Unrealized losses/gains and remeasurement of foreign denominated loans	(2)		13
Deferred income taxes	42		(2)
Changes in operating assets and liabilities:
Accounts receivable	(60)		(46)
Inventories	2		1
Royalty advances	(10)		(6)
Accounts payable and accrued liabilities	(29)		9
Royalty payables	82		72
Deferred revenue	(20)		32
Other balance sheet changes	(34)		3
Net cash provided by operating activities	45		107
Cash flows from investing activities
Acquisition of music publishing rights, net	(1)		(1)
Capital expenditures	(3)		(2)
Net cash (used in) provided by investing activities	(4)		(3)
Cash flows from financing activities
Distribution to noncontrolling interest holder	(2)
Net cash (used in) provided by financing activities	(2)
Effect of exchange rate changes on cash and equivalents	2		(10)
Net increase in cash and equivalents	41		94
Cash and equivalents at beginning of period	300		179
Cash and equivalents at end of period	341	273	273
Reportable Legal Entities | Warner Music Group Corp.
Cash flows from operating activities
Net income	4	22	22
Adjustments to reconcile net income to net cash provided by operating activities:
Equity (gains) losses, including distributions	(4)		(22)
Reportable Legal Entities | WMG Acquisition Corp.
Cash flows from operating activities
Net income	4	22	22
Adjustments to reconcile net income to net cash provided by operating activities:
Unrealized losses/gains and remeasurement of foreign denominated loans	6		(21)
Loss on extinguishment of debt	1	32	32
Non-cash interest expense	1		3
Equity (gains) losses, including distributions	(90)		(83)
Changes in operating assets and liabilities:
Accrued interest	(16)		(10)
Net cash provided by operating activities	(94)		(57)
Cash flows from investing activities
Advances (from) to issuer	95		95
Net cash (used in) provided by investing activities	95		95
Cash flows from financing activities
Proceeds from issuance of Acquisition Corp. Senior Term Loan Facility			22
Financing costs paid			(27)
Deferred financing costs paid	(1)		(12)
Net cash (used in) provided by financing activities	(1)		(38)
Reportable Legal Entities | WMG Acquisition Corp. Consolidated
Cash flows from operating activities
Net income	5	24	24
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	65		63
Unrealized losses/gains and remeasurement of foreign denominated loans	5		(17)
Deferred income taxes	42		(2)
Loss on extinguishment of debt	1	32	32
Net gain on investments	(7)
Non-cash interest expense	1		3
Non-cash stock-based compensation expenses			10
Equity-based compensation expense	18
Changes in operating assets and liabilities:
Accounts receivable	(93)		(65)
Inventories	2		3
Royalty advances	(5)		1
Accounts payable and accrued liabilities	(23)		(12)
Royalty payables	141		112
Accrued interest	(16)		(10)
Deferred revenue	(3)		(1)
Other balance sheet changes	3		15
Net cash provided by operating activities	136		156
Cash flows from investing activities
Acquisition of music publishing rights, net	(1)		(1)
Capital expenditures	(16)		(8)
Investments and acquisitions of businesses, net	(1)		(3)
Proceeds from the sale of investments	12
Net cash (used in) provided by investing activities	(6)		(12)
Cash flows from financing activities
Proceeds from issuance of Acquisition Corp. Senior Term Loan Facility			22
Financing costs paid			(27)
Deferred financing costs paid	(1)		(12)
Distribution to noncontrolling interest holder	(2)
Net cash (used in) provided by financing activities	(3)		(38)
Effect of exchange rate changes on cash and equivalents	2		(10)
Net increase in cash and equivalents	129		96
Cash and equivalents at beginning of period	647		359
Cash and equivalents at end of period	776	455	455
Reportable Legal Entities | WMG Holdings Corp.
Cash flows from operating activities
Net income	4	22	22
Adjustments to reconcile net income to net cash provided by operating activities:
Equity (gains) losses, including distributions	(4)		(22)
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)
Eliminations
Cash flows from operating activities
Net income	(8)	(44)	(44)
Adjustments to reconcile net income to net cash provided by operating activities:
Equity (gains) losses, including distributions	8		44
Eliminations | WMG Acquisition Corp.
Cash flows from operating activities
Net income	(74)	$ (96)	(96)
Adjustments to reconcile net income to net cash provided by operating activities:
Equity (gains) losses, including distributions	133		123
Changes in operating assets and liabilities:
Accounts payable and accrued liabilities	(59)		(27)
Cash flows from investing activities
Advances (from) to issuer	(95)		(95)
Net cash (used in) provided by investing activities	(95)		(95)
Cash flows from financing activities
Change in due to (from) issuer	95		95
Net cash (used in) provided by financing activities	$ 95		$ 95