Consolidated Statements of Comprehensive Income (Loss) (Unaudited) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Mar. 31, 2017	Mar. 31, 2016
Statement Of Income And Comprehensive Income [Abstract]
Net income	$ 20	$ 12	$ 44	$ 40
Other comprehensive income (loss), net of tax:
Foreign currency adjustment	24	(12)	(13)	(36)
Deferred gains (losses) on derivative financial instruments	1	(1)	(1)	(2)
Other comprehensive income (loss), net of tax	25	(13)	(14)	(38)
Total comprehensive income (loss)	45	(1)	30	2
Less: Income attributable to noncontrolling interest	(1)	(1)	(3)	$ (2)
Comprehensive income (loss) attributable to Warner Music Group Corp.	$ 44	$ (2)	$ 27