Restructuring - Summary of Charges in Consolidated Statement of Operations (Detail) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2015	Sep. 30, 2014
Restructuring Cost And Reserve [Line Items]
Total restructuring expense	$ 2
Recorded Music
Restructuring Cost And Reserve [Line Items]
Total restructuring expense	2	$ 50
Recorded Music | Selling, General and Administrative Expenses
Restructuring Cost And Reserve [Line Items]
Total restructuring expense	$ 2	$ 50