Description of Business - Additional Information (Detail)	6 Months Ended
	Mar. 31, 2017 Operations Country Musical_composition songwriters
Description Of Business [Line Items]
Number of fundamental operations | Operations	2
Number of countries in which Recorded Music activity conducted | Country	50
Minimum number of musical compositions on which Company owns or controls rights | Musical_composition	1,000,000
Number of songwriters and composers | songwriters	70,000
Parlophone Label Group
Description Of Business [Line Items]
Acquisition date	Jul. 01, 2013