Description of Business - Additional Information (Detail)	9 Months Ended
	Jun. 30, 2019 musical_composition country songwriter
Organization, Consolidation and Presentation of Financial Statements [Abstract]
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 | songwriter	70,000