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Balance held at close of period in number of shares.

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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The number of countries in which the entity operates as of balance sheet date.

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The number of shares issued or sold by the subsidiary or equity method investee per stock transaction.

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Percentage of subsidiary's or equity investee's stock owned by parent company after stock transaction.

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Per share amount received by subsidiary or equity investee for each share of common stock issued or sold in the stock transaction.

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Minimum number of musical compositions on which rights are owned or controlled.

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Number of songwriters and composers.

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Sale Of Stock, Percentage Of Economic Interest

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Description of Business - Additional Information (Detail) songwriter in Thousands, musical_composition in Millions			9 Months Ended
	Jul. 07, 2020 shares	Jun. 05, 2020 $ / shares shares	Jun. 30, 2020 musical_composition country $ / shares songwriter shares	Sep. 30, 2019 $ / shares
Subsidiary, Sale of Stock [Line Items]
Number of countries in which Recorded Music activity conducted (more than) \| country			70
Minimum number of musical compositions on which Company owns or controls rights (more than) \| musical_composition			1.4
Number of songwriters and composers (over) \| songwriter			80
Access Industries
Subsidiary, Sale of Stock [Line Items]
Percentage of voting power		99.00%
Percentage of economic interest		83.00%
Class A Common Stock
Subsidiary, Sale of Stock [Line Items]
Par value (in dollars per share)			$ 0.001	$ 0.001
Class B Common Stock
Subsidiary, Sale of Stock [Line Items]
Par value (in dollars per share)			0.001	$ 0.001
Class B Common Stock \| Access Industries
Subsidiary, Sale of Stock [Line Items]
Par value (in dollars per share)			$ 0.001
Investment owned (in shares) \| shares			421,450,000
IPO \| Class A Common Stock
Subsidiary, Sale of Stock [Line Items]
Number of shares issued in transaction (in shares) \| shares		77,000,000
Par value (in dollars per share)		$ 0.001
Price per share (in dollars per share)		$ 25
Over-Allotment Option \| Class A Common Stock \| Subsequent Event
Subsidiary, Sale of Stock [Line Items]
Number of shares issued in transaction (in shares) \| shares	11,550,000