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Summary of Significant Accounting Policies - Additional Information (Details) $ / shares in Units, $ in Millions			4 Months Ended	12 Months Ended
	Jun. 05, 2020 USD ($) shares	Feb. 28, 2020 $ / shares shares	Sep. 30, 2020 USD ($) shares	Sep. 30, 2021 USD ($) shares	Sep. 30, 2020 USD ($) shares	Sep. 30, 2019 USD ($)
Accounting Policies [Line Items]
Capital stock authorized (in shares)		2,100,000,000
Preferred stock,, authorized (in shares)		100,000,000
Preferred stock, par value (in dollars per share) | $ / shares		$ 1.00
Stockholders' equity note, stock split, conversion ratio		477,242.614671815
Advertising expense | $				$ 149	$ 115	$ 108
Award requisite service period				4 years
Modification of stock-based compensation plan | $					769
Non-cash compensation expense | $				$ 45	608	$ 50
Share-based Payment Arrangement
Accounting Policies [Line Items]
Non-cash compensation expense | $			$ 11
IPO
Accounting Policies [Line Items]
Preferred stock, outstanding (in shares)	0
Award requisite service period				1 year
Modification of stock-based compensation plan | $	$ 769
Additional Paid-in Capital
Accounting Policies [Line Items]
Modification of stock-based compensation plan | $	769				$ 769
Additional Paid-in Capital | IPO Tag-Along Right
Accounting Policies [Line Items]
Modification of stock-based compensation plan | $	$ 57
Furniture and fixtures | Minimum
Accounting Policies [Line Items]
Property plant and equipment useful life				5 years
Furniture and fixtures | Maximum
Accounting Policies [Line Items]
Property plant and equipment useful life				7 years
Computer Equipment | Maximum
Accounting Policies [Line Items]
Property plant and equipment useful life				5 years
Machinery and equipment | Maximum
Accounting Policies [Line Items]
Property plant and equipment useful life				13 years
Building | Maximum
Accounting Policies [Line Items]
Property plant and equipment useful life				40 years
Spotify | Credit Concentration Risk | Accounts Receivable
Accounting Policies [Line Items]
Customer concentration percentage				18.00%	16.00%
Common Class A
Accounting Policies [Line Items]
Common stock authorized (in shares)		1,000,000,000	1,000,000,000	1,000,000,000	1,000,000,000
Common stock outstanding (in shares)			88,578,361	122,414,827	88,578,361
Common Class A | IPO
Accounting Policies [Line Items]
Common stock outstanding (in shares)	88,550,000
Common Class B
Accounting Policies [Line Items]
Common stock authorized (in shares)		1,000,000,000	1,000,000,000	1,000,000,000	1,000,000,000
Common stock outstanding (in shares)		510,000,000	421,450,000	391,970,996	421,450,000
Conversion of Class B shares				10,244,898
Common Class B | IPO
Accounting Policies [Line Items]
Common stock outstanding (in shares)	421,450,000

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