Restructuring and Impairments - Narrative (Details) - USD ($) $ in Millions		12 Months Ended
	Jul. 01, 2025	Sep. 30, 2026	Sep. 30, 2025
Recorded Music
Restructuring Cost and Reserve [Line Items]
Other impairments			$ 79
2025 Restructuring Plan
Restructuring Cost and Reserve [Line Items]
Pre-tax basis	$ 200
After-tax basis	150
Cash expenditures	200
2025 Restructuring Plan | Forecast
Restructuring Cost and Reserve [Line Items]
Payments for restructuring		$ 170
2025 Restructuring Plan | Severance Costs
Restructuring Cost and Reserve [Line Items]
Pre-tax basis	170
Payments for restructuring			5
Restructuring and impairments			90
2025 Restructuring Plan | Severance And Other Termination Costs
Restructuring Cost and Reserve [Line Items]
Severance costs			90
Non-cash impairments and restructuring			28
2025 Restructuring Plan | Severance And Other Termination Costs | Operating Segments | Recorded Music
Restructuring Cost and Reserve [Line Items]
Severance costs			74
Non-cash impairments and restructuring			6
2025 Restructuring Plan | Severance And Other Termination Costs | Operating Segments | Music Publishing
Restructuring Cost and Reserve [Line Items]
Severance costs			5
2025 Restructuring Plan | Severance And Other Termination Costs | Corporate Expenses and Eliminations
Restructuring Cost and Reserve [Line Items]
Severance costs			11
Non-cash impairments and restructuring			22
2025 Restructuring Plan | Other Non-cash Charges
Restructuring Cost and Reserve [Line Items]
Pre-tax basis	$ 30
2024 Strategic Restructuring Plan
Restructuring Cost and Reserve [Line Items]
Payments for restructuring			80
Cumulative restructuring and impairment charges			216
Restructuring and impairments			6
2024 Strategic Restructuring Plan | Recorded Music
Restructuring Cost and Reserve [Line Items]
Non-cash impairments and restructuring			32
2024 Strategic Restructuring Plan | Operating Segments | Recorded Music
Restructuring Cost and Reserve [Line Items]
Cumulative restructuring and impairment charges			206
2024 Strategic Restructuring Plan | Corporate Expenses and Eliminations
Restructuring Cost and Reserve [Line Items]
Cumulative restructuring and impairment charges			10
2024 Strategic Restructuring Plan | Severance Costs
Restructuring Cost and Reserve [Line Items]
Payments for restructuring			75
Restructuring and impairments			(1)
2024 Strategic Restructuring Plan | Severance And Other Termination Costs
Restructuring Cost and Reserve [Line Items]
Severance costs			6
Restructuring and impairments			$ 134
Restructuring Charges, Statement of Income or Comprehensive Income [Extensible Enumeration]			Restructuring & Impairment
2024 Strategic Restructuring Plan | Severance And Other Termination Costs | Operating Segments | Recorded Music
Restructuring Cost and Reserve [Line Items]
Severance costs			$ 8
2024 Strategic Restructuring Plan | Severance And Other Termination Costs | Corporate Expenses and Eliminations
Restructuring Cost and Reserve [Line Items]
Severance costs			2
2024 Strategic Restructuring Plan | Other Non-cash Charges
Restructuring Cost and Reserve [Line Items]
Restructuring and impairments			7
2024 Strategic Restructuring Plan | Property Wind Down
Restructuring Cost and Reserve [Line Items]
Restructuring and impairments			$ 82