Goodwill and Other Intangible Assets - Narrative (Details) $ in Millions	3 Months Ended	6 Months Ended	9 Months Ended
	Mar. 31, 2025 USD ($)	Mar. 31, 2025 USD ($) segment	Jun. 30, 2025 USD ($) segment	Jun. 30, 2024 USD ($)	Sep. 30, 2024 USD ($)
Finite-Lived Intangible Assets [Line Items]
Number of reportable segments | segment		3	3
Impairment			$ 333
Goodwill			1,804		$ 2,164
Amortization of intangibles			35	$ 35
EMEA
Finite-Lived Intangible Assets [Line Items]
Impairment			333
Goodwill	$ 0	$ 0	$ 0		$ 341
Minimum | Significant Unobservable Inputs (Level 3) | Measurement Input, Cap Rate | Valuation, Income Approach
Finite-Lived Intangible Assets [Line Items]
Reporting unit, measurement input	16.50%
Maximum | Significant Unobservable Inputs (Level 3) | Measurement Input, Cap Rate | Valuation, Income Approach
Finite-Lived Intangible Assets [Line Items]
Reporting unit, measurement input	21.00%