Revenues and Costs from Leases - Schedule of Sale Leaseback Transactions (Details) - USD ($) $ in Millions	Sep. 30, 2026	Jul. 31, 2025	Jun. 30, 2025
Lessee, Lease, Description [Line Items]
Future Minimum Payments	$ 5,050
Americas RAC
Lessee, Lease, Description [Line Items]
Future Minimum Payments	$ 149	$ 384	$ 483
Sale Leaseback Transaction April 2026 \| Americas RAC
Lessee, Lease, Description [Line Items]
Lease Terms	18 years
Future Minimum Payments	$ 19
Sale Leaseback Transaction One June 2026 \| Americas RAC
Lessee, Lease, Description [Line Items]
Lease Terms	1 year
Future Minimum Payments	$ 0
Sale Leaseback Transaction Two June 2026 \| Americas RAC
Lessee, Lease, Description [Line Items]
Lease Terms	13 years
Future Minimum Payments	$ 22
Sale Leaseback Transaction Three June 2026 \| Americas RAC
Lessee, Lease, Description [Line Items]
Lease Terms	15 years
Future Minimum Payments	$ 12
Sale Leaseback Transaction Four June 2026 \| Americas RAC
Lessee, Lease, Description [Line Items]
Lease Terms	15 years
Future Minimum Payments	$ 29
Sale Leaseback Transaction Five June 2026 \| Americas RAC
Lessee, Lease, Description [Line Items]
Lease Terms	20 years
Future Minimum Payments	$ 43
Sale Leaseback Transaction Six June 2026 \| Americas RAC
Lessee, Lease, Description [Line Items]
Lease Terms	20 years
Future Minimum Payments	$ 24