v3.25.2
Accumulated Other Comprehensive Income (Loss) (Details) - USD ($)
$ in Millions
 3 Months Ended 9 Months Ended
Jun. 30, 2025
Jun. 30, 2024
Jun. 30, 2025
Jun. 30, 2024
AOCI Attributable to Parent, Net of Tax        
Balance, beginning of period     $ 4,354  
Other comprehensive income (loss) $ 87 $ (15) 72 $ (13)
Balance, end of period 4,884 4,690 4,884 4,690
Total        
AOCI Attributable to Parent, Net of Tax        
Balance, beginning of period (268) (254) (253) (256)
Other comprehensive income (loss) before reclassification adjustments 87 (6) 73 16
Amounts reclassified from AOCI 0 (9) (1) (29)
Other comprehensive income (loss) 87 (15) 72 (13)
Balance, end of period (181) (269) (181) (269)
Postretirement Benefit Plans        
AOCI Attributable to Parent, Net of Tax        
Balance, beginning of period 10 16 10 17
Other comprehensive income (loss) before reclassification adjustments 0 0 0 0
Amounts reclassified from AOCI 1 0 1 (1)
Other comprehensive income (loss) 1 0 1 (1)
Balance, end of period 11 16 11 16
Derivative Instruments        
AOCI Attributable to Parent, Net of Tax        
Balance, beginning of period (13) 4 (23) 26
Other comprehensive income (loss) before reclassification adjustments (2) 4 9 1
Amounts reclassified from AOCI (1) (9) (2) (28)
Other comprehensive income (loss) (3) (5) 7 (27)
Balance, end of period (16) (1) (16) (1)
Foreign Currency        
AOCI Attributable to Parent, Net of Tax        
Balance, beginning of period (265) (274) (240) (299)
Other comprehensive income (loss) before reclassification adjustments 89 (10) 64 15
Amounts reclassified from AOCI 0 0 0 0
Other comprehensive income (loss) 89 (10) 64 15
Balance, end of period $ (176) $ (284) $ (176) $ (284)