v3.25.1
Accumulated Other Comprehensive Income (Loss) (Details) - USD ($)
$ in Millions
 3 Months Ended 6 Months Ended
Mar. 31, 2025
Mar. 31, 2024
Mar. 31, 2025
Mar. 31, 2024
AOCI Attributable to Parent, Net of Tax        
Balance, beginning of period     $ 4,354  
Other comprehensive income (loss) before reclassification adjustments $ 43 $ (12) (14) $ 22
Amounts reclassified from AOCI 2 (10) (1) (20)
Other comprehensive income (loss) 45 (22) (15) 2
Balance, end of period 5,021 4,831 5,021 4,831
Total        
AOCI Attributable to Parent, Net of Tax        
Balance, beginning of period (313) (232) (253) (256)
Balance, end of period (268) (254) (268) (254)
Postretirement Benefit Plans        
AOCI Attributable to Parent, Net of Tax        
Balance, beginning of period 9 17 10 17
Other comprehensive income (loss) before reclassification adjustments 0 0 0 0
Amounts reclassified from AOCI 1 (1) 0 (1)
Other comprehensive income (loss) 1 (1) 0 (1)
Balance, end of period 10 16 10 16
Derivative Instruments        
AOCI Attributable to Parent, Net of Tax        
Balance, beginning of period (10) 1 (23) 26
Other comprehensive income (loss) before reclassification adjustments (4) 12 11 (3)
Amounts reclassified from AOCI 1 (9) (1) (19)
Other comprehensive income (loss) (3) 3 10 (22)
Balance, end of period (13) 4 (13) 4
Foreign Currency        
AOCI Attributable to Parent, Net of Tax        
Balance, beginning of period (312) (250) (240) (299)
Other comprehensive income (loss) before reclassification adjustments 47 (24) (25) 25
Amounts reclassified from AOCI 0 0 0 0
Other comprehensive income (loss) 47 (24) (25) 25
Balance, end of period $ (265) $ (274) $ (265) $ (274)