v3.26.1
EQUITY - Reclassifications and Taxes (Details) - USD ($)
$ in Millions
 12 Months Ended
Mar. 31, 2026
Mar. 31, 2025
Mar. 31, 2024
Reclassifications and Taxes Related to Items of Other Comprehensive Income (Loss)      
Other comprehensive income (loss) $ 86 $ (16) $ (82)
Other comprehensive income (loss)      
Reclassifications and Taxes Related to Items of Other Comprehensive Income (Loss)      
Other comprehensive income (loss), before tax amount 100 (6) (88)
Other comprehensive income (loss), tax (expense) benefit (14) (10) 6
Other comprehensive income (loss) 86 (16) (82)
Foreign currency translation adjustments      
Reclassifications and Taxes Related to Items of Other Comprehensive Income (Loss)      
Other comprehensive income (loss), before tax amount 53 (46) (47)
Other comprehensive income (loss), tax (expense) benefit 2 (2)  
Other comprehensive income (loss) 55 (48) (47)
Foreign currency translation adjustments excluding net investment hedges      
Reclassifications and Taxes Related to Items of Other Comprehensive Income (Loss)      
Unrealized gains (losses) arising during the period, before tax amount 127 (50) (36)
Unrealized gains (losses) arising during the period, net of tax amount 127 (50) (36)
Unrealized gains (losses) on net investment hedges      
Reclassifications and Taxes Related to Items of Other Comprehensive Income (Loss)      
Unrealized gains (losses) arising during the period, before tax amount (75) 4 (11)
Unrealized gains (losses) arising during the period, tax (expense) benefit 2 (2)  
Unrealized gains (losses) arising during the period, net of tax amount (73) 2 (11)
Unrealized gains (losses) on cash flow hedges      
Reclassifications and Taxes Related to Items of Other Comprehensive Income (Loss)      
Unrealized gains (losses) arising during the period, before tax amount 2 (14) 22
Unrealized gains (losses) arising during the period, tax (expense) benefit   3 (1)
Unrealized gains (losses) arising during the period, net of tax amount 2 (11) 21
Reclassification/amortization, before tax amount (8) 11 (21)
Reclassification/amortization, tax (expense) benefit (1)    
Reclassification/amortization, net of tax amount (9) 11 (21)
Other comprehensive income (loss), before tax amount (6) (2) 1
Other comprehensive income (loss), tax (expense) benefit (1) 3 (1)
Other comprehensive income (loss) (7)    
Total retirement-related benefit plans      
Reclassifications and Taxes Related to Items of Other Comprehensive Income (Loss)      
Other comprehensive income (loss), before tax amount 53 42 (42)
Other comprehensive income (loss), tax (expense) benefit (16) (10) 7
Other comprehensive income (loss) 38 32 (36)
Retirement-related benefit plans, Prior service (costs) credits      
Reclassifications and Taxes Related to Items of Other Comprehensive Income (Loss)      
Unrealized gains (losses) arising during the period, before tax amount (34) 2 (3)
Unrealized gains (losses) arising during the period, tax (expense) benefit 9 (1) 1
Unrealized gains (losses) arising during the period, net of tax amount (25) 1 (2)
Reclassification/amortization, before tax amount 2   1
Reclassification/amortization, tax (expense) benefit (1)    
Reclassification/amortization, net of tax amount 2   1
Retirement-related benefit plans, net gains (losses)      
Reclassifications and Taxes Related to Items of Other Comprehensive Income (Loss)      
Unrealized gains (losses) arising during the period, before tax amount 64 17 (56)
Unrealized gains (losses) arising during the period, tax (expense) benefit (18) (4) 10
Unrealized gains (losses) arising during the period, net of tax amount 46 13 (45)
Reclassification/amortization, before tax amount 10 16 5
Reclassification/amortization, tax (expense) benefit (3) (4) (2)
Reclassification/amortization, net of tax amount 7 12 3
Retirement-related benefit plans, curtailments and settlements      
Reclassifications and Taxes Related to Items of Other Comprehensive Income (Loss)      
Unrealized gains (losses) arising during the period, before tax amount 10 7 10
Unrealized gains (losses) arising during the period, tax (expense) benefit (3) (2) (2)
Unrealized gains (losses) arising during the period, net of tax amount $ 8 $ 5 $ 8