v3.26.1
RETIREMENT-RELATED BENEFITS - OCI and AOCI (Details) - USD ($)
$ in Millions
12 Months Ended
Mar. 31, 2026
Mar. 31, 2025
Mar. 31, 2024
Changes in AOCI for retirement-related benefits      
Current period loss (gain) $ (64) $ (17) $ 56
Curtailments and settlements (10) (7) (10)
Amortization of net loss included in net periodic benefit cost (10) (16) (5)
Current period prior service costs (credits) 34 (2) 3
Pension Plans      
Changes in AOCI for retirement-related benefits      
Net loss (gain) at beginning of period 256 296  
Current period loss (gain) (63) (17)  
Curtailments and settlements (10) (8)  
Amortization of net loss included in net periodic benefit cost (10) (16)  
Net loss (gain) at end of period 173 256 296
Prior service costs (credits) at beginning of period 1 4  
Current period prior service costs (credits) 35 (2)  
Amortization for prior service costs (credits) included in net periodic benefit cost (3) (1)  
Prior service costs (credits) at end of period 34 1 $ 4
Total amounts recognized in accumulated other comprehensive loss (income) $ 207 $ 257