v3.26.1
RETIREMENT-RELATED BENEFITS - Nonpension Postretirement Benefits Plans and Multi-Employer Plans (Details) - USD ($)
$ in Millions
12 Months Ended
Mar. 31, 2026
Mar. 31, 2025
Mar. 31, 2024
RETIREMENT-RELATED BENEFITS      
Cost of defined contribution expense $ 137.0 $ 131.0 $ 140.0
Retirement and nonpension postretirement benefit obligations 490.0 483.0  
Non Pension Postretirement Benefit Plans      
RETIREMENT-RELATED BENEFITS      
Retirement and nonpension postretirement benefit obligations $ 8.0 $ 9.0  
Discount rate 3.97% 3.16% 2.89%
Fair Value of plan assets $ 0.0 $ 0.0 $ 0.0