v3.26.1
Employee Benefit Plans - Schedule of Assumed Health Care Cost Trend Rates (Details) - Officer Medical Plan - Other Postretirement Benefits Plan
 12 Months Ended
Mar. 31, 2026
Mar. 31, 2025
Defined Benefit Plan Disclosure [Line Items]    
Health care cost trend rate assumed for next year, Pre 65 8.10% 8.25%
Rate to which the cost trend rate is assumed to decline (the ultimate trend rate), Pre 65 4.50% 4.50%
Health care cost trend rate assumed for next year, Post 65 9.20% 8.95%
Rate to which the cost trend rate is assumed to decline (the ultimate trend rate), Post 65 4.50% 4.50%