Annual report pursuant to Section 13 and 15(d)

Employee Benefit Plans - Additional Information (Detail)

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Employee Benefit Plans - Additional Information (Detail) - USD ($)
 12 Months Ended
Mar. 31, 2023
Mar. 31, 2022
Mar. 31, 2021
Defined Benefit Plan Disclosure [Line Items]      
Employee's years of service and average earnings five highest consecutive calendar years of compensation in the ten-year period preceding retirement    
Accumulated benefit obligation $ 23,784,000 $ 29,943,000  
Contribution equal to employee salary deferral 100.00%    
Employer contribution description matching contributions equal to 100% of the first 3% of an employee's salary deferral and 50% of the next 2% percent of an employee’s salary deferral    
Contribution next to employee salary deferral 3.00%    
Contribution for additional employee salary deferral 50.00%    
Contribution additional next to employee salary deferral 2.00%    
Share of the medical premium cost for family coverage $ 4,000    
Share of the medical premium cost for single coverage 2,000    
Share of the medical premium both family and single coverage for regular retirees $ 1,000    
Medical care cost trend rate 4.50%    
Medical care trend year 2027    
Medical care cost trend rate decrements 0.50%    
Current portion of accrued postretirement benefit obligation $ 49,000 63,000  
Defined Contribution Plan 401K [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Contributions to defined contribution plan 1,904,000 1,365,000 $ 863,000
Pension Plans, Defined Benefit [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Contributions expected during fiscal 2021 0    
Liability released through annuity purchase 1,383,000 1,279,000  
Annuities purchased 1,383,000 1,279,000  
Pension expense $ (18,000) $ (538,000) $ 198,000
Weighted average discount rates used to develop net postretirement benefit cost 3.66% 3.21% 3.44%
Weighted average rate of increase in compensation levels 3.00% 3.00% 3.00%
Projected benefit obligation $ 26,646,000 $ 32,991,000 $ 36,320,000
Net actuarial loss recognized in accumulated other comprehensive loss, net of income tax 7,506,000 6,753,000  
Defined Contribution Plan [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Contributions to defined contribution plan 1,030,000 710,000 430,000
Supplemental Executive Retirement Plan [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Pension expense $ 74,000 $ 346,000 $ 105,000
Weighted average discount rates used to develop net postretirement benefit cost 3.64% 3.21% 3.44%
Weighted average rate of increase in compensation levels 3.00% 3.00% 3.00%
Projected benefit obligation $ 1,104,000 $ 1,320,000  
Net actuarial loss recognized in accumulated other comprehensive loss, net of income tax (47,000) (123,000)  
Other Postretirement Benefit Plans [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Pension expense $ 27,000 $ 38,000 $ 45,000
Weighted average discount rates used to develop net postretirement benefit cost 3.32% 2.34% 3.01%
Projected benefit obligation $ 355,000 $ 478,000 $ 587,000
Net actuarial loss recognized in accumulated other comprehensive loss, net of income tax $ 11,000 $ 94,000