Annual report pursuant to Section 13 and 15(d)

Employee Benefit Plans - Additional Information (Detail)

v3.21.1
Employee Benefit Plans - Additional Information (Detail)
 12 Months Ended
Mar. 31, 2021
USD ($)
$ / Employee
Mar. 31, 2020
USD ($)
Mar. 31, 2019
USD ($)
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 $ 32,861,000 $ 31,715,000  
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 2026    
Medical care cost trend rate decrements 0.50%    
Current portion of accrued postretirement benefit obligation $ 72,000 77,000  
Stop loss coverage per employee for claims | $ / Employee 100    
Maximum aggregate stop loss coverage | $ / Employee 1,000    
Total plan amount $ 2,744,000    
Self-Insured medical plan liability 184,000 124,000  
Defined Contribution Plan 401K [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Contributions to defined contribution plan 863,000 1,000,000 $ 1,135,000
Pension Plans, Defined Benefit [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Contributions expected during fiscal 2021 0    
Liability released through annuity purchase 1,477,000 1,420,000  
Annuities purchased 1,477,000 1,420,000  
Pension expense $ 198,000 $ 98,000 $ (305,000)
Weighted average discount rates used to develop net postretirement benefit cost 3.44% 3.83% 3.95%
Weighted average rate of increase in compensation levels 3.00% 3.00% 3.00%
Projected benefit obligation $ 36,320,000 $ 35,783,000 $ 34,149,000
Net actuarial loss recognized in accumulated other comprehensive loss, net of income tax 6,990,000 9,285,000  
Defined Contribution Plan [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Contributions to defined contribution plan 430,000 406,000 325,000
Supplemental Executive Retirement Plan [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Pension expense $ 105,000 $ 85,000 $ 97,000
Weighted average discount rates used to develop net postretirement benefit cost 3.44% 3.83% 3.95%
Weighted average rate of increase in compensation levels 3.00% 3.00% 3.00%
Projected benefit obligation $ 1,557,000 $ 747,000  
Net actuarial loss recognized in accumulated other comprehensive loss, net of income tax 544,000 0  
Other Postretirement Benefit Plans [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Pension expense $ 45,000 $ 50,000 $ 53,000
Weighted average discount rates used to develop net postretirement benefit cost 3.01% 3.37% 3.63%
Projected benefit obligation $ 587,000 $ 634,000 $ 682,000
Net actuarial loss recognized in accumulated other comprehensive loss, net of income tax $ 164,000 $ 187,000