Annual report pursuant to Section 13 and 15(d)

Employee Benefit Plans - Additional Information (Detail)

v2.4.0.8
Employee Benefit Plans - Additional Information (Detail) (USD $)
In Thousands, unless otherwise specified
 12 Months Ended
Mar. 31, 2014
Mar. 31, 2013
Mar. 31, 2012
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 $ 28,254 $ 27,809  
Employer contribution description Matching contributions equal to 100 percent of the first 3% of an employee's salary deferral and 50% of the next two percent of an employee's salary deferral    
Contribution equal to employee salary deferral 100.00%    
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    
Share of the medical premium cost for single coverage 2    
Share of the medical premium both family and single coverage for regular retirees 1    
Medical care cost trend rate 5.00%    
Medical care trend year 2020    
Medical care cost trend rate decrements 0.50%    
Current portion of accrued postretirement benefit obligation 98 107  
Employee stock ownership plan, shares 252 279  
Company contributions to the ESOP 0 0 0
Stop loss coverage per employee for claims 100    
Maximum aggregate stop loss coverage 1,000    
Total plan amount 3,707    
Self-Insured medical plan liability 221    
Defined Contribution Pension [Member]
      
Defined Benefit Plan Disclosure [Line Items]      
Contributions to defined contribution plan 257 204 161
Pension Plans, Defined Benefit [Member]
      
Defined Benefit Plan Disclosure [Line Items]      
Estimated net actuarial loss for pension plan 580    
Estimated prior service cost for pension plan 4    
Pension expense 213 248 (312)
Weighted average discount rate used to develop net postretirement benefit cost 4.28% 4.76% 5.63%
Supplemental Executive Retirement Plan [Member]
      
Defined Benefit Plan Disclosure [Line Items]      
Pension expense 70 24 21
Pension expense related liability 298 254  
Current portion of the related liability included in accrued compensation 26 27  
401K Plan [Member]
      
Defined Benefit Plan Disclosure [Line Items]      
Contributions to defined contribution plan 831 753 457
Other Postretirement Benefit Plans [Member]
      
Defined Benefit Plan Disclosure [Line Items]      
Estimated net actuarial loss for pension plan 40    
Estimated prior service cost for pension plan (106)    
Pension expense $ (87) $ (83) $ (84)
Weighted average discount rate used to develop net postretirement benefit cost 3.26% 3.96% 4.69%