Annual report pursuant to Section 13 and 15(d)

Stock Compensation Plans - Additional Information (Detail)

v3.8.0.1
Stock Compensation Plans - Additional Information (Detail) - USD ($)
$ in Thousands
12 Months Ended
Mar. 31, 2018
Mar. 31, 2017
Mar. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Cash proceeds from the exercise of stock options $ 0 $ 137 $ 97
Total intrinsic value of the stock options exercised $ 0 113 71
Options, stock awards and performance awards available for future grants 280,000    
Stock Compensation Plan [Member]      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Stock based compensation expense $ 577 621 653
Income tax benefit to stock based compensation 125 219 230
Increase (decrease) in capital in excess of par value for the income tax (expense) benefit realized upon exercise of stock options and vesting of restricted shares $ 0 $ (19) $ 5
Restricted Stock [Member]      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Restricted stock awarded 59,000 82,000 34,000
Unrecognized stock-based compensation expense $ 1,843    
Weighted average period for recognize expense 1 year 7 months 28 days    
Employee Stock Option [Member]      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Stock options maximum term 10 years    
Amended and Restated 2000 Incentive Plan [Member] | Stock Compensation Plan [Member] | Maximum [Member]      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Number of shares authorized 1,375,000    
Amended and Restated 2000 Incentive Plan [Member] | Restricted Stock [Member]      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Restricted stock awarded 59,000 82,000 34,000
Amended and Restated 2000 Incentive Plan [Member] | Restricted Stock [Member] | Performance Vested Restricted Stock [Member] | Officer [Member]      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Restricted stock awarded 30,000 43,000 15,000
Share-based compensation vesting percentage 100.00%    
Vesting period 3 years    
Amended and Restated 2000 Incentive Plan [Member] | Restricted Stock [Member] | Time Vested Restricted Stock [Member] | Officers and Key Employees [Member]      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Restricted stock awarded 22,000 31,000 12,000
Share-based compensation vesting percentage 33.33%    
Vesting period 3 years    
Amended and Restated 2000 Incentive Plan [Member] | Restricted Stock [Member] | Time Vested Restricted Stock [Member] | Director [Member]      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Restricted stock awarded 7,000 8,000 7,000
Share-based compensation vesting percentage 100.00%    
Vesting period 1 year    
Amended and Restated 2000 Incentive Plan [Member] | Restricted Stock [Member] | Maximum [Member]      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Number of shares authorized 467,000    
Amended and Restated 2000 Incentive Plan [Member] | Employee Stock Option [Member]      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Stock option awards granted 0    
Employee Stock Purchase Plan [Member]      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Stock based compensation expense $ 0 $ 6 $ 44
Income tax benefit to stock based compensation $ 0 $ 2 $ 16
Maximum discount on purchase price of common stock percentage on fair market value 15.00%    
Issue of treasury stock to the ESPP for the offering periods 7,000 15,000 16,000
Increase in capital in excess of par value for the income tax benefit realized from disqualifying dispositions $ 0 $ 0 $ 1
Common stock may be purchased 200