Annual report pursuant to Section 13 and 15(d)

Stock Compensation Plans - Additional Information (Detail)

v3.7.0.1
Stock Compensation Plans - Additional Information (Detail) - USD ($)
$ in Thousands
12 Months Ended
Mar. 31, 2017
Mar. 31, 2016
Mar. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Cash proceeds from the exercise of stock options $ 137 $ 97 $ 47
Total intrinsic value of the stock options exercised 113 71 32
Unrecognized stock-based compensation expense $ 1,776    
Weighted average period for recognize expense 1 year 9 months    
Options, stock awards and performance awards available for future grants 311,000    
Stock Compensation Plan [Member]      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Stock based compensation expense $ 621 653 598
Income tax benefit to stock based compensation 219 230 210
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 $ (19) $ 5 $ 197
Restricted Stock [Member]      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Restricted stock awarded 82,000 34,000 30,000
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 82,000 34,000 30,000
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 43,000 15,000 12,000
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 31,000 12,000 11,000
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 8,000 7,000 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 $ 6 $ 44 $ 55
Income tax benefit to stock based compensation $ 2 $ 16 $ 19
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 15,000 16,000 12,000
Increase in capital in excess of par value for the income tax benefit realized upon exercise of stock options and vesting of restricted $ 0 $ 1 $ 3