Quarterly report pursuant to Section 13 or 15(d)

Stock-Based Compensation - Additional Information (Detail)

v3.10.0.1
Stock-Based Compensation - Additional Information (Detail) - USD ($)
3 Months Ended 6 Months Ended
Sep. 30, 2018
Sep. 30, 2017
Sep. 30, 2018
Sep. 30, 2017
Stock Compensation Plan [Member]        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Stock based compensation expense $ 274,000 $ 216,000 $ 534,000 $ 149,000
Income tax benefit to stock based compensation $ 60,000 $ 76,000 $ 118,000 $ 53,000
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   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 0 0 53,000 59,000
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     27,000 30,000
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     20,000 22,000
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     6,000 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   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 0 0 0
Employee Stock Purchase Plan [Member]        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Stock based compensation expense $ 0 $ 0 $ 0 $ 0
Maximum discount on purchase price of common stock percentage on fair market value     15.00%  
Common stock may be purchased 200   200