Quarterly report pursuant to Section 13 or 15(d)

Stock-Based Compensation - Additional Information (Detail)

v2.4.0.8
Stock-Based Compensation - Additional Information (Detail) (USD $)
In Thousands, unless otherwise specified
3 Months Ended 6 Months Ended
Sep. 30, 2013
Sep. 30, 2012
Sep. 30, 2013
Sep. 30, 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Number of shares authorized 1,375   1,375  
Restricted Stock Units (RSUs) [Member] | Maximum [Member]
       
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Number of shares authorized 250   250  
Stock Option [Member]
       
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Stock options maximum term     10 years  
Stock option awards granted 0 0 0 49
Share-based compensation vesting percentage     33.33%  
Stock vesting period     3 years  
Restricted Stock [Member]
       
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Restricted stock awards 0 0 32 26
Performance Vested Restricted Stock [Member] | Officer [Member]
       
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Share-based compensation vesting percentage     100.00%  
Restricted stock awards     14 18
Period of performance metrics     3 years  
Time Vested Restricted Stock [Member] | Officers and Key Employees [Member]
       
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Share-based compensation vesting percentage     33.33%  
Stock vesting period     3 years  
Restricted stock awards     12  
Time Vested Restricted Stock [Member] | Director [Member]
       
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Share-based compensation vesting percentage     100.00%  
Restricted stock awards     6 8
Stock Compensation Plan [Member]
       
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Stock-based compensation expense $ 134 $ 136 $ 314 $ 292
Income tax benefit to stock-based compensation 47 48 110 103
Employee Stock Purchase Plan [Member]
       
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Stock-based compensation expense 13 11 28 26
Income tax benefit to stock-based compensation $ 4 $ 4 $ 9 $ 8
Discounted purchase price of common stock percentage on fair market value     85.00%  
Shares approved for purchase under ESPP 200   200