Quarterly report pursuant to Section 13 or 15(d)

Basis of Presentation and Significant Accounting Policies - Additional Information (Detail)

v2.4.0.8
Basis of Presentation and Significant Accounting Policies - Additional Information (Detail) (USD $)
 1 Months Ended 3 Months Ended 6 Months Ended
Dec. 31, 2005
May 31, 2013
CompensationPlan
May 31, 2012
May 31, 2013
Deliverables
CompensationPlan
May 30, 2012
Directors
May 31, 2012
Nov. 30, 2012
Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits [Line Items]              
Number of deliverables for revenue recognized       2      
Deferred revenue recognition period       12 months      
Valuation allowance   $ 10,885,000   $ 10,885,000     $ 10,947,000
U.S. Income tax expense   0 1,700,000 0   1,700,000  
Amount transferred to reserve against losses     1,700,000     1,700,000  
Foreign income tax expense   43,000 25,000 85,000   82,000  
Minimum percentage probability of realized tax benefit on settlement       50.00%      
Provision for interest or penalties related to uncertain tax positions   0 0 0   0  
Impairment on long lived assets   0 0 0   0  
Abandonment of patents   378,837   378,837      
Number of employee stock based compensation plan   3   3      
Stock option compensation expense   72,000 760,000 162,000   1,019,000  
Number of individuals nominated directors         6    
Immediate vesting of the options included in stock compensation expense       161,841   1,019,339  
Payment Warranty 50,000            
Increased payment warranty       75,000      
Additional payment warranty       10,000      
Reserves recorded under programs   15,066   15,066     14,485
Chief Executive Officer [Member]
              
Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits [Line Items]              
Immediate vesting of the options included in stock compensation expense     $ 700,000        
Minimum [Member]
              
Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits [Line Items]              
Contracted storage periods       1 year      
Maximum [Member]
              
Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits [Line Items]              
Contracted storage periods       21 years