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 $)
 0 Months Ended 1 Months Ended 3 Months Ended 6 Months Ended
Feb. 02, 2012
Dec. 31, 2005
May 31, 2014
CompensationPlan
May 31, 2013
May 31, 2014
Deliverables
CompensationPlan
May 31, 2013
Nov. 30, 2013
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     $ 10,443,000   $ 10,443,000   $ 10,852,000
U.S. Income tax expense     0   0    
Foreign income tax expense     25,000 43,000 73,000 85,000  
Minimum percentage probability of realized tax benefit on settlement         50.00%    
Provisions for interest or penalties related to uncertain tax positions     0 0 0 0  
Uncertain tax provisions     0 0 0 0  
Impairment on long lived assets     0 0 0 0  
Writing off abandoned patent and trademarks     25,649 378,837 25,649 378,837  
Number of employee stock based compensation plan     3   3    
Stock option compensation expense     56,000 72,000 208,000 162,000  
Unrealized holding gain and loss     7,354 2,010 22,879 2,390  
Payment warranty   50,000          
Increased payment warranty 75,000            
Additional payment warranty 10,000            
Reserves recorded under programs     $ 16,162   $ 16,162   $ 15,608
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