Debt - Iowa Department of Economic Development - Additional Information (Detail) (USD $)
9 Months Ended 0 Months Ended 1 Months Ended 3 Months Ended 9 Months Ended
May 31, 2014
May 31, 2013
Dec. 01, 2009
Iowa Department of Economic Development Loans [Member]
SecurityLoan
May 31, 2014
Iowa Department of Economic Development Loans [Member]
May 31, 2014
Iowa Department of Economic Development Loans [Member]
May 31, 2014
Iowa Department of Economic Development Loans [Member]
Debt Instrument [Line Items]            
Non interest bearing loans     $ 1,000,000      
Number of monthly payments           60 equal monthly payments
Number of non interest bearing loans     2      
Loan period (in years)     5 years      
Potentially forgivable loan amount     1,000,000      
Periodic repayments of loan     16,667      
Repayment of outstanding balance 367,000 150,000     1,000,000  
Forgivable loan amount forgiven       1,000,000    
Loan forgiveness recorded as non-operating income $ 1,000,000     $ 1,000,000