v2.4.0.8
Property and Equipment Net (Detail) (USD $)
In Thousands, unless otherwise specified
 9 Months Ended
Jun. 30, 2013
Sep. 30, 2012
Property, Plant and Equipment [Line Items]    
Property and equipment, gross $ 242,086 $ 219,862
Less accumulated depreciation and amortization (140,761) (127,923)
Property and equipment, net 101,325 91,939
Land
    
Property, Plant and Equipment [Line Items]    
Property and equipment, gross 1,456 1,456
Building and building improvements
    
Property, Plant and Equipment [Line Items]    
Depreciable Lives (in years) 35 years  
Property and equipment, gross 13,675 13,675
Leasehold improvements
    
Property, Plant and Equipment [Line Items]    
Property and equipment, gross 48,160 47,185
Leasehold improvements | Minimum
    
Property, Plant and Equipment [Line Items]    
Depreciable Lives (in years) 1 year  
Leasehold improvements | Maximum
    
Property, Plant and Equipment [Line Items]    
Depreciable Lives (in years) 28 years  
Training equipment
    
Property, Plant and Equipment [Line Items]    
Property and equipment, gross 82,703 79,952
Training equipment | Minimum
    
Property, Plant and Equipment [Line Items]    
Depreciable Lives (in years) 3 years  
Training equipment | Maximum
    
Property, Plant and Equipment [Line Items]    
Depreciable Lives (in years) 10 years  
Office and computer equipment
    
Property, Plant and Equipment [Line Items]    
Property and equipment, gross 37,989 39,656
Office and computer equipment | Minimum
    
Property, Plant and Equipment [Line Items]    
Depreciable Lives (in years) 3 years  
Office and computer equipment | Maximum
    
Property, Plant and Equipment [Line Items]    
Depreciable Lives (in years) 10 years  
Software developed for internal use
    
Property, Plant and Equipment [Line Items]    
Property and equipment, gross 10,895 11,048
Software developed for internal use | Minimum
    
Property, Plant and Equipment [Line Items]    
Depreciable Lives (in years) 3 years  
Software developed for internal use | Maximum
    
Property, Plant and Equipment [Line Items]    
Depreciable Lives (in years) 5 years  
Curriculum development
    
Property, Plant and Equipment [Line Items]    
Depreciable Lives (in years) 5 years  
Property and equipment, gross 18,716 18,716
Vehicles
    
Property, Plant and Equipment [Line Items]    
Depreciable Lives (in years) 5 years  
Property and equipment, gross 978 949
Construction in Progress
    
Property, Plant and Equipment [Line Items]    
Property and equipment, gross $ 27,514 $ 7,225