v2.4.0.8
Fair Value Measurement (Details 2) (Contingent consideration, USD $)
12 Months Ended
Sep. 30, 2013
Sep. 30, 2012
Changes in liabilities measured at fair value for which the Company has used Level 3 inputs to determine fair value    
Balance at the beginning of the period $ 14,511,000 $ 10,151,000
Acquisition contingent consideration 18,050,000 8,185,000
Settlements (19,608,000) (3,162,000)
Increase (decrease) of contingent consideration 5,437,000 (663,000)
Balance at the end of the period 18,390,000 14,511,000
Jacobs Trading, LLC
   
Changes in liabilities measured at fair value for which the Company has used Level 3 inputs to determine fair value    
Increase (decrease) of contingent consideration 5,097,000  
NESA
   
Changes in liabilities measured at fair value for which the Company has used Level 3 inputs to determine fair value    
Increase (decrease) of contingent consideration $ 340,000  
Level 3 | Income approach | Minimum
   
Changes in liabilities measured at fair value for which the Company has used Level 3 inputs to determine fair value    
Discount rate (as a percent) 2.00%  
Level 3 | Income approach | Maximum
   
Changes in liabilities measured at fair value for which the Company has used Level 3 inputs to determine fair value    
Discount rate (as a percent) 9.70%