v2.4.0.8
Fair Value Measurement (Details) (USD $)
Sep. 30, 2013
NESA
Nov. 02, 2012
NESA
Sep. 30, 2013
Jacobs Trading, LLC
Sep. 30, 2012
Jacobs Trading, LLC
Oct. 02, 2011
Jacobs Trading, LLC
Sep. 30, 2013
Recurring basis
Level 1
Sep. 30, 2012
Recurring basis
Level 1
Sep. 30, 2013
Recurring basis
Level 2
Sep. 30, 2012
Recurring basis
Level 2
Sep. 30, 2013
Recurring basis
Level 3
NESA
Sep. 30, 2012
Recurring basis
Level 3
Jacobs Trading, LLC
Fair value measurement                      
Assets, fair value           $ 0 $ 0 $ 0 $ 0    
Liabilities, fair value           0 0 0 0    
Estimated fair value of earn-out $ 18,300,000 $ 18,000,000 $ 0 $ 14,500,000 $ 8,300,000         $ 18,390,000 $ 14,511,000