Derivative Financial Instruments - Balance Sheet (Details) - USD ($)
$ in Thousands
Dec. 31, 2015
Sep. 30, 2015
Dec. 31, 2014
Derivative [Line Items]      
Net fair value $ 3,705 $ 3,705 $ 1,660
Foreign Exchange Contract      
Derivative [Line Items]      
Net fair value 3,705   1,660
Foreign Exchange Contract | Prepaid Expenses      
Derivative [Line Items]      
Net fair value 3,705   1,660
Foreign Exchange Contract | Other Noncurrent Assets      
Derivative [Line Items]      
Net fair value $ 0   $ 0