Description of Business and Basis of Presentation (Details) $ in Thousands	12 Months Ended
	Sep. 30, 2017 USD ($) revenue_category	Sep. 30, 2016 USD ($)	Sep. 30, 2015 USD ($)
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Revenue, Net	$ 1,164,039	$ 1,140,533	$ 1,255,242
Number of Cost of Revenue Categories | revenue_category	3
Out of Period Correction [Member] | Restatement Adjustment [Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Revenue, Net			$ 6,400