Intangible Assets, Goodwill and Acquisitions - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Finite Lived Intangible Assets [Line Items]
Amortization of intangible assets	$ 29,247	$ 31,250	$ 89,611	$ 94,800
Minimum | Customer Relationships
Finite Lived Intangible Assets [Line Items]
Estimated useful life of intangible assets			6 years
Minimum | Trademarks
Finite Lived Intangible Assets [Line Items]
Estimated useful life of intangible assets			4 years
Maximum | Customer Relationships
Finite Lived Intangible Assets [Line Items]
Estimated useful life of intangible assets			21 years
Maximum | Trademarks
Finite Lived Intangible Assets [Line Items]
Estimated useful life of intangible assets			12 years