Goodwill and Other Intangible Assets - Schedule of Other Intangible Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Sep. 30, 2017
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangibles, Accumulated Amortization	$ (547,281)	$ (506,825)
Intangible Assets
Gross Carrying Amount	3,372,316	3,340,106
Net Carrying Amount	2,825,035	2,833,281
Trade names
Indefinite-lived intangibles
Indefinite-lived intangibles	685,072	685,088
Customer relationships
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangibles, Gross Carrying Amount	2,360,751	2,329,665
Finite-lived intangibles, Accumulated Amortization	(442,360)	(408,636)
Finite-lived intangibles, Net Carrying Amount	1,918,391	1,921,029
Trade names and other
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangibles, Gross Carrying Amount	326,493	325,353
Finite-lived intangibles, Accumulated Amortization	(104,921)	(98,189)
Finite-lived intangibles, Net Carrying Amount	$ 221,572	$ 227,164