Goodwill and Intangible Assets - Intangible Assets (Details) - USD ($)	6 Months Ended
	Mar. 31, 2017	Sep. 30, 2016
Amortizable intangible assets:
Gross Carrying Value	$ 266,188,000	$ 266,188,000
Accumulated Amortization	(116,213,000)	(105,131,000)
Net Carrying Value	149,975,000	161,057,000
Indefinite-lived Intangible Assets [Line Items]
Goodwill, period increase (decrease)	0
Intangible Assets, Net (Excluding Goodwill) [Abstract]
Gross Carrying Value	360,068,000	360,068,000
Net Carrying Value	243,855,000	254,937,000
Trade names
Indefinite-lived Intangible Assets [Line Items]
Gross carrying value/net carrying value	93,880,000	93,880,000
Customer relationships
Amortizable intangible assets:
Gross Carrying Value	249,245,000	249,245,000
Accumulated Amortization	(107,759,000)	(97,484,000)
Net Carrying Value	$ 141,486,000	151,761,000
Customer relationships | Weighted Average Useful Life (Years)
Amortizable intangible assets:
Weighted Average Useful Life (Years)	12 years
Other
Amortizable intangible assets:
Gross Carrying Value	$ 16,943,000	16,943,000
Accumulated Amortization	(8,454,000)	(7,647,000)
Net Carrying Value	$ 8,489,000	$ 9,296,000
Other | Weighted Average Useful Life (Years)
Amortizable intangible assets:
Weighted Average Useful Life (Years)	7 years