Intangible Assets - Gross Carrying Amounts and Accumulated Amortization (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Mar. 31, 2017	Mar. 31, 2016	Sep. 30, 2016
Gross carrying amount and accumulated amortization of intangible assets
Total Gross Carrying Amount	$ 505,160		$ 505,160		$ 507,967
Accumulated Amortization	198,856		198,856		188,805
Amortization expense related to intangible assets	6,400	$ 4,800	12,700	$ 9,400
Trade names
Gross carrying amount and accumulated amortization of intangible assets
Gross Carrying Amount	62,574		$ 62,574		63,245
Intellectual property
Gross carrying amount and accumulated amortization of intangible assets
Estimated useful lives			20 years
Gross Carrying Amount	10,026		$ 10,026		10,102
Accumulated Amortization	654		654
Contracts
Gross carrying amount and accumulated amortization of intangible assets
Gross Carrying Amount	125,130		125,130		127,520
Accumulated Amortization	76,697		76,697		76,029
Customer relationships
Gross carrying amount and accumulated amortization of intangible assets
Gross Carrying Amount	226,779		226,779		227,909
Accumulated Amortization	73,912		$ 73,912		67,493
Trade names
Gross carrying amount and accumulated amortization of intangible assets
Estimated useful lives			20 years
Gross Carrying Amount	66,755		$ 66,755		66,755
Accumulated Amortization	41,413		41,413		39,744
Patents and Patented Technologies
Gross carrying amount and accumulated amortization of intangible assets
Gross Carrying Amount	6,347		6,347		5,401
Accumulated Amortization	3,180		3,180		2,875
Other
Gross carrying amount and accumulated amortization of intangible assets
Gross Carrying Amount	7,549		7,549		7,035
Accumulated Amortization	$ 3,000		$ 3,000		$ 2,664
Minimum | Contracts
Gross carrying amount and accumulated amortization of intangible assets
Estimated useful lives			15 years
Minimum | Customer relationships
Gross carrying amount and accumulated amortization of intangible assets
Estimated useful lives			5 years
Minimum | Patents and Patented Technologies
Gross carrying amount and accumulated amortization of intangible assets
Estimated useful lives			7 years
Minimum | Other
Gross carrying amount and accumulated amortization of intangible assets
Estimated useful lives			5 years
Maximum | Contracts
Gross carrying amount and accumulated amortization of intangible assets
Estimated useful lives			20 years
Maximum | Customer relationships
Gross carrying amount and accumulated amortization of intangible assets
Estimated useful lives			20 years
Maximum | Patents and Patented Technologies
Gross carrying amount and accumulated amortization of intangible assets
Estimated useful lives			19 years
Maximum | Other
Gross carrying amount and accumulated amortization of intangible assets
Estimated useful lives			17 years