Intangible Assets (Details) (USD $)	3 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Sep. 30, 2012
Gross carrying amount and accumulated amortization of intangible assets
Gross Carrying Amount	$ 305,616,000		$ 305,616,000
Accumulated Amortization	166,641,000		161,705,000
Amortization expense related to intangible assets	4,900,000	5,500,000
CCP Contracts
Gross carrying amount and accumulated amortization of intangible assets
Estimated useful lives	20 years
Gross Carrying Amount	106,400,000		106,400,000
Accumulated Amortization	54,709,000		53,379,000
Customer Relationships
Gross carrying amount and accumulated amortization of intangible assets
Gross Carrying Amount	72,464,000		72,464,000
Accumulated Amortization	39,680,000		38,382,000
Customer Relationships | Minimum
Gross carrying amount and accumulated amortization of intangible assets
Estimated useful lives	5 years
Customer Relationships | Maximum
Gross carrying amount and accumulated amortization of intangible assets
Estimated useful lives	15 years
Trade Names
Gross carrying amount and accumulated amortization of intangible assets
Gross Carrying Amount	67,890,000		67,890,000
Accumulated Amortization	27,979,000		27,105,000
Trade Names | Minimum
Gross carrying amount and accumulated amortization of intangible assets
Estimated useful lives	5 years
Trade Names | Maximum
Gross carrying amount and accumulated amortization of intangible assets
Estimated useful lives	20 years
Patents And Patented Technologies
Gross carrying amount and accumulated amortization of intangible assets
Gross Carrying Amount	55,102,000		55,102,000
Accumulated Amortization	43,009,000		41,661,000
Patents And Patented Technologies | Minimum
Gross carrying amount and accumulated amortization of intangible assets
Estimated useful lives	4 years
Patents And Patented Technologies | Maximum
Gross carrying amount and accumulated amortization of intangible assets
Estimated useful lives	19 years
Other Intangible Assets
Gross carrying amount and accumulated amortization of intangible assets
Gross Carrying Amount	3,760,000		3,760,000
Accumulated Amortization	$ 1,264,000		$ 1,178,000
Other Intangible Assets | Minimum
Gross carrying amount and accumulated amortization of intangible assets
Estimated useful lives	3 years
Other Intangible Assets | Maximum
Gross carrying amount and accumulated amortization of intangible assets
Estimated useful lives	17 years