Percentage of voting equity interests acquired in the business combination.

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The amount of acquisition cost of a business combination allocated to an identifiable intangible asset that will be amortized.

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Amount of goodwill arising from a business combination, which is the excess of the cost of the acquired entity over the amounts assigned to assets acquired and liabilities assumed.

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The amount of goodwill arising from a business combination that is expected to be deductible for tax purposes.

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The amount of acquisition cost of a business combination allocated to an identifiable intangible asset that will not be amortized. Does not include goodwill.

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Amount of acquisition cost of a business combination allocated to assets, excluding financial assets and goodwill, lacking physical substance.

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This element represents acquisition-related costs incurred to effect a business combination which costs have been expensed during the period. Such costs include finder's fees; advisory, legal, accounting, valuation, and other professional or consulting fees; general administrative costs, including the costs of maintaining an internal acquisitions department; and may include costs of registering and issuing debt and equity securities.

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Useful life of finite-lived intangible assets, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Gain (loss) from sale or disposal of an organization or integrated set of activities (for example, but not limited to, a partnership or corporation) engaged in providing a product or service in a commercial, industrial, or professional environment.

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Change in the carrying value of goodwill. The change could be the result of new goodwill acquired, goodwill impairment, if any, goodwill written off related to the sale of a business or other adjustments to goodwill.

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The number of businesses acquired by the entity during the period.

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The cash inflow associated with the amount received from the sale of a portion of the company's business, for example a segment, division, branch or other business, during the period.

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Acquisitions and Divestitures - Additional Information (Detail) (USD $)	1 Months Ended	3 Months Ended			9 Months Ended
	Jul. 31, 2012	Sep. 30, 2012 Entity	Jun. 30, 2012 Entity	Mar. 31, 2012 Entity	Sep. 30, 2012 Entity	Sep. 30, 2011
Significant Acquisitions and Disposals [Line Items]
Number of acquisitions completed		12	8	11	31
Goodwill		$ 87,410,000			$ 87,410,000
Tax deductible goodwill amount		56,700,000			56,700,000
Intangibles		98,706,000			98,706,000
Indefinite lived intangible assets, permits		23,400,000			23,400,000
Acquisition expenses					6,200,000	14,400,000
Proceeds from sale of business and other assets					764,000	2,371,000
Loss on sale of business	5,631,000				4,867,000	323,000
United States
Significant Acquisitions and Disposals [Line Items]
Number of acquisitions completed					12
Goodwill period increase decrease					55,800,000
Romania
Significant Acquisitions and Disposals [Line Items]
Number of acquisitions completed					2
Spain
Significant Acquisitions and Disposals [Line Items]
Number of acquisitions completed					6
Japan
Significant Acquisitions and Disposals [Line Items]
Number of acquisitions completed					1
Brazil
Significant Acquisitions and Disposals [Line Items]
Number of acquisitions completed					1
Business acquisition, ownership percentage acquired		100.00%		100.00%	100.00%
United Kingdom
Significant Acquisitions and Disposals [Line Items]
Number of acquisitions completed					3
Argentina
Significant Acquisitions and Disposals [Line Items]
Number of acquisitions completed					1
Chile
Significant Acquisitions and Disposals [Line Items]
Number of acquisitions completed					2
Business acquisition, ownership percentage acquired			90.00%
Portugal
Significant Acquisitions and Disposals [Line Items]
Number of acquisitions completed					1
Mexico
Significant Acquisitions and Disposals [Line Items]
Number of acquisitions completed					2
International
Significant Acquisitions and Disposals [Line Items]
Goodwill period increase decrease					31,600,000
Customer relationships
Significant Acquisitions and Disposals [Line Items]
Intangibles assets, amortizable		72,500,000			72,500,000
Customer relationships \| Minimum
Significant Acquisitions and Disposals [Line Items]
Finite lived intangible assets useful life					15 years
Customer relationships \| Maximum
Significant Acquisitions and Disposals [Line Items]
Finite lived intangible assets useful life					40 years
Tradenames
Significant Acquisitions and Disposals [Line Items]
Intangibles assets, amortizable		2,700,000			2,700,000
Finite lived intangible assets useful life					15 years
Tradenames \| Minimum
Significant Acquisitions and Disposals [Line Items]
Finite lived intangible assets useful life					15 years
Tradenames \| Maximum
Significant Acquisitions and Disposals [Line Items]
Finite lived intangible assets useful life					40 years
Other Intangible Assets
Significant Acquisitions and Disposals [Line Items]
Intangibles assets, amortizable		$ 100,000			$ 100,000
Finite lived intangible assets useful life					10 years
Regulated waste management services \| United States
Significant Acquisitions and Disposals [Line Items]
Number of acquisitions completed		3	1	2
Business acquisition, ownership percentage acquired		100.00%		100.00%	100.00%
Regulated waste management services \| Romania
Significant Acquisitions and Disposals [Line Items]
Number of acquisitions completed		1		1
Business acquisition, ownership percentage acquired				100.00%
Regulated waste management services \| Spain
Significant Acquisitions and Disposals [Line Items]
Number of acquisitions completed			3	3
Business acquisition, ownership percentage acquired			100.00%	100.00%
Regulated waste management services \| Japan
Significant Acquisitions and Disposals [Line Items]
Number of acquisitions completed				1
Regulated waste management services \| Brazil
Significant Acquisitions and Disposals [Line Items]
Number of acquisitions completed		1
Business acquisition, ownership percentage acquired		100.00%			100.00%	82.50%
Regulated waste management services \| United Kingdom
Significant Acquisitions and Disposals [Line Items]
Number of acquisitions completed		2
Business acquisition, ownership percentage acquired		100.00%			100.00%
Regulated waste management services \| Argentina
Significant Acquisitions and Disposals [Line Items]
Number of acquisitions completed			1
Regulated waste management services \| Chile
Significant Acquisitions and Disposals [Line Items]
Number of acquisitions completed		2
Business acquisition, ownership percentage acquired		70.00%			70.00%
Regulated waste management services \| Portugal
Significant Acquisitions and Disposals [Line Items]
Number of acquisitions completed		1
Regulated waste management services \| Mexico
Significant Acquisitions and Disposals [Line Items]
Number of acquisitions completed		2
Business acquisition, ownership percentage acquired		100.00%			100.00%
Patient communication and compliance businesses \| United States
Significant Acquisitions and Disposals [Line Items]
Number of acquisitions completed			2	4
Patient communication and compliance businesses \| United Kingdom
Significant Acquisitions and Disposals [Line Items]
Number of acquisitions completed			1