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Business and Organization (Detail)	9 Months Ended	12 Months Ended
	Sep. 30, 2017 Segment Acquisition	Dec. 31, 2016 Acquisition
Organization And Description Of Business [Line Items]
Number of reportable segments | Segment	2
Acquisitions 2017, other than Stronghold
Organization And Description Of Business [Line Items]
Number of business acquisitions	2
Acquisitions 2016
Organization And Description Of Business [Line Items]
Number of business acquisitions		5

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- Definition

Organization And Description Of Business [Line Items]

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

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Number of segments reported by the entity. A reportable segment is a component of an entity for which there is an accounting requirement to report separate financial information on that component in the entity's financial statements.

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