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Acquisitions Of Businesses (Details) $ in Thousands					3 Months Ended	12 Months Ended
	Mar. 01, 2017 Company	Jan. 04, 2017 Company	Apr. 15, 2016 USD ($) Company	Apr. 01, 2016 Company	Mar. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)
Business Acquisition [Line Items]
Goodwill					$ 1,010,399	$ 979,628
Number of businesses acquired | Company	1	1	1	1
Q1 2017 Acquisitions [Member]
Business Acquisition [Line Items]
Purchase price					84,800
Working capital acquired					9,600
Other net assets					300
Goodwill					28,700
Identifiable intangible assets					$ 46,200
Ardent [Member]
Business Acquisition [Line Items]
Business acquisition, percentage of voting interests acquired			100.00%
Purchase price			$ 201,400
Working capital acquired			34,100
Other net assets			3,900
Goodwill			121,900
Identifiable intangible assets			41,500
Acquired goodwill, tax deductible amount			$ 99,700
Intangible amortization period						13 years 6 months

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The amount of acquisition cost of a business combination allocated to other net assets.

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The amount of acquisition cost of a business combination allocated to working capital.

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Percentage of voting equity interests acquired at the acquisition date in the business combination.

+ References

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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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Amount of intangible assets, excluding goodwill, acquired at the acquisition date.

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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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Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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

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The cash outflow associated with the acquisition of business during the period. The cash portion only of the acquisition price.

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