Goodwill and Intangible Assets, Net (Schedule of Change in Carrying Values of Goodwill Assets by Segment) (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
Mar. 31, 2019	Dec. 31, 2018
Goodwill [Line Items]
Goodwill, beginning balance	$ 422,357	$ 422,959
Acquisitions	3,237
Adjustments	(8)	541
Foreign currency translation	(517)	(1,143)
Net goodwill	425,069	422,357
Healthcare [Member]
Goodwill [Line Items]
Goodwill, beginning balance	294,283	294,064
Acquisitions	3,237
Adjustments	(2)	365
Foreign currency translation		(146)
Net goodwill	297,518	294,283
Energy [Member]
Goodwill [Line Items]
Goodwill, beginning balance	80,034	80,109
Adjustments		200
Foreign currency translation	(58)	(275)
Net goodwill	79,976	80,034
Financial Services Advisory and Compliance [Member]
Goodwill [Line Items]
Goodwill, beginning balance	48,040	48,786
Adjustments	(6)	(24)
Foreign currency translation	(459)	(722)
Net goodwill	$ 47,575	$ 48,040

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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