Segment Information (Schedule of Segment Revenues before Reimbursements, Segment Total Revenues and Segment Operating Profit) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Segment Reporting Information [Line Items]
Total revenues before reimbursements	$ 186,129	$ 161,445
Total revenues	202,862	178,068
Total segment operating profit	52,396	45,954
General and administrative expenses	35,167	37,079
Depreciation expense	4,586	4,997
Amortization expense	1,372	1,752
Other operating costs, net	32	983
Long-term compensation expense attributable to client-service employees (including share-based compensation expense)	1,623	1,445
Operating income (loss)	9,616	(302)
Interest and other (income) expense, net	(239)	1,070
Income (loss) from continuing operations before income tax expense	9,855	(1,372)
Healthcare [Member]
Segment Reporting Information [Line Items]
Total revenues before reimbursements	119,003	90,149
Total revenues	126,569	98,712
Total segment operating profit	36,755	20,390
Energy [Member]
Segment Reporting Information [Line Items]
Total revenues before reimbursements	36,249	33,704
Total revenues	43,700	37,637
Total segment operating profit	10,410	10,728
Financial Services Advisory and Compliance [Member]
Segment Reporting Information [Line Items]
Total revenues before reimbursements	30,877	37,592
Total revenues	32,593	41,719
Total segment operating profit	$ 5,231	$ 14,836