Dispositions and Discontinued Operations (Schedule of Amounts Attributable to Each Category of Discontinued Operations) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Disposal Group Not Discontinued Operation Income Statement Disclosures [Abstract]
Revenues before reimbursements		$ 82,434
Total revenues		86,452
Cost of services including reimbursable expenses		58,487
General and administrative expenses		7,283
Amortization and depreciation expense		1,953
Interest expense		488
Loss from disposition of discontinued operations	$ (672)
Other expense, net		(29)
(Loss) income from discontinued operations before income tax expense	(672)	18,212
Income tax (benefit) expense from discontinued operations	(183)	4,762
(Loss) income from discontinued operations, net of tax	$ (489)	$ 13,450