Condensed Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Income Statement [Abstract]
Revenues	$ 411,166	$ 402,925
Operating expenses:
Direct salaries and related costs	266,945	261,728
General and administrative	103,247	104,680
Depreciation, net	12,461	13,897
Amortization of intangibles	4,119	4,286
Impairment of long-lived assets		1,582
Total operating expenses	386,772	386,173
Income from operations	24,394	16,752
Other income (expense):
Interest income	263	185
Interest (expense)	(720)	(1,178)
Other income (expense), net	(4,793)	610
Total other income (expense), net	(5,250)	(383)
Income before income taxes	19,144	16,369
Income taxes	5,226	4,682
Net income	$ 13,918	$ 11,687
Net income per common share:
Basic	$ 0.34	$ 0.28
Diluted	$ 0.34	$ 0.28
Weighted average common shares outstanding:
Basic	41,132	42,169
Diluted	41,334	42,299