Condensed Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Income Statement [Abstract]
Revenues	$ 402,925	$ 414,371
Operating expenses:
Direct salaries and related costs	261,728	275,072
General and administrative	104,680	102,440
Depreciation, net	13,897	14,836
Amortization of intangibles	4,286	4,213
Impairment of long-lived assets	1,582	3,526
Total operating expenses	386,173	400,087
Income from operations	16,752	14,284
Other income (expense):
Interest income	185	171
Interest (expense)	(1,178)	(1,206)
Other income (expense), net	610	155
Total other income (expense), net	(383)	(880)
Income before income taxes	16,369	13,404
Income taxes	4,682	2,456
Net income	$ 11,687	$ 10,948
Net income per common share:
Basic	$ 0.28	$ 0.26
Diluted	$ 0.28	$ 0.26
Weighted average common shares outstanding:
Basic	42,169	41,939
Diluted	42,299	42,232