Condensed Consolidated Statements Of Operations (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Condensed Consolidated Statements Of Operations [Abstract]
Net service revenues	$ 1,015,444	$ 880,869
Direct costs of services, consisting of payroll, payroll taxes, insurance costs and reimbursable expenses	613,361	542,780
Gross margin	402,083	338,089
Selling, general and administrative expenses	322,018	293,686
Amortization of intangible assets	35	39
Interest income, net	(234)	(212)
Income before income taxes	80,264	44,576
Provision for income taxes	31,930	17,871
Net income	48,334	26,705
Net income available to common stockholders-diluted	$ 48,070	$ 26,293
Net income per share (Note J):
Basic	$ 0.34	$ 0.18
Diluted	$ 0.34	$ 0.18
Shares:
Basic	139,384	142,653
Diluted	140,443	144,136
Cash dividends declared per share	$ 0.15	$ 0.14