CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Net service revenues	$ 1,063,228	$ 1,028,383	$ 2,086,912	$ 2,043,827
Direct costs of services, consisting of payroll, payroll taxes, insurance costs and reimbursable expenses	631,120	613,080	1,244,514	1,226,441
Gross margin	432,108	415,303	842,398	817,386
Selling, general and administrative expenses	331,314	343,264	652,099	665,282
Amortization of intangible assets	434	52	867	87
Interest income, net	(236)	(285)	(540)	(519)
Income before income taxes	100,596	72,272	189,972	152,536
Provision for income taxes	37,507	26,943	71,020	58,873
Net income	63,089	45,329	118,952	93,663
Net income available to common stockholders-diluted	$ 63,088	$ 45,101	$ 118,948	$ 93,171
Net income per share (Note I):
Basic	$ 0.46	$ 0.33	$ 0.87	$ 0.67
Diluted	$ 0.46	$ 0.32	$ 0.86	$ 0.67
Shares:
Basic	136,385	138,588	136,845	138,986
Diluted	137,659	139,739	138,024	140,036
Cash dividends declared per share	$ 0.16	$ 0.15	$ 0.32	$ 0.30