CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Net service revenues	$ 1,075,119	$ 1,033,173	$ 3,162,031	$ 3,077,000
Direct costs of services, consisting of payroll, payroll taxes, insurance costs and reimbursable expenses	637,641	617,924	1,882,155	1,844,365
Gross margin	437,478	415,249	1,279,876	1,232,635
Selling, general and administrative expenses	333,565	321,030	985,664	986,312
Amortization of intangible assets	433	100	1,300	187
Interest income, net	(233)	(348)	(773)	(867)
Income before income taxes	103,713	94,467	293,685	247,003
Provision for income taxes	37,355	36,807	108,375	95,680
Net income	66,358	57,660	185,310	151,323
Net income available to common stockholders-diluted	$ 66,358	$ 57,383	$ 185,307	$ 150,551
Net income per share (Note J):
Basic	$ 0.49	$ 0.42	$ 1.36	$ 1.09
Diluted	$ 0.48	$ 0.41	$ 1.35	$ 1.08
Shares:
Basic	135,727	137,918	136,469	138,627
Diluted	137,241	139,141	137,759	139,735
Cash dividends declared per share	$ 0.16	$ 0.15	$ 0.48	$ 0.45