Condensed Consolidated Statement of Income (USD $) In Millions, 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
Operating revenues	$ 480.2	$ 464.0	$ 1,460.5	$ 1,405.4
Out-of-pocket reimbursements	171.6	168.0	530.8	512.6
Total revenues	651.8	632.0	1,991.3	1,918.0
Costs and expenses	531.4	544.4	1,657.3	1,643.1
Depreciation and amortization	34.1	40.5	100.4	116.8
Income from operations	86.3	47.1	233.6	158.1
Interest expense	(8.4)	(10.6)	(27.3)	(34.0)
Other income, net	73.4	72.4	175.0	296.3
Equity in earnings of unconsolidated affiliates	3.8	3.1	18.9	9.8
Income before income taxes	155.1	112.0	400.2	430.2
Income taxes	58.2	26.1	131.6	144.1
Net income	$ 96.9	$ 85.9	$ 268.6	$ 286.1
Average common shares outstanding (in shares)	42.9	45.1	43.6	44.9
Average diluted shares outstanding (in shares)	43.5	46.0	44.5	45.6
Basic earnings per share (in dollars per share)	$ 2.26	$ 1.90	$ 6.16	$ 6.38
Diluted earnings per share (in dollars per share)	$ 2.23	$ 1.87	$ 6.03	$ 6.27
Cash dividends per share of common stock (in dollars per share)	$ 0.30	$ 0	$ 0.90	$ 0.40