Condensed Consolidated Statement of Income (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Operating revenues	$ 495.2	$ 475.9
Out-of-pocket reimbursements	187.2	177.3
Total revenues	682.4	653.2
Costs and expenses	574.6	559.1
Depreciation and amortization	33.2	34.0
Income from operations	74.6	60.1
Interest expense	(9.6)	(11.7)
Other income (expense), net	73.2	29.7
Equity in earnings of unconsolidated affiliates	5.6	5.3
Income before income taxes	143.8	83.4
Income taxes	50.6	28.1
Net income	$ 93.2	$ 55.3
Average common shares outstanding (in shares)	44.3	44.5
Average diluted shares outstanding (in shares)	45.6	45.2
Basic earnings per share (in dollars per share)	$ 2.10	$ 1.24
Diluted earnings per share (in dollars per share)	$ 2.04	$ 1.22
Cash dividends per share of common stock (in dollars per share)	$ 0.3	$ 0.4