CONSOLIDATED STATEMENTS OF INCOME (USD $) In Millions, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Revenue	$ 1,704.8	$ 1,358.2	$ 841.8
Operating expenses:
Compensation and related expenses	718.8	594.5	402.6
Selling, general and administrative	350.8	284.6	126.8
Amortization of intangible assets	97.7	60.0	32.9
Depreciation and other amortization	15.0	14.1	12.7
Other operating expenses	36.4	31.0	26.9
Total operating expenses	1,218.7	984.2	601.9
Operating income	486.1	374.0	239.9
Non-operating (income) and expenses:
Investment and other (income) loss	5.0	(22.9)	(24.9)
Income from equity method investments	(72.7)	(77.5)	(31.6)
Investment (income) loss from Affiliate investments in partnerships		4.5	(27.4)
Interest expense	73.8	66.2	64.6
Imputed interest expense and contingent payment arrangements	27.3	24.9	13.5
Total non-operating (income) and expenses	33.4	(4.8)	(5.8)
Income before income taxes	452.7	378.8	245.7
Income taxes	93.1	91.5	32.8
Net income	359.6	287.3	212.9
Net income (non-controlling interests)	(194.7)	(153.1)	(126.7)
Net (income) loss (non-controlling interests in partnerships)		4.4	(26.7)
Net income (controlling interest)	$ 164.9	$ 138.6	$ 59.5
Earnings per share - basic (in dollars per share)	$ 3.18	$ 2.92	$ 1.44
Earnings per share - diluted (in dollars per share)	$ 3.11	$ 2.81	$ 1.38
Average shares outstanding - basic (in shares)	51.8	47.4	41.4
Average shares outstanding - diluted (in shares)	53.0	49.4	43.3