Cash Paid for Acquisitions (Details) (USD $) In Millions	9 Months Ended
	Sep. 30, 2011		Sep. 30, 2010
Total cost of investment	$ 120.7	[1]	$ 88.8	[1]
Total cash paid for acquisitions	120.9		91.8
Less: net cash acquired	(5.9)		(5.4)
Acquisition-related payments	(70.4)		(25.8)
Acquisitions, including deferred payments, net of cash acquired	(50.3)		(63.0)
Cash paid for current year acquisitions
Total cost of investment	23.0		47.1
Cash paid for prior year acquisitions
Total cost of investment	103.6		47.1
Operating expense	$ 0.2	[2]	$ 3.0	[2]

[1] Of the total cash paid, $70.4 and $25.8 for the nine months ended September 30, 2011 and 2010, respectively, are classified under the financing section of the unaudited Consolidated Statements of Cash Flows within acquisition-related payments. These transactions relate to increases in our ownership interests in our consolidated subsidiaries as well as deferred payments for acquisitions that closed on or after January 1, 2009. Of the total cash paid, $50.3 and $63.0 for the nine months ended September 30, 2011 and 2010, respectively, are classified under the investing section of the unaudited Consolidated Statements of Cash Flows within acquisitions, including deferred payments, net of cash acquired. These transactions relate to initial payments for new transactions and deferred payments for acquisitions that closed prior to January 1, 2009.

[2] Represents cash payments made that were either in excess of the contractual value or contingent upon the future employment of the former owners of acquired companies.