Commitments and Contingencies Deferred Acquisition Payments (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2011
Business Acquisition, Contingent Consideration [Line Items]
Deferred acquisition payments	$ 120.6
Redeemable noncontrolling interests and call options with affiliates	129.0	[1]
Total contingent acquisition payments	249.6
Less: cash compensation expense included above	4.3
Total	245.3
Contingent acquisition obligation payments for redeemable noncontrolling interests	4.6
2012
Business Acquisition, Contingent Consideration [Line Items]
Deferred acquisition payments	40.7
Redeemable noncontrolling interests and call options with affiliates	15.6	[1]
Total contingent acquisition payments	56.3
Less: cash compensation expense included above	3.6
Total	52.7
2013
Business Acquisition, Contingent Consideration [Line Items]
Deferred acquisition payments	13.6
Redeemable noncontrolling interests and call options with affiliates	53.4	[1]
Total contingent acquisition payments	67.0
Less: cash compensation expense included above	0.3
Total	66.7
2014
Business Acquisition, Contingent Consideration [Line Items]
Deferred acquisition payments	14.5
Redeemable noncontrolling interests and call options with affiliates	22.8	[1]
Total contingent acquisition payments	37.3
Less: cash compensation expense included above	0.2
Total	37.1
2015
Business Acquisition, Contingent Consideration [Line Items]
Deferred acquisition payments	5.9
Redeemable noncontrolling interests and call options with affiliates	26.5	[1]
Total contingent acquisition payments	32.4
Less: cash compensation expense included above	0.2
Total	32.2
2016
Business Acquisition, Contingent Consideration [Line Items]
Deferred acquisition payments	29.3
Redeemable noncontrolling interests and call options with affiliates	4.0	[1]
Total contingent acquisition payments	33.3
Less: cash compensation expense included above	0
Total	33.3
Thereafter
Business Acquisition, Contingent Consideration [Line Items]
Deferred acquisition payments	16.6
Redeemable noncontrolling interests and call options with affiliates	6.7	[1]
Total contingent acquisition payments	23.3
Less: cash compensation expense included above	0
Total	$ 23.3

[1] We have entered into certain acquisitions that contain both redeemable noncontrolling interests and call options with similar terms and conditions. In such instances, we have included the related estimated contingent acquisition obligation in the period when the earliest related option is exercisable. We have certain redeemable noncontrolling interests that are exercisable at the discretion of the noncontrolling equity owners as of December 31, 2011. These estimated acquisition payments of $4.6 have been included within the total payments expected to be made in 2012 in the table. If not made in 2012, they will continue to carry forward into 2013 or beyond until they are exercised or expire. Redeemable noncontrolling interests are included in the table at current exercise price payable in cash, not at applicable redemption value in accordance with the authoritative guidance for classification and measurement of redeemable securities.