Contingent Acquisition Obligations (Details) $ in Millions	Dec. 31, 2015 USD ($)
Deferred acquisition payments
Business Acquisition, Contingent Consideration [Line Items]
Future Contingent Acquisition Obligation Due in 2016	$ 53.8
Future Contingent Acquisition Obligation Due in 2017	39.2
Future Contingent Acquisition Obligation Due in 2018	13.1
Future Contingent Acquisition Obligation Due in 2019	13.6
Future Contingent Acquisition Obligation Due in 2020	7.5
Future Contingent Acquisition Obligation Due Thereafter	3.1
Future Contingent Acquisition Obligation Due, Total	130.3
Redeemable noncontrolling interests and call options with affiliates
Business Acquisition, Contingent Consideration [Line Items]
Future Contingent Acquisition Obligation Due in 2016	48.4	[1]
Future Contingent Acquisition Obligation Due in 2017	70.5	[1]
Future Contingent Acquisition Obligation Due in 2018	43.0	[1]
Future Contingent Acquisition Obligation Due in 2019	6.4	[1]
Future Contingent Acquisition Obligation Due in 2020	5.2	[1]
Future Contingent Acquisition Obligation Due Thereafter	11.9	[1]
Future Contingent Acquisition Obligation Due, Total	185.4	[1]
Redeemable at noncontrolling equity owners discretion
Business Acquisition, Contingent Consideration [Line Items]
Future Contingent Acquisition Obligation Due in 2016	31.0
Total contingent acquisition payments
Business Acquisition, Contingent Consideration [Line Items]
Future Contingent Acquisition Obligation Due in 2016	102.2
Future Contingent Acquisition Obligation Due in 2017	109.7
Future Contingent Acquisition Obligation Due in 2018	56.1
Future Contingent Acquisition Obligation Due in 2019	20.0
Future Contingent Acquisition Obligation Due in 2020	12.7
Future Contingent Acquisition Obligation Due Thereafter	15.0
Future Contingent Acquisition Obligation Due, Total	315.7
Cash compensation expense included in contingent acquisitions
Business Acquisition, Contingent Consideration [Line Items]
Future Contingent Acquisition Obligation Due in 2016	0.2
Future Contingent Acquisition Obligation Due in 2017	0.2
Future Contingent Acquisition Obligation Due in 2018	0.1
Future Contingent Acquisition Obligation Due in 2019	0.1
Future Contingent Acquisition Obligation Due in 2020	0.1
Future Contingent Acquisition Obligation Due Thereafter	0.0
Future Contingent Acquisition Obligation Due, Total	0.7
Total contingent acquisition payments excluding compensation expense
Business Acquisition, Contingent Consideration [Line Items]
Future Contingent Acquisition Obligation Due in 2016	102.0
Future Contingent Acquisition Obligation Due in 2017	109.5
Future Contingent Acquisition Obligation Due in 2018	56.0
Future Contingent Acquisition Obligation Due in 2019	19.9
Future Contingent Acquisition Obligation Due in 2020	12.6
Future Contingent Acquisition Obligation Due Thereafter	15.0
Future Contingent Acquisition Obligation Due, Total	$ 315.0

[1] We have entered into certain acquisitions that contain both redeemable noncontrolling interests and call options with similar terms and conditions. The estimated amounts listed would be paid in the event of exercise at the earliest exercise date. We have certain redeemable noncontrolling interests that are exercisable at the discretion of the noncontrolling equity owners as of December 31, 2015. These estimated payments of $31.0 are included within the total payments expected to be made in 2016, and will continue to be carried forward into 2017 or beyond until exercised or expired. 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.