Segment Information Balance Sheet (Details) - USD ($) $ in Millions	Jun. 30, 2015	Dec. 31, 2014
Financial Data:
Assets	$ 11,499.3	$ 12,747.2
IAN
Financial Data:
Assets	10,156.4	11,111.2
CMG
Financial Data:
Assets	1,275.2	1,316.5
Corporate and Other
Financial Data:
Assets	$ 67.7	$ 319.5