Segment Information Operations (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Segments:
Revenue	$ 1,676.0	$ 1,637.5
Operating Income (Loss)	7.8	(11.7)
Interest expense	20.9	20.2
Interest income	7.2	6.2
Other income, net	0.3	1.7
Loss before income taxes	(5.6)	(24.0)
Depreciation and amortization of fixed assets and intangible assets	38.7	40.5
Capital expenditures	20.2	26.6
IAN
Segments:
Revenue	1,349.9	1,315.7
Operating Income (Loss)	31.6	11.5
Depreciation and amortization of fixed assets and intangible assets	29.4	31.5
Capital expenditures	12.1	13.9
CMG
Segments:
Revenue	326.1	321.8
Operating Income (Loss)	19.7	17.5
Depreciation and amortization of fixed assets and intangible assets	4.6	4.2
Capital expenditures	1.1	2.5
Corporate and Other
Segments:
Operating Income (Loss)	(43.5)	(40.7)
Depreciation and amortization of fixed assets and intangible assets	4.7	4.8
Capital expenditures	$ 7.0	$ 10.2