Segment Information Operations (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Segments:
Revenue	$ 1,637.5	$ 1,543.0
Operating Income (Loss)	(11.7)	(42.4)
Interest expense	20.2	36.8
Interest income	6.2	6.4
Other income, net	1.7	1.8
Loss before income taxes	(24.0)	(71.0)
Depreciation and amortization of fixed assets and intangible assets	40.5	38.2
Capital expenditures	26.6	17.8
IAN
Segments:
Revenue	1,315.7	1,241.1
Operating Income (Loss)	11.5	(22.6)
Depreciation and amortization of fixed assets and intangible assets	31.5	30.9
Capital expenditures	13.9	10.0
CMG
Segments:
Revenue	321.8	301.9
Operating Income (Loss)	17.5	14.0
Depreciation and amortization of fixed assets and intangible assets	4.2	3.8
Capital expenditures	2.5	1.0
Corporate and Other
Segments:
Operating Income (Loss)	(40.7)	(33.8)
Depreciation and amortization of fixed assets and intangible assets	4.8	3.5
Capital expenditures	$ 10.2	$ 6.8