Segment Information Operations (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Segments:
Revenue	$ 1,506.8	$ 1,474.8
Segment operating income (loss)	(39.4)	(44.5)
Restructuring and other reorganization-related charges, net	0	(0.8)
Interest expense	(32.6)	(31.9)
Interest income	8.0	8.3
Other expense, net	(1.3)	(6.1)
Loss before income taxes	(65.3)	(75.0)
Depreciation and amortization of fixed assets and intangible assets	34.6	35.6
Capital expenditures	22.4	16.9
IAN
Segments:
Segment revenue	1,243.9	1,235.9
Segment operating income (loss)	(15.3)	(21.4)
Depreciation and amortization of fixed assets and intangible assets	28.4	29.3
Capital expenditures	12.8	14.0
CMG
Segments:
Segment revenue	262.9	238.9
Segment operating income (loss)	7.5	10.7
Depreciation and amortization of fixed assets and intangible assets	3.4	3.1
Capital expenditures	2.0	1.3
Corporate and other
Segments:
Segment operating income (loss)	(31.6)	(33.8)
Depreciation and amortization of fixed assets and intangible assets	2.8	3.2
Capital expenditures	$ 7.6	$ 1.6