Condensed Consolidated Statements of Income (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Revenue	$ 3,398.9	$ 3,307.3
Operating Expenses	3,027.2	2,944.8
Operating Income	371.7	362.5
Interest Expense	49.0	38.5
Interest Income	8.1	9.3
Income Before Income Taxes and Income From Equity Method Investments	330.8	333.3
Income Tax Expense	109.2	109.3
Income From Equity Method Investments	3.2	2.0
Net Income	224.8	226.0
Less: Net Income Attributed To Noncontrolling Interests	19.7	21.4
Net Income - Omnicom Group Inc.	$ 205.1	$ 204.6
Net Income Per Share - Omnicom Group Inc.:
Basic	$ 0.76	$ 0.73
Diluted	$ 0.76	$ 0.72
Dividends Declared Per Common Share	$ 0.40	$ 0.30