Condensed Consolidated Statements of Income (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Revenue	$ 3,561.0	$ 3,487.4	$ 6,868.2	$ 6,638.8
Operating Expenses	3,054.6	2,999.3	5,999.3	5,828.5
Operating Income	506.4	488.1	868.9	810.3
Interest Expense	44.0	36.9	82.5	78.8
Interest Income	9.1	9.3	18.5	18.9
Income Before Income Taxes and Income From Equity Method Investments	471.5	460.5	804.9	750.4
Income Tax Expense	161.9	158.1	271.2	231.9
Income From Equity Method Investments	4.6	4.8	6.5	5.9
Net Income	314.2	307.2	540.2	524.4
Less: Net Income Attributed To Noncontrolling Interests	31.5	32.1	52.9	47.4
Net Income - Omnicom Group Inc.	$ 282.7	$ 275.1	$ 487.3	$ 477.0
Net Income Per Share - Omnicom Group Inc.:
Basic	$ 1.03	$ 0.98	$ 1.76	$ 1.68
Diluted	$ 1.02	$ 0.96	$ 1.74	$ 1.65
Dividends Declared Per Common Share	$ 0.30	$ 0.25	$ 0.60	$ 0.50