Condensed Consolidated Statements of Income (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Revenue	$ 3,490.5	$ 3,406.6	$ 10,526.4	$ 10,274.8
Operating Expenses	3,111.1	3,019.3	9,252.2	9,018.6
Operating Income	379.4	387.3	1,274.2	1,256.2
Interest Expense	50.5	47.8	148.8	130.3
Interest Income	7.7	7.5	24.2	26.0
Income Before Income Taxes and Income From Equity Method Investments	336.6	347.0	1,149.6	1,151.9
Income Tax Expense	116.2	118.7	388.9	389.9
Income From Equity Method Investments	4.3	5.3	10.5	11.9
Net Income	224.7	233.6	771.2	773.9
Less: Net Income Attributed To Noncontrolling Interests	28.7	29.7	80.5	82.7
Net Income - Omnicom Group Inc.	$ 196.0	$ 203.9	$ 690.7	$ 691.2
Net Income Per Share - Omnicom Group Inc.:
Basic	$ 0.74	$ 0.75	$ 2.60	$ 2.51
Diluted	$ 0.74	$ 0.74	$ 2.58	$ 2.49
Dividends Declared Per Common Share	$ 0.40	$ 0.30	$ 1.20	$ 0.90