CONDENSED CONSOLIDATED STATEMENTS OF INCOME (USD $) In Millions, except Per Share data	3 Months Ended		9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010
REVENUE	$ 3,380.9	$ 2,994.6	$ 10,019.6	$ 8,955.7
OPERATING EXPENSES	3,007.5	2,680.5	8,835.9	7,935.1
OPERATING INCOME	373.4	314.1	1,183.7	1,020.6
INTEREST EXPENSE	39.8	36.1	118.6	95.9
INTEREST INCOME	7.9	6.3	26.8	18.2
INCOME BEFORE INCOME TAXES AND INCOME FROM EQUITY METHOD INVESTMENTS	341.5	284.3	1,091.9	942.9
INCOME TAX EXPENSE	117.1	96.9	349.0	320.8
INCOME FROM EQUITY METHOD INVESTMENTS	4.5	8.2	10.3	23.1
NET INCOME	228.9	195.6	753.2	645.2
LESS: NET INCOME ATTRIBUTED TO NONCONTROLLING INTERESTS	25.2	21.0	72.5	64.0
NET INCOME - OMNICOM GROUP INC.	$ 203.7	$ 174.6	$ 680.7	$ 581.2
NET INCOME PER COMMON SHARE - OMNICOM GROUP INC.:
Basic	$ 0.73	$ 0.58	$ 2.41	$ 1.90
Diluted	$ 0.72	$ 0.57	$ 2.37	$ 1.88
DIVIDENDS DECLARED PER COMMON SHARE	$ 0.25	$ 0.20	$ 0.75	$ 0.60