Consolidated Statements of Comprehensive Income (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Net Income	$ 1,117.5	$ 1,060.4	$ 923.7
Unrealized holding gain (loss) on available-for-sale securities, net of income taxes of $0.2, ($0.4) and $0.1 for 2012, 2011 and 2010, respectively	0.3	(0.6)	0.1
Foreign currency translation adjustments, net of income taxes of $41.3, ($41.2) and ($37.6) for 2012, 2011 and 2010, respectively	80.3	(79.7)	(73.0)
Defined benefit plans adjustment, net of income taxes of ($14.5), ($9.1) and ($9.0) for 2012, 2011 and 2010, respectively	(21.7)	(13.6)	(13.6)
Other Comprehensive Income	58.9	(93.9)	(86.5)
Comprehensive Income	1,176.4	966.5	837.2
Less: Comprehensive Income attributed to noncontrolling interests	115.9	99.2	107.9
Comprehensive Income - Omnicom Group Inc.	$ 1,060.5	$ 867.3	$ 729.3