Condensed Consolidated Statements of Comprehensive Income (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Net Income	$ 358.4	$ 321.6	$ 586.5	$ 546.5
Unrealized gain (loss) on available-for-sale securities, net of income taxes of $0.1 and $0.1 for the three months and $0.1 and $0.2 for the six months ended June 30, 2014 and 2013, respectively	0.1	0.1	0.2	0.3
Foreign currency translation adjustment, net of income taxes of $37.7 and ($63.5) for the three months and $53.3 and ($158.0) for the six months ended June 30, 2014 and 2013, respectively	73.3	(123.3)	103.5	(306.6)
Defined benefit pension and postemployment plans adjustment, net of income taxes of $0.9 and $1.1 for the three months and $1.8 and $2.4 for the six months ended June 30, 2014 and 2013, respectively	1.4	1.7	2.8	3.4
Other Comprehensive Income (Loss)	74.8	(121.5)	106.5	(302.9)
Comprehensive Income	433.2	200.1	693.0	243.6
Comprehensive Income Attributed to Noncontrolling Interests	(34.7)	(7.6)	(67.0)	(16.8)
Comprehensive Income - Omnicom Group Inc.	$ 398.5	$ 192.5	$ 626.0	$ 226.8