Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Net Income	$ 342.7	$ 358.4	$ 572.5	$ 586.5
Unrealized gain on cash flow hedge, net of income taxes of $16.4 for the three months and $14.6 for the six months ended June 30, 2015	23.0	0.0	20.5	0.0
Unrealized gain on available-for-sale securities, net of income taxes of $0.0 and $0.1 for the three months and $0.1 and $0.1 for the six months ended June 30, 2015 and 2014, respectively	0.0	0.1	0.2	0.2
Foreign currency translation adjustment, net of income taxes of $81.5 and $37.7 for the three months and ($94.3) and $53.3 for the six months ended June 30, 2015 and 2014, respectively	158.2	73.3	(183.1)	103.5
Defined benefit pension and postemployment plans adjustment, net of income taxes of $1.5 and $0.9 for the three months and $3.0 and $1.8 for the six months ended June 30, 2015 and 2014, respectively	2.2	1.4	4.4	2.8
Other Comprehensive Income (Loss)	183.4	74.8	(158.0)	106.5
Comprehensive Income	526.1	433.2	414.5	693.0
Comprehensive Income Attributed to Noncontrolling Interests	34.7	34.7	32.5	67.0
Comprehensive Income - Omnicom Group Inc.	$ 491.4	$ 398.5	$ 382.0	$ 626.0