Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Net Income	$ 266.7	$ 273.6	$ 839.2	$ 860.1
Unrealized loss on cash flow hedge, net of income taxes of ($21.2) for the three months and ($6.6) for the nine months ended September 30, 2015	(29.7)	0.0	(9.2)	0.0
Unrealized gain on available-for-sale securities, net of income taxes of $0.0 and $0.0 for the three months and $0.1 and $0.2 for the nine months ended September 30, 2015 and 2014, respectively	0.1	0.1	0.3	0.3
Foreign currency translation adjustment, net of income taxes of ($109.4) and ($181.7) for the three months and ($203.7) and ($128.4) for the nine months ended September 30, 2015 and 2014, respectively	(212.6)	(352.6)	(395.7)	(249.3)
Defined benefit pension and postemployment plans adjustment, net of income taxes of $1.4 and $0.9 for the three months and $4.4 and $2.7 for the nine months ended September 30, 2015 and 2014, respectively	2.2	1.3	6.6	4.1
Other Comprehensive Income (Loss)	(240.0)	(351.2)	(398.0)	(244.9)
Comprehensive Income (Loss)	26.7	(77.6)	441.2	615.2
Comprehensive Income (Loss) Attributed to Noncontrolling Interests	9.8	2.2	42.3	69.2
Comprehensive Income (Loss) - Omnicom Group Inc.	$ 16.9	$ (79.8)	$ 398.9	$ 546.0