Temporary Equity - Redeemable Noncontrolling Interests	12 Months Ended
	Dec. 31, 2021
Temporary Equity - Redeemable Noncontrolling Interests [Abstract]
Temporary Equity - Redeemable Noncontrolling Interests	Temporary Equity - Redeemable Noncontrolling InterestsOwners of noncontrolling equity interests in some of our subsidiaries have the right in certain circumstances to require us to purchase all or a portion of their equity interest at fair value as defined in the applicable agreements. Assuming that the subsidiaries perform over the relevant periods at their current profit levels, at December 31, 2021 the aggregate estimated maximum amount we could be required to pay in future periods is $345.3 million, of which $107.5 million is currently exercisable by the holders. If these rights are exercised, there would be an increase in net income attributable to Omnicom as a result of our increased ownership interest and the reduction of net income attributable to noncontrolling interests. The ultimate amount paid could be significantly different because the redemption amount depends on the future results of operations of the subject businesses, the timing of the exercise of these rights and changes in foreign currency exchange rates.