Earnings Per Share Narrative (Details)	3 Months Ended	6 Months Ended
Jun. 30, 2016	Jun. 30, 2016
Earnings Per Share [Abstract]
Increase in shares in the effect of dilutive securities due to adoption of new guidance	1.8	1.5

Additional shares included in the calculation of diluted EPS as a result of adopting Accounting Standards Update 2016-09

No definition available.

Name:	ipg_IncrementalCommonSharesAttributabletoDilutiveEffectofShareBasedPaymentArrangementsduetoAdoptionofNewGuidance
Namespace Prefix:	ipg_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration