Guarantees (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Commitments and Contingencies Disclosure [Abstract]
Parent company guarantees on lease obligations	$ 829.2	$ 857.3
Parent company guarantees relating to credit facilities	491.0	$ 395.6
Assets pledged as security for parent company guarantees	$ 0.0

The current carrying amount of the liability for the freestanding or embedded guarantor's obligations under the credit facilities guarantees or each group of similar guarantees.

No definition available.

Name:	ipg_GuaranteeObligationsCurrentCarryingValueCreditfacilities
Namespace Prefix:	ipg_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant