2004 Restatement Liabilities (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
2004 Restatement Liabilities [Abstract]
Vendor discounts and credit liabilities	$ 26.9	$ 55.5

Liabilities related to vendor discounts and credits where we have a contractual or legal obligation to rebate to clients or vendors.

No definition available.

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