2004 Restatement Liabilities (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
2004 Restatement Liabilities [Abstract]
Vendor discounts and credit liabilities	$ 25.5	$ 26.9

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