Document And Entity Information - shares	9 Months Ended
	Sep. 30, 2015	Oct. 26, 2015
Document Information [Line Items]
Entity Registrant Name	MDC PARTNERS INC
Entity Central Index Key	0000876883
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Trading Symbol	MDCA
Document Type	10-Q
Document Period End Date	Sep. 30, 2015
Document Fiscal Year Focus	2015
Document Fiscal Period Focus	Q3
Amendment Flag	false
Common Class A
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		50,794,578
Common Class B
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		3,755