Document And Entity Information - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Feb. 28, 2019	Jun. 29, 2018
Document Information [Line Items]
Trading Symbol	MDCA
Entity Registrant Name	MDC PARTNERS INC
Entity Central Index Key	0000876883
Current Fiscal Year End Date	--12-31
Entity Filer Category	Accelerated Filer
Document Type	10-K
Document Period End Date	Dec. 31, 2018
Document Fiscal Year Focus	2018
Document Fiscal Period Focus	FY
Amendment Flag	false
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Public Float			$ 0.0
Common Class A
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		58,432,677
Common Class B
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		3,755