Cover Page - shares	6 Months Ended
	Jun. 30, 2020	Aug. 06, 2020
Entity Information [Line Items]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Jun. 30, 2020
Document Transition Report	false
Entity File Number	001-13718
Entity Registrant Name	MDC Partners Inc
Entity Incorporation, State or Country Code	Z4
Entity Tax Identification Number	98-0364441
Entity Address, Address Line One	330 Hudson Street, 10th Floor
Entity Address, City or Town	New York,
Entity Address, State or Province	NY
Entity Address, Postal Zip Code	10013
City Area Code	646
Local Phone Number	429-1800
Title of 12(b) Security	Class A Subordinate Voting Shares, no par value
Trading Symbol	MDCA
Security Exchange Name	NASDAQ
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Central Index Key	0000876883
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	Q2
Amendment Flag	false
Common Class A
Entity Information [Line Items]
Entity Common Stock, Shares Outstanding		72,740,767
Common Class B
Entity Information [Line Items]
Entity Common Stock, Shares Outstanding		3,743