Cover
Cover - USD ($) $ in Millions | 12 Months Ended | ||
Dec. 31, 2020 | Mar. 31, 2021 | Jun. 30, 2020 | |
Entity Information [Line Items] | |||
Document Type | 10-K/A | ||
Amendment Flag | false | ||
Document Annual Report | true | ||
Document Transition Report | false | ||
Document Period End Date | Dec. 31, 2020 | ||
Document Fiscal Period Focus | FY | ||
Document Fiscal Year Focus | 2020 | ||
Current Fiscal Year End Date | --12-31 | ||
Entity File Number | 001-13718 | ||
Entity Registrant Name | MDC PARTNERS INC. | ||
Entity Central Index Key | 0000876883 | ||
Entity Tax Identification Number | 98-0364441 | ||
Entity Incorporation, State or Country Code | Z4 | ||
Entity Address, Address Line One | One World Trade Center | ||
Entity Address, Address Line Two | Floor 65 | ||
Entity Address, City or Town | New York | ||
Entity Address, State or Province | NY | ||
Entity Address, Postal Zip Code | 10007 | ||
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 Well-known Seasoned Issuer | No | ||
Entity Voluntary Filers | No | ||
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 Public Float | $ 120 | ||
ICFR Auditor Attestation Flag | true | ||
Common Class A [Member] | |||
Entity Information [Line Items] | |||
Entity Common Stock, Shares Outstanding | 74,787,317 | ||
Common Class B [Member] | |||
Entity Information [Line Items] | |||
Entity Common Stock, Shares Outstanding | 3,743 |