Segment Information (Details 1)	3 Months Ended								12 Months Ended
	Dec. 31, 2019 USD ($)	Sep. 30, 2019 USD ($)	Jun. 30, 2019 USD ($)	Mar. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Sep. 30, 2018 USD ($)	Jun. 30, 2018 USD ($)	Mar. 31, 2018 USD ($)	Dec. 31, 2019 USD ($) reportable_segment operating_segment	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)
Segment Reporting Information [Line Items]
Number of reportable segments | reportable_segment									4
Revenue	$ 381,975,000	$ 342,907,000	$ 362,130,000	$ 328,791,000	$ 393,662,000	$ 375,830,000	$ 379,743,000	$ 326,968,000	$ 1,415,803,000	$ 1,476,203,000	$ 1,513,779,000
Segment operating income (loss)									80,240,000	9,696,000	131,959,000
Interest expense and finance charges									(64,942,000)	(67,075,000)
Interest Expense, Other											64,364,000
Foreign exchange gain (loss)	4,349,000				(13,324,000)				8,750,000	(23,258,000)	18,137,000
Other, net									(2,401,000)	230,000	1,346,000
Income (loss) before income taxes and equity in earnings of non-consolidated affiliates									21,647,000	(80,407,000)	87,078,000
Income tax expense (benefit)									10,533,000	31,603,000	(168,064,000)
Income (loss) before equity in earnings of non-consolidated affiliates									11,114,000	(112,010,000)	255,142,000
Equity in earnings of non-consolidated affiliates									352,000	62,000	2,081,000
Net income (loss)									11,466,000	(111,948,000)	257,223,000
Income (Loss) from Continuing Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest	(1,696,000)	5,513,000	7,333,000	316,000	(75,713,000)	(13,667,000)	5,951,000	(28,519,000)			257,223,000
Net income attributable to the noncontrolling interest									(16,156,000)	(11,785,000)	(15,375,000)
Net income (loss) attributable to MDC Partners Inc.	(7,115,000)	$ (1,752,000)	$ 4,290,000	$ (113,000)	(81,598,000)	$ (16,125,000)	$ 3,406,000	$ (29,416,000)	(4,690,000)	(123,733,000)	241,848,000
Depreciation and amortization									38,329,000	46,196,000	43,474,000
Stock-based compensation	$ 18,408,000				$ 1,534,000				31,040,000	18,416,000	24,350,000
Capital expenditures									$ 18,596,000	20,264,000	32,958,000
Global Integrated Agencies
Segment Reporting Information [Line Items]
Number of operating segments | operating_segment									4
Revenue									$ 598,184,000	610,290,000	688,011,000
Segment operating income (loss)									58,933,000	63,972,000	60,891,000
Depreciation and amortization									16,572,000	21,179,000	21,206,000
Stock-based compensation									26,207,000	8,095,000	14,666,000
Capital expenditures									$ 8,223,000	8,731,000	18,897,000
Domestic Creative Agencies
Segment Reporting Information [Line Items]
Number of operating segments | operating_segment									7
Revenue									$ 230,718,000	246,642,000	277,587,000
Segment operating income (loss)									28,254,000	51,000	38,221,000
Depreciation and amortization									4,843,000	5,052,000	5,143,000
Stock-based compensation									1,532,000	2,623,000	2,301,000
Capital expenditures									$ 3,044,000	2,692,000	4,695,000
Specialized Communications
Segment Reporting Information [Line Items]
Number of operating segments | operating_segment									4
Revenue									$ 180,591,000	163,367,000
Segment operating income (loss)									23,822,000	17,316,000
Depreciation and amortization									2,577,000	4,113,000	4,567,000
Stock-based compensation									209,000	372,000	2,160,000
Capital expenditures									1,166,000	3,553,000	1,181,000
Specialist Communications [Member]
Segment Reporting Information [Line Items]
Revenue											153,506,000
Segment operating income (loss)											19,978,000
Media Services
Segment Reporting Information [Line Items]
Revenue									97,825,000	121,859,000	150,198,000
Segment operating income (loss)									(5,398,000)	(51,169,000)	13,900,000
Depreciation and amortization									3,261,000	2,693,000	3,709,000
Stock-based compensation									20,000	276,000	614,000
Capital expenditures									194,000	806,000	3,035,000
All Other
Segment Reporting Information [Line Items]
Revenue									308,485,000	334,045,000	244,477,000
Segment operating income (loss)									20,397,000	34,683,000	39,825,000
Depreciation and amortization									10,208,000	12,397,000	7,751,000
Stock-based compensation									1,192,000	2,391,000	2,475,000
Capital expenditures									5,933,000	4,415,000	5,127,000
Corporate, Non-Segment
Segment Reporting Information [Line Items]
Segment operating income (loss)									(45,768,000)	(55,157,000)	(40,856,000)
Depreciation and amortization									868,000	762,000	1,098,000
Stock-based compensation									1,880,000	4,659,000	2,134,000
Capital expenditures									$ 36,000	$ 67,000	$ 23,000