Segment Information - Schedule of Segment Reporting Information, by Segment (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Segment Reporting Information [Line Items]
Revenue	$ 359,013	$ 328,415	$ 336,606	$ 302,222	$ 339,911	$ 309,391	$ 299,356	$ 274,854	$ 1,326,256	$ 1,223,512	$ 1,062,478
Cost of services sold	231,330	212,925	225,042	210,419	222,626	205,549	188,875	181,468	879,716	798,518	704,969
Office and general expenses									322,207	290,073	355,964
Depreciation and amortization									52,223	47,172	36,139
Operating income (loss)									72,110	87,749	(34,594)
Other Income (Expense):
Other income, net									7,238	689	2,531
Foreign exchange loss									(39,328)	(18,482)	(5,516)
Interest expense and finance charges, net									(57,436)	(54,847)	(100,271)
Income (loss) from continuing operations before income taxes and equity in earnings of non-consolidated affiliates									(17,416)	15,109	(137,850)
Income tax expense									5,664	12,422	(4,367)
Income (loss) from continuing operations before equity in earnings of non-consolidated affiliates									(23,080)	2,687	(133,483)
Equity in earnings of non-consolidated affiliates									1,058	1,406	281
Income (loss) from continuing operations	(24,511)	(5,166)	31,072	(23,417)	(6,381)	(1,868)	19,555	(7,213)	(22,022)	4,093	(133,202)
Loss from discontinued operations attributable to MDC Partners Inc., net of taxes									(6,281)	(21,260)	(9,200)
Net loss									(28,303)	(17,167)	(142,402)
Net income attributable to the noncontrolling interests									(9,054)	(6,890)	(6,461)
Net loss attributable to MDC Partners Inc.	(26,222)	$ (8,604)	$ 29,560	$ (32,091)	(26,759)	$ (4,922)	$ 16,470	$ (8,846)	(37,357)	(24,057)	(148,863)
Stock-based compensation									17,796	17,696	100,405
Capital expenditures from continuing operations									23,575	26,416	16,809
Intangible Assets, Net (Including Goodwill)	942,683				937,494				942,683	937,494	800,595
Total assets	1,590,250				1,648,890				1,590,250	1,648,890	1,425,227
Strategic Marketing Services
Segment Reporting Information [Line Items]
Revenue									1,326,256	1,223,512	1,062,478
Cost of services sold									879,716	798,518	704,969
Office and general expenses									258,809	223,781	212,933
Depreciation and amortization									50,449	45,387	34,745
Operating income (loss)									137,282	155,826	109,831
Other Income (Expense):
Net income attributable to the noncontrolling interests									(9,024)	(6,890)	(6,459)
Stock-based compensation									15,056	12,033	8,950
Capital expenditures from continuing operations									23,204	25,079	14,677
Intangible Assets, Net (Including Goodwill)	942,683				937,494				942,683	937,494	800,595
Total assets	1,375,372				1,368,137				1,375,372	1,368,137	1,220,753
Corporate Segment
Segment Reporting Information [Line Items]
Revenue									0	0	0
Cost of services sold									0	0	0
Office and general expenses									63,398	66,292	143,031
Depreciation and amortization									1,774	1,785	1,394
Operating income (loss)									(65,172)	(68,077)	(144,425)
Other Income (Expense):
Net income attributable to the noncontrolling interests									(30)	0	(2)
Stock-based compensation									2,740	5,663	91,455
Capital expenditures from continuing operations									371	1,337	2,132
Intangible Assets, Net (Including Goodwill)	0				0				0	0	0
Total assets	$ 214,878				$ 280,753				$ 214,878	$ 280,753	$ 204,474