CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Earnings Per Share, Basic	$ 0.25	$ (0.62)	$ 0.24	$ (1.08)
Earnings Per Share, Diluted	$ 0.24	$ (0.62)	$ 0.24	$ (1.08)
Revenue:
Services	$ 375,800,000	$ 349,254,000	$ 1,111,032,000	$ 995,343,000
Operating expenses:
Cost of services sold	249,418,000	235,659,000	754,803,000	675,940,000
Office and general expenses	77,910,000	83,303,000	251,313,000	233,840,000
Depreciation and amortization	11,252,000	11,412,000	32,916,000	34,068,000
Goodwill, Impairment Loss	0	29,631,000	0	29,631,000
Costs and Expenses, Total	338,580,000	360,005,000	1,039,032,000	973,479,000
Operating profit	37,220,000	(10,751,000)	72,000,000	21,864,000
Other income (expense):
Other, net	8,649,000	(6,008,000)	17,812,000	9,530,000
Interest and Debt Expense	16,403,000	16,540,000	48,859,000	49,289,000
Loss on redemption of notes	0	0	0	(33,298,000)
Interest income	145,000	218,000	550,000	599,000
Nonoperating Income (Expense), Total	(7,609,000)	(22,330,000)	(30,497,000)	(72,458,000)
Income (loss) before income taxes and equity in earnings of non-consolidated affiliates	29,611,000	(33,081,000)	41,503,000	(50,594,000)
Income tax expense	9,049,000	(1,930,000)	17,659,000	1,180,000
Income (loss) before equity in earnings of non-consolidated affiliates	20,562,000	(31,151,000)	23,844,000	(51,774,000)
Equity in earnings (loss) of non-consolidated affiliates	1,422,000	70,000	1,924,000	9,000
Net income (loss)	21,984,000	(31,081,000)	25,768,000	(51,765,000)
Net income attributable to noncontrolling interests	(3,491,000)	(1,059,000)	(6,588,000)	(3,172,000)
Net income (loss) attributable to MDC Partners Inc.	$ 18,493,000	$ (32,140,000)	$ 19,180,000	$ (54,937,000)
Weighted average number of common shares outstanding:
Weighted Average Number of Shares Outstanding, Basic and Diluted	57,566,707	52,244,819	53,915,536	50,861,890
Share-based Compensation	$ 6,380,000	$ 5,228,000	$ 16,870,000	$ 15,443,000
Net Income (Loss) Available to Common Stockholders, Basic	16,545,000	(32,140,000)	14,815,000	(54,937,000)
Cost of Sales [Member]
Weighted average number of common shares outstanding:
Share-based Compensation	5,310,000	3,026,000	12,558,000	10,393,000
General and Administrative Expense [Member]
Weighted average number of common shares outstanding:
Share-based Compensation	1,070,000	2,202,000	4,312,000	5,050,000
Series 4 Convertible Preferred Stock [Domain] | Convertible Preferred Stock [Member]
Other income (expense):
Accretion on convertible preferred shares	$ (1,948,000)	$ 0	$ (4,365,000)	$ 0