CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Earnings Per Share, Basic	$ 0.14	$ 0.02	$ (0.03)	$ (0.45)
Earnings Per Share, Diluted	$ 0.14	$ 0.02	$ (0.03)	$ (0.45)
Revenue:
Services	$ 390,532	$ 337,047	$ 735,232	$ 646,089
Operating expenses:
Cost of services sold	267,822	228,835	505,385	440,281
Office and general expenses	85,563	72,709	173,403	150,537
Depreciation and amortization	10,766	11,436	21,664	22,656
Costs and Expenses, Total	364,151	312,980	700,452	613,474
Operating profit	26,381	24,067	34,780	32,615
Other income (expense):
Other, net	6,596	26	9,163	15,538
Interest expense and finance charges	(15,688)	(17,174)	(32,456)	(32,749)
Loss on redemption of notes	0	0	0	(33,298)
Interest income	178	203	405	381
Nonoperating Income (Expense), Total	(8,914)	(16,945)	(22,888)	(50,128)
Income (loss) before income taxes and equity in earnings of non-consolidated affiliates	17,467	7,122	11,892	(17,513)
Income tax expense	4,641	4,744	8,610	3,110
Income (loss) before equity in earnings of non-consolidated affiliates	12,826	2,378	3,282	(20,623)
Equity in earnings (loss) of non-consolidated affiliates	641	(290)	502	(61)
Net income (loss)	13,467	2,088	3,784	(20,684)
Net income attributable to noncontrolling interests	(2,214)	(1,254)	(3,097)	(2,113)
Net income (loss) attributable to MDC Partners Inc.	$ 11,253	$ 834	$ 687	$ (22,797)
Weighted average number of common shares outstanding:
Weighted Average Number of Shares Outstanding, Basic and Diluted	55,332,497	50,322,757	53,480,144	50,162,654
Share-based Compensation	$ 5,540	$ 5,530	$ 10,490	$ 10,215
Net Income (Loss) Available to Common Stockholders, Basic	9,343	834	(1,730)	(22,797)
Cost of Sales [Member]
Weighted average number of common shares outstanding:
Share-based Compensation	3,737	4,231	7,248	7,367
General and Administrative Expense [Member]
Weighted average number of common shares outstanding:
Share-based Compensation	1,803	1,299	3,242	2,848
Series 4 Convertible Preferred Stock [Domain] | Convertible Preferred Stock [Member]
Other income (expense):
Accretion on convertible preferred shares	$ (1,910)	$ 0	$ (2,417)	$ 0