UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Payments to Acquire Businesses, Net of Cash Acquired			$ 27,299	$ 0
Revenue:
Services	$ 379,743	$ 390,532	706,711	735,232
Operating expenses:
Cost of services sold	253,390	267,822	496,420	505,385
Office and general expenses	83,878	85,563	167,757	173,403
Depreciation and amortization	11,703	10,766	24,078	21,664
Other asset impairment	0	0	2,317	0
Costs and Expenses, Total	348,971	364,151	690,572	700,452
Operating profit (loss)	30,772	26,381	16,139	34,780
Other income (expense):
Other, net	(5,957)	6,596	(12,176)	9,163
Interest expense and finance charges	(17,018)	(15,688)	(33,249)	(32,456)
Interest income	159	178	307	405
Nonoperating Income (Expense), Total	(22,816)	(8,914)	(45,118)	(22,888)
Loss before income taxes and equity in earnings (losses) of non-consolidated affiliates	7,956	17,467	(28,979)	11,892
Income tax expense (benefit)	1,977	4,641	(6,353)	8,610
Loss before equity in earnings of non-consolidated affiliates	5,979	12,826	(22,626)	3,282
Equity in earnings (losses) of non-consolidated affiliates	(28)	641	58	502
Net loss	5,951	13,467	(22,568)	3,784
Net income attributable to noncontrolling interests	(2,545)	(2,214)	(3,442)	(3,097)
Net loss attributable to MDC Partners Inc.	3,406	11,253	(26,010)	687
Net loss attributable to MDC Partners Inc. common shareholders	1,133	7,960	(30,105)	(1,730)
Weighted Average Number of Common Shares Outstanding:
Stock-based compensation	$ 5,603	$ 5,540	$ 10,640	$ 10,490
Earnings Per Share, Basic	$ 0.02	$ 0.14	$ (0.53)	$ (0.03)
Earnings Per Share, Diluted	$ 0.02	$ 0.14	$ (0.53)	$ (0.03)
Weighted Average Number of Shares Outstanding, Basic	57,439,823	55,332,497	56,924,208	53,480,144
Cost of services sold
Weighted Average Number of Common Shares Outstanding:
Stock-based compensation	$ 4,047	$ 3,737	$ 7,394	$ 7,248
Office and general expenses
Weighted Average Number of Common Shares Outstanding:
Stock-based compensation	1,556	1,803	3,246	3,242
Series 4 Convertible Preferred Stock [Domain] | Convertible Preferred Stock
Other income (expense):
Accretion on convertible preference shares	$ (2,273)	$ (3,293)	$ (4,095)	$ (2,417)