UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Revenue:
Services	$ 326,968	$ 344,700
Operating expenses:
Cost of services sold	243,030	237,563
Office and general expenses	83,879	87,840
Depreciation and amortization	12,375	10,898
Other asset impairment	2,317	0
Costs and Expenses, Total	341,601	336,301
Operating profit (loss)	(14,633)	8,399
Other income (expense):
Other, net	(6,219)	2,567
Interest expense and finance charges	(16,231)	(16,768)
Interest income	148	227
Nonoperating Income (Expense), Total	(22,302)	(13,974)
Loss before income taxes and equity in earnings (losses) of non-consolidated affiliates	(36,935)	(5,575)
Income tax expense (benefit)	(8,330)	3,969
Loss before equity in earnings of non-consolidated affiliates	(28,605)	(9,544)
Equity in earnings (losses) of non-consolidated affiliates	86	(139)
Net loss	(28,519)	(9,683)
Net income attributable to noncontrolling interests	(897)	(883)
Net loss attributable to MDC Partners Inc.	(29,416)	(10,566)
Net loss attributable to MDC Partners Inc. common shareholders	$ (31,443)	$ (11,073)
Basic and diluted
Net loss attributable to MDC Partners Inc. common shareholders (in USD per share)	$ (0.56)	$ (0.21)
Weighted Average Number of Common Shares Outstanding:
Weighted Average Number of Shares Outstanding, Basic and Diluted (shares)	56,415,042	52,998,244
Stock-based compensation	$ 5,037	$ 4,950
Cost of services sold
Weighted Average Number of Common Shares Outstanding:
Stock-based compensation	3,347	3,511
Office and general expenses
Weighted Average Number of Common Shares Outstanding:
Stock-based compensation	1,690	1,439
Series 4 Convertible Preferred Stock [Domain] | Convertible Preferred Stock
Other income (expense):
Accretion on convertible preference shares	$ (2,027)	$ (507)