Segment Information (Details 1) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2018 USD ($) reportable_segment	Mar. 31, 2017 USD ($)	Dec. 31, 2017 USD ($)
Segment Reporting Information [Line Items]
Number of reportable segments | reportable_segment	4
Revenue	$ 326,968	$ 344,700
Segment operating income (loss)	(14,633)	8,399
Other Income (Expense):
Other (expense) income, net	(6,219)	2,567
Interest expense and finance charges, net	(16,083)	(16,541)
Loss before income taxes and equity in earnings 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 the noncontrolling interest	(897)	(883)	$ (15,375)
Net loss attributable to MDC Partners Inc.	(29,416)	(10,566)
Depreciation and amortization	12,375	10,898
Stock-based compensation	5,037	4,950
Capital expenditures	3,799	9,413
Global Integrated Agencies
Segment Reporting Information [Line Items]
Revenue	150,355	179,225
Segment operating income (loss)	(15,761)	(626)
Other Income (Expense):
Net loss attributable to MDC Partners Inc.	(29,416)	(10,566)
Depreciation and amortization	8,016	5,961
Stock-based compensation	2,547	2,989
Capital expenditures	2,837	6,907
Domestic Creative Agencies
Segment Reporting Information [Line Items]
Revenue	21,296	20,910
Segment operating income (loss)	3,454	3,523
Other Income (Expense):
Depreciation and amortization	353	360
Stock-based compensation	149	155
Capital expenditures	191	286
Specialized Communications
Segment Reporting Information [Line Items]
Revenue	43,150	40,684
Segment operating income (loss)	4,027	4,335
Other Income (Expense):
Depreciation and amortization	1,002	1,216
Stock-based compensation	336	518
Capital expenditures	240	291
Media Services
Segment Reporting Information [Line Items]
Revenue	31,257	35,244
Segment operating income (loss)	487	2,642
Other Income (Expense):
Depreciation and amortization	644	1,005
Stock-based compensation	74	160
Capital expenditures	193	1,014
All Other
Segment Reporting Information [Line Items]
Revenue	80,910	68,637
Segment operating income (loss)	7,232	7,094
Other Income (Expense):
Depreciation and amortization	2,136	2,047
Stock-based compensation	683	524
Capital expenditures	330	914
Corporate, Non-Segment
Segment Reporting Information [Line Items]
Segment operating income (loss)	(14,072)	(8,569)
Other Income (Expense):
Depreciation and amortization	224	309
Stock-based compensation	1,248	604
Capital expenditures	$ 8	$ 1