Loss Per Common Share (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Numerator
Numerator for basic income (loss) per common share - loss from continuing operations	$ 18,371	$ 12,651	$ 10,993	$ (27,343)
Net income attributable to the noncontrolling interests	(1,749)	(1,514)	(3,111)	(2,496)
Net income (loss) attributable to MDC Partners Inc. common shareholders	16,622	11,137	7,882	(29,839)
Effect of dilutive securities	0	0	0	0
Numerator for diluted income (loss) per common share - loss attributable to MDC Partners Inc. common shareholders from continuing operations	$ 16,622	$ 11,137	$ 7,882	$ (29,839)
Denominator
Denominator for basic income (loss) per common share - weighted average common shares	49,546,062	47,098,392	49,442,770	46,975,299
Effect of dilutive securities	649,259	4,076,045	663,775	0
Denominator for diluted income (loss) per common share - adjusted weighted shares and assumed conversions	50,195,321	51,174,437	50,106,545	46,975,299
Income (loss) from continuing operations attributable to MDC Partners Inc. common shareholders (usd per share)	$ 0.34	$ 0.24	$ 0.16	$ (0.64)
Income (loss) from continuing operations attributable to MDC Partners Inc. common shareholders (usd per share)	$ 0.33	$ 0.22	$ 0.16	$ (0.64)