CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($)	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015
Cash flows from operating activities:
Net loss	$ (52,478,000)	$ (3,792,000)
Loss from discontinued operations attributable to MDC Partners Inc., net of taxes	0	(6,281,000)
Loss from continuing operations	(52,478,000)	2,489,000
Adjustments to reconcile net loss from continuing operations to cash used in operating activities:
Stock-based compensation	15,443,000	13,025,000
Depreciation	16,853,000	13,666,000
Amortization of intangibles	17,215,000	25,727,000
Amortization of deferred finance charges and debt discount	8,736,000	1,702,000
Goodwill, Impairment Loss	29,631,000	0
Adjustment to deferred acquisition consideration	17,363,000	(3,866,000)
Deferred income tax	160,000	(1,020,000)
Gain (Loss) on Disposition of Assets	377,000	0
Earnings of non-consolidated affiliates	(9,000)	(627,000)
Other non-current assets and liabilities	1,853,000	3,930,000
Foreign exchange	(12,806,000)	24,739,000
Changes in working capital:
Accounts receivable	(47,767,000)	(63,134,000)
Expenditures billable to clients	5,551,000	(16,582,000)
Prepaid expenses and other current assets	(16,851,000)	(1,371,000)
Accounts payable, accruals and other liabilities	(94,887,000)	(84,000)
Advance billings	25,824,000	(7,741,000)
Net Cash Provided by (Used in) Operating Activities, Continuing Operations	(58,919,000)	(9,147,000)
Discontinued operations	0	(1,342,000)
Net cash used in operating activities	(58,919,000)	(10,489,000)
Cash flows used in investing activities:
Capital expenditures	(19,723,000)	(17,665,000)
Acquisitions, net of cash acquired	2,531,000	(21,050,000)
Proceeds from sale of assets	215,000	21,000
Other investments	(2,571,000)	(6,507,000)
Distributions from non-consolidated affiliates	4,885,000	2,478,000
Cash flows used in continuing investing activities	(14,663,000)	(42,723,000)
Discontinued operations	0	17,101,000
Net cash used in investing activities	(14,663,000)	(25,622,000)
Cash flows provided by financing activities:
Payments for (Proceeds from) Previous Acquisition	(129,616,000)	(132,997,000)
Repayment of long-term debt	(381,000)	(397,000)
Purchase of shares	(2,798,000)	(1,792,000)
Premium Paid On Redemption Of Notes	(26,873,000)	0
Payments of Financing Costs	(21,569,000)	0
Distributions to noncontrolling interests	(6,549,000)	(9,462,000)
Cash overdrafts	17,532,000	27,207,000
Payment of dividends	(32,580,000)	(31,692,000)
Cash flows provided by continuing financing activities	32,663,000	(63,633,000)
Discontinued operations	0	(40,000)
Net cash provided by financing activities	32,663,000	(63,673,000)
Effect of exchange rate changes on cash and cash equivalents	1,196,000	2,194,000
Decrease in cash and cash equivalents	(39,723,000)	(97,590,000)
Cash and cash equivalents at beginning of period	61,458,000	113,348,000
Cash and cash equivalents at end of period	21,735,000	15,758,000
Supplemental disclosures:
Cash income taxes paid	2,798,000	1,400,000
Cash interest paid	27,979,000	26,358,000
Change in assets held-in-trust	147,000	(752,000)
Non-cash transactions:
Capital leases	0	106,000
Dividends payable	1,077,000	1,615,000
Leasehold improvements financed by landlord	7,250,000	0
Six Point Seven Five Percentage Notes [Member]
Adjustments to reconcile net loss from continuing operations to cash used in operating activities:
Loss on redemption of notes	26,873,000	0
Cash flows provided by financing activities:
Proceeds from Issuance of Senior Long-term Debt	900,000,000	0
Repayments of Senior Debt	735,000,000	0
Wells Fargo Capital Finance, LLC | Revolving Credit Facility [Member]
Cash flows provided by financing activities:
Repayments of Lines of Credit	(1,255,608,000)	(447,973,000)
Proceeds from (Repayments of) Lines of Credit	1,326,105,000	533,249,000
Common Class A [Member] | Common Stock [Member]
Non-cash transactions:
Stock Issued During Period, Value, New Issues	10,458,000	0
Common Class A [Member] | Forsman & Bodenfors AB [Domain] | Common Stock [Member]
Non-cash transactions:
Stock Issued During Period, Value, Acquisitions	$ 34,219,000	$ 0