CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Current assets:
Cash and cash equivalents	$ 18,861	$ 27,921
Cash held in trusts	5,182	5,341
Accounts receivable, less allowance for doubtful accounts of $1,933 and $1,523	438,765	388,340
Expenditures billable to clients	42,332	33,118
Other current assets	27,647	34,862
Total current assets	532,787	489,582
Fixed assets, at cost, less accumulated depreciation of $115,884 and $105,134	91,153	78,377
Investments in non-consolidated affiliates	5,655	4,745
Goodwill	839,361	844,759
Other intangible assets, net	74,685	85,071
Deferred tax assets	39,598	41,793
Other assets	34,592	33,051
Total assets	1,617,831	1,577,378
Current liabilities:
Accounts payable	232,704	251,456
Trust liability	5,182	5,341
Accruals and other liabilities	289,471	303,581
Advance billings	165,600	133,925
Current portion of long-term debt	300	228
Current portion of deferred acquisition consideration	59,849	108,290
Total current liabilities	753,106	802,821
Long-term debt, less current portion	930,889	936,208
Long-term portion of deferred acquisition consideration	88,419	121,274
Other liabilities	54,657	56,012
Deferred tax liabilities	119,602	110,359
Total liabilities	1,946,673	2,026,674
Redeemable noncontrolling interests (Note 2)	60,092	60,180
Shareholders’ deficit:
Charges in excess of capital	(307,454)	(311,581)
Accumulated deficit	(562,668)	(581,848)
Total shareholders’ deficit	(388,934)	(509,476)
Total liabilities, redeemable noncontrolling interests, and shareholders’ deficit	1,617,831	1,577,378
Common Class A
Shareholders’ deficit:
Common shares	351,075	317,784
Preferred Stock [Member] | Series 4 Convertible Preferred Stock [Domain]
Shareholders’ deficit:
Convertible preference shares (liquidation preference $97,417)	90,220
Total shareholders’ deficit	90,220	0
Share Capital To Be Issued [Member]
Shareholders’ deficit:
Shares to be issued, 100,000 shares in 2016	0	2,360
Share Capital To Be Issued [Member] | Common Class A
Shareholders’ deficit:
Shares to be issued, 100,000 shares in 2016	0	2,360
AOCI Including Portion Attributable to Noncontrolling Interest [Member]
Shareholders’ deficit:
Accumulated other comprehensive loss	(5,593)	(1,824)
Total shareholders’ deficit	(5,593)	(1,824)
Parent [Member]
Shareholders’ deficit:
MDC Partners Inc. shareholders’ deficit	(434,420)	(575,109)
Total shareholders’ deficit	(434,420)	(575,109)
Noncontrolling Interest [Member]
Shareholders’ deficit:
Noncontrolling interests	45,486	65,633
Total shareholders’ deficit	$ 45,486	$ 65,633