Basis of Presentation	6 Months Ended
Jun. 30, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation	Basis of Presentation MDC Partners Inc. (the “Company” or “MDC”) has prepared the unaudited condensed consolidated interim financial statements included herein pursuant to the rules and regulations of the United States Securities and Exchange Commission (the “SEC”). Certain information and footnote disclosures normally included in annual financial statements prepared in accordance with generally accepted accounting principles of the United States of America (“U.S. GAAP”) have been condensed or omitted pursuant to these rules. The accompanying consolidated financial statements include the accounts of MDC Partners Inc. and its domestic and international controlled subsidiaries that are not considered variable interest entities, and variable interest entities for which the Company is the primary beneficiary. Intercompany balances and transactions have been eliminated in consolidation. The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions. These estimates and assumptions affect the reported amounts of assets and liabilities including goodwill, intangible assets, contingent deferred acquisition consideration, valuation allowances for receivables, deferred tax assets and the amounts of revenue and expenses reported during the period. These estimates are evaluated on an ongoing basis and are based on historical experience, current conditions and various other assumptions believed to be reasonable under the circumstances. Actual results could differ from these estimates. The accompanying financial statements reflect all adjustments, consisting of normally recurring accruals, which in the opinion of management are necessary for a fair presentation, in all material respects, of the information contained therein. Results of operations for interim periods are not necessarily indicative of annual results. References herein to “Partner Firms” generally refer to the Company’s subsidiary agencies. In August 2016, the Financial Accounting Standards Board (the “FASB”) issued Accounting Standards Update (“ASU”) 2016-15, Statement of Cash Flows, which clarifies how cash receipts and cash payments in certain transactions are presented and classified on the statement of cash flows. The new pronouncement states that any cash payments made soon after the acquisition date of a business to settle a contingent consideration liability are classified as cash outflows for investing activities. Cash payments which are not made soon after the acquisition date of a business to settle a contingent consideration liability are separated and classified as cash outflows for financing activities up to the amount of the contingent consideration liability recognized at the acquisition date and as cash outflows from operating activities for any excess. The Company adopted the provisions of ASU 2016-15 on January 1, 2018 on a retrospective basis. As a result, $24,459 of an acquisition-related contingent consideration payment of $65,121, which was in excess of the liability initially recognized at the acquisition date, has been classified as a cash outflow within net cash provided by operating activities in the accompanying unaudited condensed consolidated statement of cash flows for the six months ended June 30, 2017. These statements should be read in conjunction with the consolidated financial statements and related notes thereto included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2017 (“2017 Form 10-K”).

Basis of Presentation

MDC Partners Inc. (the “Company” or “MDC”) has prepared the unaudited condensed consolidated interim financial statements included herein pursuant to the rules and regulations of the United States Securities and Exchange Commission (the “SEC”). Certain information and footnote disclosures normally included in annual financial statements prepared in accordance with generally accepted accounting principles of the United States of America (“U.S. GAAP”) have been condensed or omitted pursuant to these rules.

The accompanying consolidated financial statements include the accounts of MDC Partners Inc. and its domestic and international controlled subsidiaries that are not considered variable interest entities, and variable interest entities for which the Company is the primary beneficiary. Intercompany balances and transactions have been eliminated in consolidation.

The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions. These estimates and assumptions affect the reported amounts of assets and liabilities including goodwill, intangible assets, contingent deferred acquisition consideration, valuation allowances for receivables, deferred tax assets and the amounts of revenue and expenses reported during the period. These estimates are evaluated on an ongoing basis and are based on historical experience, current conditions and various other assumptions believed to be reasonable under the circumstances. Actual results could differ from these estimates.

The accompanying financial statements reflect all adjustments, consisting of normally recurring accruals, which in the opinion of management are necessary for a fair presentation, in all material respects, of the information contained therein. Results of operations for interim periods are not necessarily indicative of annual results.

References herein to “Partner Firms” generally refer to the Company’s subsidiary agencies.

In August 2016, the Financial Accounting Standards Board (the “FASB”) issued Accounting Standards Update (“ASU”) 2016-15, Statement of Cash Flows, which clarifies how cash receipts and cash payments in certain transactions are presented and classified on the statement of cash flows. The new pronouncement states that any cash payments made soon after the acquisition date of a business to settle a contingent consideration liability are classified as cash outflows for investing activities. Cash payments which are not made soon after the acquisition date of a business to settle a contingent consideration liability are separated and classified as cash outflows for financing activities up to the amount of the contingent consideration liability recognized at the acquisition date and as cash outflows from operating activities for any excess. The Company adopted the provisions of ASU 2016-15 on January 1, 2018 on a retrospective basis. As a result, $24,459 of an acquisition-related contingent consideration payment of $65,121, which was in excess of the liability initially recognized at the acquisition date, has been classified as a cash outflow within net cash provided by operating activities in the accompanying unaudited condensed consolidated statement of cash flows for the six months ended June 30, 2017.

These statements should be read in conjunction with the consolidated financial statements and related notes thereto included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2017 (“2017 Form 10-K”).