Related Party Transactions	3 Months Ended
Mar. 31, 2018
Related Party Transactions [Abstract]
Related Party Transactions	(12) Related Party Transactions Employee Loans The Company periodically extends short term loans or advances to employees, typically upon commencement of employment. Total receivables as a result of these employee advances of $0.2 million existed at March 31, 2018 and December 31, 2017, respectively, and are included in the Prepaid expenses and other current assets and Other assets line items of the condensed consolidated balance sheets, respectively, depending on the contractual repayment date. Service Agreements Coherus BioSciences, Inc. (“Coherus”) The chief executive officer of the Company was a member of Coherus’s board of directors until his resignation in the first quarter of 2018. Coherus is no longer considered a related party as of the first quarter of 2018. During the three months ended March 31, 2017, the Company recognized service revenue from Coherus of $3.3 million in the Company’s condensed consolidated statements of operations. In addition, the company recognized Reimbursed out-of-pocket revenue with Coherus in the condensed consolidated statements of operations of $0.6 million during the three months ended March 31, 2017. As of December 31, 2017, the Company had Accounts receivable and unbilled, net from Coherus of $0.3 million recorded in the condensed consolidated balance sheets. As of December 31, 2017, the Company had, from Coherus, $1.5 million of Advanced billings and $1.0 million of Pre-funded study costs, in the condensed consolidated balance sheets. Xenon Pharmaceuticals, Inc. (“Xenon”) Certain executives and employees of the Company, including the chief executive officer, have held equity investments in Xenon, a clinical-stage biopharmaceutical company. During the second quarter of 2017, the chief executive officer sold his entire equity position held in Xenon. Xenon is no longer considered to be a related party subsequent to this sale. The Company recognized service revenue from Xenon of $0.5 million during the three months ended March 31, 2017 in the Company’s condensed consolidated statements of operations. Cymabay Therapeutics, Inc. (“Cymabay”) Cymabay is a clinical-stage biopharmaceutical company developing therapies to treat metabolic diseases with high unmet medical need, including serious rare and orphan disorders. During the first quarter of 2016, it was announced that a Medpace employee would join Cymabay’s board of directors. The Company and Cymabay entered into a MSA dated October 21, 2016. Subsequently, the Company and Cymabay have entered into several task orders for the Company to perform clinical trial related services. During the three months ended March 31, 2018, the Company recognized total revenue from Cymabay of $0.7 million and for the three months ended March 31, 2017, the Company recognized service revenue from Cymabay of $0.1 million in the Company’s condensed consolidated statements of operations. As of March 31, 2018 and December 31, 2017, respectively, the Company had Accounts receivable and unbilled, net from Cymabay of $0.6 million and $0.1 million recorded in the condensed consolidated balance sheets. As of March 31, 2018, the Company had, from Cymabay, $0.1 million in Advanced billings. LIB Therapeutics LLC (“LIB”) Certain executives and employees of the Company, including the chief executive officer, are members of LIB’s board of managers. The Company entered into a MSA dated November 24, 2015 with LIB, a company that engages in research, development, marketing and commercialization of pharmaceutical drugs. Subsequently, the Company and LIB have entered into several task orders for the Company to perform clinical trial related services. During the three months ended March 31, 2018, the Company recognized total revenue from LIB of $0.8 million and for the three months ended March 31, 2017, the Company recognized service revenue from LIB of $0.1 million, respectively, in the Company’s condensed consolidated statements of operations. As of March 31, 2018 and December 31, 2017, respectively, the Company had Advanced billings from LIB of $0.2 million and $0.2 million recorded in the condensed consolidated balance sheets. In addition, as of March 31, 2018 and December 31, 2017, respectively, the Company had Accounts receivable and unbilled, net from LIB of $0.7 million and $0.5 million recorded in the condensed consolidated balance sheets. Purchase of Real Estate Properties In December 2016, the Company entered into a purchase agreement for four parcels of real estate property that are closely situated to the Medpace campus in Cincinnati, Ohio, from AT Redevelopment Company, LLC, which is wholly-owned by the Company’s chief executive officer. The purchase price of the real estate property was $0.4 million as determined by an independent third party broker's opinion of value. The transaction closed on January 11, 2017. Leased Real Estate Headquarters Lease The Company entered into an operating lease for its corporate headquarters with an entity that is wholly owned by the chief executive officer of the Company. The Company has evaluated its relationship with the related party and concluded that the related party is not a variable interest entity because the Company has no direct ownership interest or relationship other than the lease. The lease for headquarters is for an initial term of twelve years through November 2022 with a renewal option for one 10-year term at prevailing market rates. The Company pays rent, taxes, insurance, and maintenance expenses that arise from the use of the property. Annual base rent for the corporate headquarters allows for adjustments to the rental rate annually for increases in the consumer price index. Lease expense recognized for each of the three months ended March 31, 2018 and 2017 was $0.5 million, respectively. The lease expense was allocated between Total direct costs and Selling, general and administrative in the condensed consolidated statements of operations. Deemed Assets and Deemed Landlord Liabilities The Company entered into two multi-year lease agreements governing the occupancy of space of two buildings in Cincinnati, Ohio with an entity that is wholly owned by the Company’s chief executive officer and certain members of his immediate family. In accordance with the accounting guidance related to leases, the Company was deemed in substance to be the owner of the property during the construction phase and at completion. Accordingly, the Company reflected the buildings and related liabilities as deemed assets from landlord building construction in Property and equipment, net, Other current liabilities, and Deemed landlord liability, less current portion, respectively, on the condensed consolidated balance sheets. The Company assumed occupancy in 2012 and the leases expire in 2027 with the Company having one 10-year option to extend the lease term. The deemed assets are being fully depreciated, on a straight line basis, over the 15-year term of the lease. Deemed landlord liabilities are recorded at their net present value when the Company enters into qualifying leases and are reduced as the Company makes periodic lease payments on the properties. Accretion expense is being recorded over the term of the lease as a component of Interest expense, net in the Company’s condensed consolidated statements of operations. The Company paid $1.0 million and $0.9 million during the three months ended March 31, 2018 and 2017, respectively. The current and long-term portions of the Deemed landlord liability at March 31, 2018 were $2.0 million and $26.1 million, respectively. The current and long-term portions of the Deemed landlord liability at December 31, 2017 were $1.9 million and $26.6 million, respectively. The Company has recognized deemed assets, net of $15.9 million and $16.3 million at March 31, 2018 and December 31, 2017, respectively, in the condensed consolidated balance sheets. Travel Services The Company incurs expenses for travel services for company executives provided by a private aviation charter company that is owned by the chief executive officer and the executive vice president of operations of the Company (“private aviation charter”). The Company may contract directly with the private aviation charter for the use of its aircraft or indirectly through a third party aircraft management and jet charter company (the “Aircraft Management Company”). The travel services provided are primarily for business purposes, with certain personal travel paid for as part of the executives’ compensation arrangements. The Aircraft Management Company also makes the private aviation charter aircraft available to third parties. The Company incurred travel expenses of $0.4 million and $0.3 million during the three months ended March 31, 2018 and 2017, respectively, related to these travel services. These travel expenses are recorded in Selling, general and administrative in the Company’s condensed consolidated statements of operations.

(12) Related Party Transactions

Employee Loans

The Company periodically extends short term loans or advances to employees, typically upon commencement of employment. Total receivables as a result of these employee advances of $0.2 million existed at March 31, 2018 and December 31, 2017, respectively, and are included in the Prepaid expenses and other current assets and Other assets line items of the condensed consolidated balance sheets, respectively, depending on the contractual repayment date.

Service Agreements

Coherus BioSciences, Inc. (“Coherus”)

The chief executive officer of the Company was a member of Coherus’s board of directors until his resignation in the first quarter of 2018. Coherus is no longer considered a related party as of the first quarter of 2018. During the three months ended March 31, 2017, the Company recognized service revenue from Coherus of $3.3 million in the Company’s condensed consolidated statements of operations. In addition, the company recognized Reimbursed out-of-pocket revenue with Coherus in the condensed consolidated statements of operations of $0.6 million during the three months ended March 31, 2017. As of December 31, 2017, the Company had Accounts receivable and unbilled, net from Coherus of $0.3 million recorded in the condensed consolidated balance sheets. As of December 31, 2017, the Company had, from Coherus, $1.5 million of Advanced billings and $1.0 million of Pre-funded study costs, in the condensed consolidated balance sheets.

Xenon Pharmaceuticals, Inc. (“Xenon”)

Certain executives and employees of the Company, including the chief executive officer, have held equity investments in Xenon, a clinical-stage biopharmaceutical company. During the second quarter of 2017, the chief executive officer sold his entire equity position held in Xenon. Xenon is no longer considered to be a related party subsequent to this sale. The Company recognized service revenue from Xenon of $0.5 million during the three months ended March 31, 2017 in the Company’s condensed consolidated statements of operations.

Cymabay Therapeutics, Inc. (“Cymabay”)

Cymabay is a clinical-stage biopharmaceutical company developing therapies to treat metabolic diseases with high unmet medical need, including serious rare and orphan disorders. During the first quarter of 2016, it was announced that a Medpace employee would join Cymabay’s board of directors. The Company and Cymabay entered into a MSA dated October 21, 2016. Subsequently, the Company and Cymabay have entered into several task orders for the Company to perform clinical trial related services. During the three months ended March 31, 2018, the Company recognized total revenue from Cymabay of $0.7 million and for the three months ended March 31, 2017, the Company recognized service revenue from Cymabay of $0.1 million in the Company’s condensed consolidated statements of operations. As of March 31, 2018 and December 31, 2017, respectively, the Company had Accounts receivable and unbilled, net from Cymabay of $0.6 million and $0.1 million recorded in the condensed consolidated balance sheets. As of March 31, 2018, the Company had, from Cymabay, $0.1 million in Advanced billings.

LIB Therapeutics LLC (“LIB”)

Certain executives and employees of the Company, including the chief executive officer, are members of LIB’s board of managers. The Company entered into a MSA dated November 24, 2015 with LIB, a company that engages in research, development, marketing and commercialization of pharmaceutical drugs. Subsequently, the Company and LIB have entered into several task orders for the Company to perform clinical trial related services. During the three months ended March 31, 2018, the Company recognized total revenue from LIB of $0.8 million and for the three months ended March 31, 2017, the Company recognized service revenue from LIB of $0.1 million, respectively, in the Company’s condensed consolidated statements of operations. As of March 31, 2018 and December 31, 2017, respectively, the Company had Advanced billings from LIB of $0.2 million and $0.2 million recorded in the condensed consolidated balance sheets. In addition, as of March 31, 2018 and December 31, 2017, respectively, the Company had Accounts receivable and unbilled, net from LIB of $0.7 million and $0.5 million recorded in the condensed consolidated balance sheets.

Purchase of Real Estate Properties

In December 2016, the Company entered into a purchase agreement for four parcels of real estate property that are closely situated to the Medpace campus in Cincinnati, Ohio, from AT Redevelopment Company, LLC, which is wholly-owned by the Company’s chief executive officer. The purchase price of the real estate property was $0.4 million as determined by an independent third party broker's opinion of value. The transaction closed on January 11, 2017.

Leased Real Estate

Headquarters Lease

The Company entered into an operating lease for its corporate headquarters with an entity that is wholly owned by the chief executive officer of the Company. The Company has evaluated its relationship with the related party and concluded that the related party is not a variable interest entity because the Company has no direct ownership interest or relationship other than the lease. The lease for headquarters is for an initial term of twelve years through November 2022 with a renewal option for one 10-year term at prevailing market rates. The Company pays rent, taxes, insurance, and maintenance expenses that arise from the use of the property. Annual base rent for the corporate headquarters allows for adjustments to the rental rate annually for increases in the consumer price index. Lease expense recognized for each of the three months ended March 31, 2018 and 2017 was $0.5 million, respectively. The lease expense was allocated between Total direct costs and Selling, general and administrative in the condensed consolidated statements of operations.

Deemed Assets and Deemed Landlord Liabilities

The Company entered into two multi-year lease agreements governing the occupancy of space of two buildings in Cincinnati, Ohio with an entity that is wholly owned by the Company’s chief executive officer and certain members of his immediate family. In accordance with the accounting guidance related to leases, the Company was deemed in substance to be the owner of the property during the construction phase and at completion. Accordingly, the Company reflected the buildings and related liabilities as deemed assets from landlord building construction in Property and equipment, net, Other current liabilities, and Deemed landlord liability, less current portion, respectively, on the condensed consolidated balance sheets. The Company assumed occupancy in 2012 and the leases expire in 2027 with the Company having one 10-year option to extend the lease term. The deemed assets are being fully depreciated, on a straight line basis, over the 15-year term of the lease. Deemed landlord liabilities are recorded at their net present value when the Company enters into qualifying leases and are reduced as the Company makes periodic lease payments on the properties. Accretion expense is being recorded over the term of the lease as a component of Interest expense, net in the Company’s condensed consolidated statements of operations. The Company paid $1.0 million and $0.9 million during the three months ended March 31, 2018 and 2017, respectively. The current and long-term portions of the Deemed landlord liability at March 31, 2018 were $2.0 million and $26.1 million, respectively. The current and long-term portions of the Deemed landlord liability at December 31, 2017 were $1.9 million and $26.6 million, respectively. The Company has recognized deemed assets, net of $15.9 million and $16.3 million at March 31, 2018 and December 31, 2017, respectively, in the condensed consolidated balance sheets.

Travel Services

The Company incurs expenses for travel services for company executives provided by a private aviation charter company that is owned by the chief executive officer and the executive vice president of operations of the Company (“private aviation charter”). The Company may contract directly with the private aviation charter for the use of its aircraft or indirectly through a third party aircraft management and jet charter company (the “Aircraft Management Company”). The travel services provided are primarily for business purposes, with certain personal travel paid for as part of the executives’ compensation arrangements. The Aircraft Management Company also makes the private aviation charter aircraft available to third parties. The Company incurred travel expenses of $0.4 million and $0.3 million during the three months ended March 31, 2018 and 2017, respectively, related to these travel services. These travel expenses are recorded in Selling, general and administrative in the Company’s condensed consolidated statements of operations.