Consolidated Statements of Operations (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
Mar. 31, 2015	Mar. 31, 2014
Income Statement [Abstract]
Collaboration revenue	$ 129,188mdvn_CollaborationRevenue	$ 87,189mdvn_CollaborationRevenue
Operating expenses:
Research and development expenses	44,676us-gaap_ResearchAndDevelopmentExpense	45,919us-gaap_ResearchAndDevelopmentExpense
Selling, general and administrative expenses	83,939	49,735
Total operating expenses	128,615us-gaap_OperatingExpenses	95,654us-gaap_OperatingExpenses
Income (loss) from operations	573us-gaap_OperatingIncomeLoss	(8,465)us-gaap_OperatingIncomeLoss
Other income (expense), net:
Interest expense	(5,608)us-gaap_InterestExpenseDebt	(5,230)us-gaap_InterestExpenseDebt
Interest income	11us-gaap_InvestmentIncomeInterest	9us-gaap_InvestmentIncomeInterest
Other income (expense), net	126us-gaap_OtherNonoperatingIncomeExpense	(38)us-gaap_OtherNonoperatingIncomeExpense
Total other income (expense), net	(5,471)us-gaap_NonoperatingIncomeExpense	(5,259)us-gaap_NonoperatingIncomeExpense
Loss before income tax benefit	(4,898)	(13,724)
Income tax benefit	1,780us-gaap_IncomeTaxExpenseBenefit	59us-gaap_IncomeTaxExpenseBenefit
Net loss	$ (3,118)us-gaap_NetIncomeLoss	$ (13,665)us-gaap_NetIncomeLoss
Basic and diluted net loss per common share	$ (0.04)us-gaap_EarningsPerShareBasicAndDiluted	$ (0.18)us-gaap_EarningsPerShareBasicAndDiluted
Weighted average common shares used in the calculation of basic and diluted net loss per common share	78,318	76,245

Revenues earned from collaboration partners under collaboration agreements.

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The amount of net income or loss for the period per each share in instances when basic and diluted earnings per share are the same amount and reported as a single line item on the face of the financial statements. Basic earnings per share is the amount of net income or loss for the period per each share of common stock or unit outstanding during the reporting period. Diluted earnings per share includes the amount of net income or loss for the period available to each share of common stock or common unit outstanding during the reporting period and to each share or unit that would have been outstanding assuming the issuance of common shares or units for all dilutive potential common shares or units outstanding during the reporting period.

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This element represents the income or loss from continuing operations attributable to the economic entity which may also be defined as revenue less expenses from ongoing operations, after income or loss from equity method investments, but before income taxes, extraordinary items, and noncontrolling interest.

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Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

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Amount of the cost of borrowed funds accounted for as interest expense for debt.

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Amount before accretion (amortization) of purchase discount (premium) of interest income on nonoperating securities.

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The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

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The aggregate amount of income or expense from ancillary business-related activities (that is to say, excluding major activities considered part of the normal operations of the business).

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Generally recurring costs associated with normal operations except for the portion of these expenses which can be clearly related to production and included in cost of sales or services. Includes selling, general and administrative expense.

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The net result for the period of deducting operating expenses from operating revenues.

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The net amount of other income and expense amounts, the components of which are not separately disclosed on the income statement, resulting from ancillary business-related activities (that is, excluding major activities considered part of the normal operations of the business) also known as other nonoperating income (expense) recognized for the period. Such amounts may include: (a) dividends, (b) interest on securities, (c) net gains or losses on securities, (d) unusual costs, (e) gains or losses on foreign exchange transactions, and (f) miscellaneous other income and expense items.

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The aggregate costs incurred (1) in a planned search or critical investigation aimed at discovery of new knowledge with the hope that such knowledge will be useful in developing a new product or service, a new process or technique, or in bringing about a significant improvement to an existing product or process; or (2) to translate research findings or other knowledge into a plan or design for a new product or process or for a significant improvement to an existing product or process whether intended for sale or the entity's use, during the reporting period charged to research and development projects, including the costs of developing computer software up to the point in time of achieving technological feasibility, and costs allocated in accounting for a business combination to in-process projects deemed to have no alternative future use.

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The aggregate total costs related to selling a firm's product and services, as well as all other general and administrative expenses. Direct selling expenses (for example, credit, warranty, and advertising) are expenses that can be directly linked to the sale of specific products. Indirect selling expenses are expenses that cannot be directly linked to the sale of specific products, for example telephone expenses, Internet, and postal charges. General and administrative expenses include salaries of non-sales personnel, rent, utilities, communication, etc.

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Average number of shares or units issued and outstanding that are used in calculating basic and diluted earnings per share (EPS).

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