Fair Value Measurements (Level 3 Contingent Purchase Price) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014
Fair Value Measurment, Contingent Purchase Price [Roll Forward]
Balance at beginning of period			$ 140,712mdco_ContingentPurchasePrice
Balance at end of period	154,206mdco_ContingentPurchasePrice		140,712mdco_ContingentPurchasePrice
Fair Value, Measurements, Recurring [Member]
Fair Value Measurment, Contingent Purchase Price [Roll Forward]
Balance at beginning of period			351,134
Balance at end of period	369,552		351,134
Fair Value, Measurements, Recurring [Member] \| Fair Value, Inputs, Level 3 [Member]
Fair Value Measurment, Contingent Purchase Price [Roll Forward]
Balance at beginning of period	351,134	302,363
Fair value of contingent purchase price with respect to Annovation as of February 2, 2015	18,000	0
Fair value adjustment to contingent purchase prices included in net income (loss).	418	2,264
Balance at end of period	$ 369,552	$ 304,627

Noncurrent portion of the fair value, as of the balance sheet date, of potential payments under the contingent consideration arrangements.

No definition available.

+ Details

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- Definition

Amount of increase (decrease) in the value of right to a contingent consideration asset.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 805

-SubTopic 30

-Section 50

-Paragraph 4

-Subparagraph (a)(1)

-URI http://asc.fasb.org/extlink&oid=35744584&loc=d3e7008-128479

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- Definition

Amount of gain (loss) recognized in the income statement for financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 820

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (c)(1)

-URI http://asc.fasb.org/extlink&oid=36462937&loc=d3e19207-110258

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