Fair Value Measurements (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Liabilities:
Contingent purchase price	$ 140,712mdco_ContingentPurchasePrice	$ 302,363mdco_ContingentPurchasePrice
Fair Value, Measurements, Recurring [Member]
Assets:
Money market	6,030	45,950
Total assets at fair value	6,030	45,950
Liabilities:
Contingent purchase price	351,134	302,363
Total liabilities at fair value	351,134	302,363
Fair Value, Measurements, Recurring [Member] \| Fair Value, Inputs, Level 1 [Member]
Assets:
Money market	6,030	45,950
Total assets at fair value	6,030	45,950
Liabilities:
Contingent purchase price	0	0
Total liabilities at fair value	0	0
Fair Value, Measurements, Recurring [Member] \| Fair Value, Inputs, Level 2 [Member]
Assets:
Money market	0	0
Total assets at fair value	0	0
Liabilities:
Contingent purchase price	0	0
Total liabilities at fair value	0	0
Fair Value, Measurements, Recurring [Member] \| Fair Value, Inputs, Level 3 [Member]
Assets:
Money market	0	0
Total assets at fair value	0	0
Liabilities:
Contingent purchase price	351,134	302,363	18,971
Total liabilities at fair value	351,134	302,363
Incline Therapeutics, Inc. [Member]
Liabilities:
Contingent purchase price	123,800	115,890
Targanta [Member]
Liabilities:
Contingent purchase price	6,334	5,573
ProFibrix [Member]
Liabilities:
Contingent purchase price	88,600	84,000
Commercial Milestones [Member] \| Rempex [Member]
Liabilities:
Contingent purchase price	80,800	87,900
Sales Milestone [Member] \| Rempex [Member]
Liabilities:
Contingent purchase price	$ 10,900	$ 9,000

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

No definition available.

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- Definition

Fair value portion of probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

+ 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 (a)

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

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- Definition

Fair value portion of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Cash

-URI http://asc.fasb.org/extlink&oid=6506951

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Cash Equivalents

-URI http://asc.fasb.org/extlink&oid=6507016

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- Definition

Fair value of financial and nonfinancial obligations.

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