Segment Information (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
Mar. 31, 2013	Mar. 31, 2012
Revenue	$ 5,602.0	$ 5,602.0
Segment Reporting Information, Income (Loss) before Income Taxes	1,951.1	1,335.3
Income related to transfer of exenatide rights	495.4	0
Asset impairments, restructuring, and other special charges	(21.7)	(23.8)
Neuroscience [Member]
Segment Reporting Information, Revenue	1,848.8	1,903.7
Endocrinology [Member]
Segment Reporting Information, Revenue	1,724.9	1,690.9
Oncology [Member]
Segment Reporting Information, Revenue	764.2	803.9
Cardiovascular [Member]
Segment Reporting Information, Revenue	693.9	638.4
Animal health [Member]
Segment Reporting Information, Income (Loss) before Income Taxes	129.2	127.4
Segment Reporting Information, Revenue	499.1	490.7
Other pharmaceuticals [Member]
Segment Reporting Information, Revenue	71.1	74.4
Pharmaceutical products, total [Member]
Segment Reporting Information, Income (Loss) before Income Taxes	1,348.2	1,231.7
Segment Reporting Information, Revenue	5,102.9	5,111.3
Total segment [Member]
Segment Reporting Information, Income (Loss) before Income Taxes	1,477.4	1,359.1
Amylin [Member]
Income related to transfer of exenatide rights	$ 495.4	$ 0

Gain (loss) related to the termination of a contract between the parties. The termination may be due to many causes including early termination of a lease by a lessee, a breach of contract by one party, or a failure to perform.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 28

-URI http://asc.fasb.org/extlink&oid=6943989&loc=d3e3602-108585

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 420

-SubTopic 10

-Section 50

-Paragraph 1

-Subparagraph (b)(1)

-URI http://asc.fasb.org/extlink&oid=6394359&loc=d3e17939-110869

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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.

+ References

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 10

-Article 5

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- Definition

The aggregate amount provided for estimated restructuring charges, remediation costs, and asset impairment loss during an accounting period. Generally, these items are either unusual or infrequent, but not both (in which case they would be extraordinary items).

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Aggregate revenue recognized during the period (derived from goods sold, services rendered, insurance premiums, or other activities that constitute an entity's earning process). For financial services companies, also includes investment and interest income, and sales and trading gains.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 225

-SubTopic 10

-Section S99

-Paragraph 2

-Subparagraph (SX 210.5-03.1)

-URI http://asc.fasb.org/extlink&oid=6880815&loc=d3e20235-122688

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

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-Name Regulation S-X (SX)

-Number 210

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Amount of total revenue for the reportable segments, including revenue from external customers, transactions with other operating segments of the same entity, and (gross) interest revenue. All considered to be "operating revenue" for purposes of the taxonomy.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 280

-SubTopic 10

-Section 50

-Paragraph 22

-Subparagraph (a),(b),(c)

-URI http://asc.fasb.org/extlink&oid=6534315&loc=d3e8736-108599

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 131

-Paragraph 27

-Subparagraph a, b, c

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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