Summary of significant accounting policies (Policies)	6 Months Ended
Summary of significant accounting policies (Policies)	Jun. 30, 2011
Summary of significant accounting policies [Abstract]
Business	Business Amgen Inc. (including its subsidiaries, referred to as “Amgen,” “the Company,” “we,” “our” or “us”) is a global biotechnology medicines company that discovers, develops, manufactures and markets medicines for grievous illnesses. We concentrate on innovating novel medicines based on advances in cellular and molecular biology and we operate in one business segment, human therapeutics.
Basis of presentation	Basis of presentation The financial information for the three and six months ended June 30, 2011 and 2010 is unaudited but includes all adjustments (consisting of only normal recurring adjustments, unless otherwise indicated), which Amgen considers necessary for a fair presentation of its condensed consolidated results of operations for those periods. Interim results are not necessarily indicative of results for the full fiscal year. The condensed consolidated financial statements should be read in conjunction with our consolidated financial statements and the notes thereto contained in our Annual Report on Form 10-K for the year ended December 31, 2010 and our Quarterly Report on Form 10-Q for the period ended March 31, 2011.
Principles of consolidation	Principles of consolidation The condensed consolidated financial statements include the accounts of Amgen as well as its wholly owned subsidiaries. We do not have any significant interests in any variable interest entities. All material intercompany transactions and balances have been eliminated in consolidation.
Use of estimates	Use of estimates The preparation of condensed consolidated financial statements in conformity with accounting principles generally accepted in the United States (GAAP) requires management to make estimates and assumptions that affect the amounts reported in the condensed consolidated financial statements and accompanying notes. Actual results may differ from those estimates.
Revenue recognition for arrangements with multiple - deliverables	Revenue recognition for arrangements with multiple-deliverables From time to time, we enter into arrangements for the research and development (R&D), manufacture and/or commercialization of products and product candidates. These arrangements may require us to deliver various rights, services and/or goods across the entire life cycle of a product or product candidate, including (i) intellectual property rights/licenses, (ii) R&D services, (iii) manufacturing services and/or (iv) commercialization services. The underlying terms of these arrangements generally provide for consideration to Amgen in the form of non-refundable upfront license payments, R&D and commercial performance milestone payments, cost sharing and/or royalty payments. In October 2009, a new accounting standard was issued that amends the guidance on the accounting for arrangements involving the delivery of more than one element. This standard addresses the determination of the unit(s) of accounting for multiple-element arrangements and how the arrangement’s consideration should be allocated to each unit of accounting. The Company adopted this new accounting standard on a prospective basis for all multiple-element arrangements entered into on or after January 1, 2011 and for any multiple-element arrangements that were entered into prior to January 1, 2011 but materially modified on or after January 1, 2011. Pursuant to the new standard, each required deliverable is evaluated to determine if it qualifies as a separate unit of accounting. For Amgen this determination is generally based on whether the deliverable has “stand-alone value” to the customer. The arrangement’s consideration is then allocated to each separate unit of accounting based on the relative selling price of each deliverable. The estimated selling price of each deliverable is determined using the following hierarchy of values: (i) vendor-specific objective evidence of fair value, (ii) third-party evidence of selling price, and (iii) best estimate of selling price (BESP). The BESP reflects our best estimate of what the selling price would be if the deliverable was regularly sold by us on a stand-alone basis. We expect, in general, to use the BESP for allocating consideration to each deliverable. In general, the consideration allocated to each unit of accounting is then recognized as the related goods or services are delivered, limited to the consideration that is not contingent upon future deliverables. For multiple-element arrangements entered into prior to January 1, 2011 and not materially modified thereafter, we continue to apply our prior accounting policy with respect to such arrangements. Under this policy, in general, revenue from non-refundable, upfront fees related to intellectual property rights/licenses where we have continuing involvement is recognized ratably over the estimated period of ongoing involvement because there is no objective and reliable evidence of fair value for any undelivered item to allow the delivered item to be considered a separate unit of accounting. This requirement with respect to the fair value of undelivered items was eliminated in the newly issued accounting standard. In general, the consideration with respect to the other deliverables is recognized when the goods or services are delivered. Under all of our multiple-element arrangements, consideration associated with at risk substantive performance milestones is recognized as revenue upon the achievement of the related milestone, as defined in the respective agreements. The impact of adopting this new accounting standard is dependent on the terms and conditions of any future arrangement that we may enter into that includes multiple-deliverables, however, its adoption is not expected to have a material impact on our consolidated results of operations or financial position. The primary impact of adopting the new accounting standard is expected to be the earlier recognition of revenue associated with delivering rights to the underlying intellectual property. The adoption of this accounting standard did not have a material impact on our condensed consolidated results of operations for the three and six months ended June 30, 2011 or financial position as of June 30, 2011. Our consolidated results of operations for the year ended December 31, 2010 or financial position as of December 31, 2010 also would not have been materially impacted if the accounting standard had been adopted on January 1, 2010.
Inventories	Inventories Inventories are stated at the lower of cost or market. Cost, which includes amounts related to materials, labor and overhead, is determined in a manner which approximates the first-in, first-out method. Cost also includes the recently enacted Puerto Rico excise tax related to our manufacturing operations in Puerto Rico. The Company capitalizes inventories produced in preparation for product launches when the related product candidates are considered to have a high probability of regulatory approval and the related costs are expected to be recoverable through the products’ commercialization.
Property, plant and equipment, net	Property, plant and equipment, net Property, plant and equipment is recorded at historical cost, net of accumulated depreciation and amortization of $5.5 billion and $5.2 billion as of June 30, 2011 and December 31, 2010, respectively.
Business combinations	Business combinations Business combinations are accounted for using the acquisition method of accounting. Under the acquisition method, assets acquired, including in-process research and development (IPR&D) projects, and liabilities assumed are recorded at their respective fair values as of the acquisition date in our condensed consolidated financial statements. The excess of the fair value of consideration transferred over the fair value of the net assets acquired is recorded as goodwill. Contingent consideration obligations incurred in connection with a business combination are recorded at their fair values on the acquisition date. We revalue these obligations each subsequent reporting period until the related contingencies are resolved and record changes in their fair values in earnings. See Note 2, Acquisitions and Note 10, Fair value measurement.
Recent accounting pronouncements	Recent accounting pronouncements In May 2011, a new accounting standard was issued that amends certain fair value measurement principles, clarifies the application of existing fair value measurement requirements and requires additional disclosures regarding fair value. This new standard is required to be applied prospectively beginning in 2012. The Company is currently evaluating the effect this new accounting standard will have on its consolidated financial statements. In June 2011, a new accounting standard was issued that amends the disclosure requirements for the presentation of other comprehensive income (OCI) in the financial statements, including the elimination of the option to present OCI in the statement of stockholders’ equity. OCI and its components will be required to be presented for both interim and annual periods in a single financial statement, the statement of comprehensive income, or in two separate but consecutive financial statements, consisting of a statement of income followed by a separate statement of OCI. In addition, items that are reclassified from OCI to net income must be presented on the face of the financial statement(s), if material. This new standard is required to be applied retrospectively beginning in 2012.