Related party transactions	12 Months Ended
Dec. 31, 2017
Related Party Transactions [Abstract]
Related party transactions	Related party transactions As of December 31, 2017 and 2016, we owned a 50% interest in K-A, a corporation formed in 1984 with Kirin Holdings Company, Limited (Kirin) for the development and commercialization of certain products based on advanced biotechnology. All of our rights to manufacture and market certain products including pegfilgrastim, granulocyte colony-stimulating factor, darbepoetin alfa, recombinant human erythropoietin and romiplostim are pursuant to exclusive licenses from K-A, which we currently market under the brand names Neulasta^®, NEUPOGEN^®/GRANULOKINE^®, Aranesp^®, EPOGEN^® and Nplate^®, respectively. On October 30, 2017, we announced that we agreed to acquire the remaining 50% ownership of K-A from Kirin. The transaction will be accounted for as a business combination and was completed in the first quarter of 2018, making K-A a wholly owned subsidiary of Amgen. See Note 21, Subsequent event. Prior to the closing of the share acquisition, we accounted for our interest in K-A using the equity method and included our share of K-A’s profits or losses in Selling, general and administrative expense in the Consolidated Statements of Income. For the years ended December 31, 2017, 2016 and 2015, our share of K-A’s profits was $68 million, $58 million and $65 million, respectively. The carrying value of our equity method investment in K-A was $570 million and $501 million as of December 31, 2017 and 2016, respectively, and is included in Other assets in the Consolidated Balance Sheets. K-A’s revenues consist of royalty income related to its licensed technology rights. K-A receives royalty income from us, as well as from Kirin and Johnson & Johnson (J&J) under separate product license contracts for certain geographic areas outside the United States. During the years ended December 31, 2017, 2016 and 2015, K-A earned royalties from us of $221 million, $239 million and $264 million, respectively. These amounts are included in Cost of sales in the Consolidated Statements of Income. K-A’s expenses consist primarily of costs related to R&D activities conducted on its behalf by Amgen and Kirin. K-A pays Amgen and Kirin for such services at negotiated rates. During the years ended December 31, 2017, 2016 and 2015, we earned revenues from K-A of $28 million, $31 million and $65 million, respectively, for certain R&D activities performed on K-A’s behalf. These amounts are recognized as Other revenues in the Consolidated Statements of Income. Cost recoveries from K-A recorded during the year ended December 31, 2017 were insignificant. During the years ended December 31, 2016 and 2015, we recorded cost recoveries from K-A of $7 million and $90 million, respectively, related to certain third-party costs. These amounts are included in Research and development expense in the Consolidated Statements of Income. As of December 31, 2017 and 2016, we owed K-A $80 million and $69 million, respectively, which is included in Accrued liabilities in the Consolidated Balance Sheets. Subsequent to the closing of the share acquisition, K-A’s results of operations will be included in our consolidated financial statements, and as a result, transactions between us and K-A will be eliminated in consolidation. License agreements with Kirin and J&J will remain in place.

Related party transactions

As of December 31, 2017 and 2016, we owned a 50% interest in K-A, a corporation formed in 1984 with Kirin Holdings Company, Limited (Kirin) for the development and commercialization of certain products based on advanced biotechnology. All of our rights to manufacture and market certain products including pegfilgrastim, granulocyte colony-stimulating factor, darbepoetin alfa, recombinant human erythropoietin and romiplostim are pursuant to exclusive licenses from K-A, which we currently market under the brand names Neulasta^®, NEUPOGEN^®/GRANULOKINE^®, Aranesp^®, EPOGEN^® and Nplate^®, respectively. On October 30, 2017, we announced that we agreed to acquire the remaining 50% ownership of K-A from Kirin. The transaction will be accounted for as a business combination and was completed in the first quarter of 2018, making K-A a wholly owned subsidiary of Amgen. See Note 21, Subsequent event.

Prior to the closing of the share acquisition, we accounted for our interest in K-A using the equity method and included our share of K-A’s profits or losses in Selling, general and administrative expense in the Consolidated Statements of Income. For the years ended December 31, 2017, 2016 and 2015, our share of K-A’s profits was $68 million, $58 million and $65 million, respectively. The carrying value of our equity method investment in K-A was $570 million and $501 million as of December 31, 2017 and 2016, respectively, and is included in Other assets in the Consolidated Balance Sheets.

K-A’s revenues consist of royalty income related to its licensed technology rights. K-A receives royalty income from us, as well as from Kirin and Johnson & Johnson (J&J) under separate product license contracts for certain geographic areas outside the United States. During the years ended December 31, 2017, 2016 and 2015, K-A earned royalties from us of $221 million, $239 million and $264 million, respectively. These amounts are included in Cost of sales in the Consolidated Statements of Income.

K-A’s expenses consist primarily of costs related to R&D activities conducted on its behalf by Amgen and Kirin. K-A pays Amgen and Kirin for such services at negotiated rates. During the years ended December 31, 2017, 2016 and 2015, we earned revenues from K-A of $28 million, $31 million and $65 million, respectively, for certain R&D activities performed on K-A’s behalf. These amounts are recognized as Other revenues in the Consolidated Statements of Income. Cost recoveries from K-A recorded during the year ended December 31, 2017 were insignificant. During the years ended December 31, 2016 and 2015, we recorded cost recoveries from K-A of $7 million and $90 million, respectively, related to certain third-party costs. These amounts are included in Research and development expense in the Consolidated Statements of Income.

As of December 31, 2017 and 2016, we owed K-A $80 million and $69 million, respectively, which is included in Accrued liabilities in the Consolidated Balance Sheets.

Subsequent to the closing of the share acquisition, K-A’s results of operations will be included in our consolidated financial statements, and as a result, transactions between us and K-A will be eliminated in consolidation. License agreements with Kirin and J&J will remain in place.