Biogen share of co-promotion profits or losses

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- Definition

Collaboration profit (loss) sharing

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- Definition

Equity Method Investment, Ownership Percentage Before Additional Purchase Transaction

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No definition available.

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- Definition

Equity method investment basis difference amortization period

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No definition available.

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- Definition

The aggregate amount of recurring noncash expense charged against earnings in the period to allocate the cost of assets over their estimated remaining economic lives.

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- Definition

Difference between amount at which an investment accounted for under the equity method of accounting is carried (reported) on the balance sheet and amount of underlying equity in net assets the reporting Entity has in the investee.

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- Definition

The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting.

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This item represents the carrying amount on the entity's balance sheet of its investment in common stock of an equity method investee. This is not an indicator of the fair value of the investment, rather it is the initial cost adjusted for the entity's share of earnings and losses of the investee, adjusted for any distributions (dividends) and other than temporary impairment (OTTI) losses recognized.

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Amount of income (loss) for proportionate share of equity method investee's income (loss).

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This element represents the undistributed income (or loss) of equity method investments, net of dividends or other distributions received from unconsolidated subsidiaries, certain corporate joint ventures, and certain noncontrolled corporations; such investments are accounted for under the equity method of accounting. This element excludes distributions that constitute a return of investment, which are classified as investing activities.

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The cash outflow associated with the purchase of or advances to an equity method investments, which are investments in joint ventures and entities in which the entity has an equity ownership interest normally of 20 to 50 percent and exercises significant influence.

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Amount of revenue recognized from goods sold, services rendered, insurance premiums, or other activities that constitute an earning process. Includes, but is not limited to, investment and interest income before deduction of interest expense when recognized as a component of revenue, and sales and trading gain (loss).

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Collaborative and Other Relationships - Equity Method Investments (Details) $ in Millions, ₩ in Billions	3 Months Ended				6 Months Ended
	Jun. 30, 2019 USD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2018 KRW (₩)	Jun. 30, 2018 USD ($)	Jun. 30, 2019 USD ($)	Jun. 30, 2018 USD ($)	Jun. 30, 2019 KRW (₩)	Dec. 31, 2018 KRW (₩)	Nov. 07, 2018 USD ($)	Sep. 30, 2018
Schedule of Equity Method Investments [Line Items]
Our share of Samsung Bioepis gains (losses)	$ 16.3			$ 0.0	$ 45.0	$ 0.0
Collaboration profit (loss) sharing	63.5			39.2	121.6	81.7
Total revenues	$ 3,616.7			3,356.5	$ 7,106.5	6,487.6
Samsung Bioepis
Schedule of Equity Method Investments [Line Items]
Percentage of stake in entity										5.00%
Percentage of stake in entity maximum	49.90%				49.90%		49.90%
Payments to acquire additional investment in equity method investment		$ 676.6	₩ 759.5
Amortization of basis differences									$ 675.0
Loss recorded on Samsung Bioepis joint venture	$ 16.3				$ 45.0
Our share of Samsung Bioepis gains (losses)	(5.5)				8.5
Amortization of basis differences	21.8				36.5
Investment in Samsung Bioepis	615.5	$ 680.6			$ 615.5		₩ 712.8	₩ 759.5
Biogen share of co-promotion profits or losses					50.00%
Collaboration profit (loss) sharing	63.4			39.7	$ 121.5	83.5
Collaborative arrangement \| Samsung Bioepis
Schedule of Equity Method Investments [Line Items]
Total revenues	$ 52.2			$ 14.7	$ 77.0	$ 32.6
Inventory \| Samsung Bioepis
Schedule of Equity Method Investments [Line Items]
Amortization of basis differences									115.0
Equity method investment basis difference amortization period					1 year 6 months
Developed technology \| Samsung Bioepis
Schedule of Equity Method Investments [Line Items]
Amortization of basis differences									615.0
Equity method investment basis difference amortization period					15 years
In Process Research and Development \| Samsung Bioepis
Schedule of Equity Method Investments [Line Items]
Amortization of basis differences									170.0
Deferred tax liability \| Samsung Bioepis
Schedule of Equity Method Investments [Line Items]
Amortization of basis differences									$ 225.0