Investments - BeiGene (Details) - BeiGene - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2020	Jan. 02, 2020
Net Investment Income [Line Items]
Ownership percentage	20.50%	20.50%
Equity Method Investment, Aggregate Cost		$ 2,800
Equity Method Investment, Quoted Market Value	$ 4,900	2,600
Equity Method Investment, Difference Between Carrying Amount and Underlying Equity		$ 2,400
Equity method investment, change in carrying value	569
Equity Method Investment, Change In Carrying Value, Other	34
Company's share of profits (losses) of related party	(229)
Equity Method Investment, Amortization of Difference Between Carrying Amount and Underlying Equity	109
Approximate carrying value of the company's equity method investment	$ 2,900
Minimum [Member]
Net Investment Income [Line Items]
Finite-Lived Intangible Asset, Useful Life	8 years
Maximum [Member]
Net Investment Income [Line Items]
Finite-Lived Intangible Asset, Useful Life	15 years

Equity Method Investment, Amortization of Difference Between Carrying Amount and Underlying Equity

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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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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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Useful life of finite-lived intangible assets, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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