Financial Instruments - Total Short-Term and Long-Term Investments and Equity Method Investments - Footnotes (Details) - USD ($) $ in Millions		3 Months Ended	6 Months Ended
		Jun. 28, 2020	Jun. 28, 2020	Jun. 30, 2019
Debt Securities, Available-for-sale [Line Items]
Proceeds from issuance of long-term debt	[1],[2]		$ 16,606	$ 4,942
Subsidiaries [Member] | Upjohn Inc [Member]
Debt Securities, Available-for-sale [Line Items]
Proceeds from issuance of long-term debt		$ 11,400	$ 11,400

[1] Amounts may not add due to rounding.

[2] Includes $11.4 billion of proceeds from the Upjohn long-term debt issuances in the second quarter of 2020, which are included in Restricted short-term investments in the condensed consolidated balance sheet. For additional information, see Notes 7A. Financial Instruments: Fair Value Measurements and Financial Instruments: 7D. Long-Term Debt).