Financial Instruments - Long-Term Debt (Details) - USD ($) $ in Millions		3 Months Ended	6 Months Ended
		Jun. 28, 2020	Jun. 28, 2020	Jun. 30, 2019	Dec. 31, 2019
Debt Instrument [Line Items]
Net fair value adjustments related to hedging and purchase accounting		$ 1	$ 1		$ 5
Net unamortized discounts, premiums and debt issuance costs		(14)	(14)		(43)
Total long-term debt, carried at historical proceeds, as adjusted	[1],[2]	50,529	50,529		35,955
Current portion of long-term debt, carried at historical proceeds, as adjusted (not included above)	[1]	1,481	1,481		1,462
Proceeds from issuance of long-term debt	[3],[4]		16,606	$ 4,942
Unsecured Debt [Member]
Debt Instrument [Line Items]
Total long-term debt, principal amount	[5]	49,187	49,187		34,820
Net fair value adjustments related to hedging and purchase accounting		1,654	1,654		1,305
Net unamortized discounts, premiums and debt issuance costs		(317)	(317)		(176)
Other long-term debt		5	5		5
Total long-term debt, carried at historical proceeds, as adjusted		50,529	50,529		35,955
Current portion of long-term debt, carried at historical proceeds, as adjusted (not included above)		1,481	1,481		$ 1,462
Subsidiaries [Member] | Upjohn Inc [Member]
Debt Instrument [Line Items]
Proceeds from issuance of long-term debt		$ 11,400	$ 11,400

[1] Amounts may not add due to rounding.

[2] The balance as of June 28, 2020 reflects the Upjohn Inc. and Upjohn Finance B.V. debt issuances. For additional information see Note 7D. Financial Instruments: Long-Term Debt

[3] Amounts may not add due to rounding.

[4] 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).

[5] As of June 28, 2020, $11.4 billion of proceeds from the Upjohn debt transactions are invested in money market funds and included in Restricted short-term investments in the condensed consolidated balance sheet.