Financial Instruments - Financial Assets and Liabilities Measured at Fair Value on a Recurring Basis - Footnotes (Detail) - USD ($) $ in Millions	9 Months Ended
	Sep. 27, 2020	Sep. 29, 2019	Dec. 31, 2019
Footnotes to selected financial assets and liabilities:
Proceeds from issuance of long-term debt	$ 16,700	$ 4,942
Recurring [Member]
Footnotes to selected financial assets and liabilities:
Long-term equity securities held in trust	181		$ 176
Subsidiaries [Member] | Upjohn Inc [Member]
Footnotes to selected financial assets and liabilities:
Proceeds from issuance of long-term debt	$ 11,400