Identifiable Intangible Assets and Goodwill - Goodwill (Detail) $ in Millions	9 Months Ended
	Oct. 01, 2017 USD ($)
Goodwill [Roll Forward]
Balance, December 31, 2016	$ 54,449	[1]
Additions	664	[2]
Other	966	[3]
Balance, October 1, 2017	56,078	[1]
IH [Member]
Goodwill [Roll Forward]
Balance, December 31, 2016	30,134
Additions	572	[2]
Other	491	[3]
Balance, October 1, 2017	31,197
EH [Member]
Goodwill [Roll Forward]
Balance, December 31, 2016	24,315
Additions	92	[2]
Other	475	[3]
Balance, October 1, 2017	$ 24,882

[1] Amounts may not add due to rounding.

[2] IH additions primarily represent measurement period adjustments related to our Medivation acquisition, and EH additions relate to our acquisition of AstraZeneca’s small molecule anti-infectives business, which are subject to change until we complete the valuation of assets acquired and liabilities assumed (see Note 2A).

[3] Primarily reflects the impact of foreign exchange and an adjustment of our estimate of goodwill associated with the HIS net assets sold.