Financial Instruments - Other Noncurrent Liabilities (Detail) - USD ($) $ in Millions		1 Months Ended
		Aug. 31, 2017	Jun. 30, 2017	Oct. 01, 2017	Dec. 31, 2016
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, net				$ 37,492	$ 35,664
Developed Technology Rights [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, net	[1]			35,625	$ 33,740
Besponsa [Member] | Developed Technology Rights [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, net				371
U.S. [Member] | Besponsa [Member]
Finite-Lived Intangible Assets [Line Items]
Term over which fixed annual payments are to be made		9 years
Aggregate amount of guaranteed fixed annual payments to be made in connection with research and development arrangement		$ 296
U.S. [Member] | Besponsa [Member] | Developed Technology Rights [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, net				248
U.S. [Member] | Besponsa [Member] | Developed Technology Rights [Member] | Other Noncurrent Liabilities [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, net				233
U.S. [Member] | Besponsa [Member] | Developed Technology Rights [Member] | Other Current Liabilities [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, net				15
EU [Member] | Besponsa [Member]
Finite-Lived Intangible Assets [Line Items]
Term over which fixed annual payments are to be made			9 years
Aggregate amount of guaranteed fixed annual payments to be made in connection with research and development arrangement			$ 148
EU [Member] | Besponsa [Member] | Developed Technology Rights [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, net				123
EU [Member] | Besponsa [Member] | Developed Technology Rights [Member] | Other Noncurrent Liabilities [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, net				117
EU [Member] | Besponsa [Member] | Developed Technology Rights [Member] | Other Current Liabilities [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, net				$ 6

[1] The changes in the gross carrying amount of Developed technology rights and IPR&D primarily reflect (i) the transfer of $4.8 billion from IPR&D to Developed technology rights to reflect the approval of Eucrisa, (ii) the Developed technology rights and IPR&D acquired as part of the acquisition of AstraZeneca’s small molecule anti-infectives business (see Note 2A), (iii) the Developed technology rights of $371 million recorded in connection with the EU and U.S. approvals of Besponsa (see Note 7E), partially offset by (iv) measurement period adjustments related to Medivation (see Note 2A) and (v) impairments of Developed technology rights (see Note 4).