Income Tax Expense Reconciliation (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Tax Expense Reconciliation
Income tax expense at U.S. statutory rate	$ 1,734	$ 150	$ 174
Retained shares tax free exchange gains	(1,587)
Tax incentives	(126)	(133)	(105)
State and local taxes	1	(13)	(24)
Foreign tax expense (benefit)	5	11	(16)
Valuation allowances	3	5	7
Contingent tax matters	(48)	9	(18)
Branded Prescription Drug Fee	1	1	4
Deferred tax charge on intangible intra-group transfers	13	14	14
R&D tax credit	(2)	(4)	(1)
Puerto Rico excise tax credit	(5)	(9)
Other factors	(1)	4	(2)
Income tax (benefit) expense	$ (12)	$ 35	$ 33