Income Taxes - Reconciliation of Income Tax Expense Computed Using U.S. Statutory Federal Tax Rate to Actual Income Tax Expense (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Amount
Income tax expense at the U.S. federal statutory tax rate	$ 1,226,000,000	$ 1,836,000,000	$ 1,664,000,000
Research and development tax credit	(138,000,000)	(115,000,000)	(107,000,000)
Foreign derived intangible income deduction	(61,000,000)	0	0
Tax deductible dividends	(59,000,000)	(94,000,000)	(92,000,000)
Excess tax benefits for share-based payment awards	(55,000,000)	(106,000,000)	(152,000,000)
Deferred tax write-down and transition tax	(43,000,000)	1,886,000,000	0
U.S. manufacturing deduction benefit	0	(7,000,000)	(117,000,000)
Tax accounting method change	(61,000,000)	0	0
Other, net	(17,000,000)	(44,000,000)	(103,000,000)
Total income tax expense	$ 792,000,000	$ 3,356,000,000	$ 1,093,000,000
Rate
Income tax expense at the U.S. federal statutory tax rate	21.00%	35.00%	35.00%
Research and development tax credit	(2.40%)	(2.20%)	(2.20%)
Foreign derived intangible income deduction	(1.00%)	(0.00%)	(0.00%)
Tax deductible dividends	(1.00%)	(1.80%)	(1.90%)
Excess tax benefits for share-based payment awards	(0.90%)	(2.00%)	(3.20%)
Deferred tax write-down and transition tax	(0.70%)	35.90%	0.00%
U.S. manufacturing deduction benefit	(0.00%)	(0.10%)	(2.50%)
Tax accounting method change, percent	(1.00%)	0.00%	0.00%
Other, net	(0.40%)	(0.80%)	(2.20%)
Income tax expense	13.60%	64.00%	23.00%