Income Taxes - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Income Tax Contingency [Line Items]
Effective tax rate	26.00%	18.60%	23.90%	20.50%
Reduction to provision for income taxes for tax credits			$ 28
Provision for tax benefits related to settlement of employee awards	$ 3	$ 23	56	$ 119
Liability for unrecognized tax benefits	540		540		$ 435
Unrecognized tax benefits, accrued interest	56		56		48
Unrecognized tax benefits that would impact effective tax rate	147		147		$ 137
Provision for income taxes	$ 215	$ 173	$ 765	$ 702

Unrecognized tax benefits including interest accrued net of deferred tax assets.

No definition available.

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- Definition

Percentage of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

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Amount of tax benefit for recognition of expense of award under share-based payment arrangement.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

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Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

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Amount of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to tax credits. Including, but not limited to, research credit, foreign tax credit, investment tax credit, and other tax credits.

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Amount of interest expense accrued for an underpayment of income taxes.

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The total amount of unrecognized tax benefits that, if recognized, would affect the effective tax rate.

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