Income Taxes - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2020	Mar. 31, 2019
Income Tax Contingency [Line Items]
Effective tax rate (percent)	13.70%	9.20%
Excess tax benefits from stock compensation	$ 40
Decrease to tax positions	23
Overall increase (decrease) in unrecognized tax benefits (UTPs)	(28)
Net of Federal Tax
Income Tax Contingency [Line Items]
Overall increase (decrease) in unrecognized tax benefits (UTPs)	$ (29)

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

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Amount of difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying domestic federal statutory income tax rate to pretax income (loss) from continuing operation, attributable to expense for award under share-based payment arrangement. Excludes expense determined to be nondeductible upon grant or after for 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.

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Amount of increase (decrease) to previously recorded tax expense. Includes, but is not limited to, significant settlements of income tax disputes, and unusual tax positions or infrequent actions taken by the entity, including tax assessment reversal, and IRS tax settlement.

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Amount of increase (decrease) in unrecognized tax benefits attributable to uncertain tax positions taken in tax returns.

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