Income Taxes - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Sep. 30, 2021	Mar. 31, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Income Tax Disclosure [Abstract]
Effective tax rate (percent)	23.40%		22.00%	20.20%	20.00%
Excess tax benefits from stock compensation				$ 29
Reduction resulting from lapse of applicable statute of limitations and settlement				66
Overall increase (decrease) in unrecognized tax benefits (UTPs)	$ 85			9
Overall increase (decrease) in unrecognized tax benefits (UTPs), net of federal tax	$ 84			17
Interest accrued on UTPs		$ 40		$ 40

Benefit related to reversal of accrued interest pursuant to the resolution of uncertain tax positions

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- Definition

Unrecognized Tax Benefits, Period Increase (Decrease), Net of Federal Tax

+ References

No definition available.

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- Definition

Amount of decrease in unrecognized tax benefits resulting from settlements and lapses of applicable statutes of limitations

+ References

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.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 12
-URI http://asc.fasb.org/extlink&oid=121826272&loc=d3e32687-109319

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- Definition

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.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 12
-URI http://asc.fasb.org/extlink&oid=121826272&loc=d3e32687-109319

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 740
-Section 35
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=120384911&loc=d3e23163-113944

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- Definition

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

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 15A
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=121826272&loc=SL6600010-109319

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