Accumulated Other Comprehensive Income (Loss) - Changes in AOCI (Parenthetical) (Detail) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Amounts Reclassified Out Of Accumulated Other Comprehensive Income Loss [Abstract]
Gain (loss) from net investment hedging, net of tax	$ (54)	$ 11	$ 30
Gain (loss) from net investment hedging, tax (expense) benefit	$ 17	$ (3)	$ (10)

Amount, after tax, of reclassification from accumulated other comprehensive income (AOCI) of gain (loss) from increase (decrease) in fair value of net investment hedge.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4CCC
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=121590274&loc=SL109998896-113959

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 10A
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=121641772&loc=SL7669646-108580

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration