Receivables (Detail) - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Broker-Dealer [Abstract]
Deposit for Canadian retirement accounts	$ 444	$ 412
Fees from mutual funds and insurance companies	377	343	$ 328
Other receivables	146	136
Total	$ 967	$ 891

Amount due from parties in nontrade transactions, classified as other.

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 49
-Publisher FASB
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Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 210
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.6-04(5)(a)(5))
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Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 210
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-Name Accounting Standards Codification
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Reference 4: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 944
-SubTopic 210
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
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-Publisher FASB
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Name:	us-gaap_OtherReceivables
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant