Fair Value of Financial Instruments (Aggregate Fair Value And Remaining Contractual Principal Balance Outstanding On Fair Value Option) (Detail) - USD ($) $ in Millions	Jun. 30, 2025	Dec. 31, 2024
Residential Mortgage Loans [Member] \| Loans Receivable [Member]
Schedule Of Fair Value Of Separate Accounts By Major Category Of Investment [Line Items]
Loans receivable and other instruments, contractual outstanding principal	$ 13	$ 12
Loans receivable and other instruments, 90 days or more past due, contractual outstanding principal	53	48
Loans receivable and other instruments, fair value	13	12
Loans receivable and other instruments, 90 days or more past due, fair value	20	16
Loans receivable and other instruments, difference	0	0
Loans receivable and other instruments, 90 days or more past due, difference	33	32
Corporate Loans - Current [Member] \| Loans Receivable [Member]
Schedule Of Fair Value Of Separate Accounts By Major Category Of Investment [Line Items]
Loans receivable and other instruments, contractual outstanding principal	18	16
Loans receivable and other instruments, fair value	15	15
Loans receivable and other instruments, difference	3	1
Total Loans Receivable and Other Instruments [Member] \| Loans Receivable [Member]
Schedule Of Fair Value Of Separate Accounts By Major Category Of Investment [Line Items]
Loans receivable and other instruments, contractual outstanding principal	84	76
Loans receivable and other instruments, fair value	48	43
Loans receivable and other instruments, difference	36	33
Variable Interest Entity Notes [Member]
Schedule Of Fair Value Of Separate Accounts By Major Category Of Investment [Line Items]
Long-term debt instruments, contractual outstanding principal	40	45
Long-term debt instruments, fair value	26	31
Long-term debt instruments, difference	14	14
Medium Term Notes [Member]
Schedule Of Fair Value Of Separate Accounts By Major Category Of Investment [Line Items]
Long-term debt instruments, contractual outstanding principal	59	52
Long-term debt instruments, fair value	38	35
Long-term debt instruments, difference	$ 21	$ 17

Fair Value Option Aggregate Fair Value Loans Receivable

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- Definition

Fair Value Option Aggregate Fair Value Long Term Debt Instruments

+ References

No definition available.

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- Definition

Fair Value Option Contractual Outstanding Principal Loans Receivable

+ References

No definition available.

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- Definition

Fair Value Option Contractual Outstanding Principal Loans Receivable 90 Days or More Past Due

+ References

No definition available.

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- Definition

Fair Value Option Contractual Outstanding Principal Long-Term Debt Instruments

+ References

No definition available.

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- Definition

This item represents the difference between the aggregate fair value and the aggregate unpaid principal balance of loans and long-term receivables (other than securities categorized as trading, available-for-sale or held-to-maturity) that have contractual principal amounts and for which the fair value option has been elected.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 28
-Subparagraph (d)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482907/825-10-50-28

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- Definition

This item represents the difference between the aggregate fair value and the aggregate unpaid principal balance of long-term debt instruments that have contractual principal amounts and for which the fair value option has been elected.

+ References

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-SubTopic 10
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- Definition

This item represents the aggregate fair value of loans held as assets that are 90 days or more past due for which the fair value option has been elected.

+ References

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-Name Accounting Standards Codification
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- Definition

For loans held as assets for which the fair value option has been elected, this item represents the difference between the aggregate fair value and the aggregate unpaid principal balance of those loans that are 90 days or more past due.

+ References

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-Section 50
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- Definition

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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-Topic 944
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