Fair Value Of Financial Instruments (Aggregate Fair Value And Remaining Contractual Principal Balance Outstanding On Fair Value Option) (Detail) - USD ($) $ in Millions	Dec. 31, 2022	Dec. 31, 2021
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	$ 39	$ 40
Loans receivable and other instruments, 90 days or more past due, contractual outstanding principal	149	141
Loans receivable and other instruments, fair value	39	40
Loans receivable and other instruments, 90 days or more past due, fair value	39	37
Loans receivable and other instruments, difference	0	0
Loans receivable and other instruments, 90 days or more past due, difference	110	104
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	188	181
Loans receivable and other instruments, fair value	78	77
Loans receivable and other instruments, difference	110	104
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	780	922
Long-term debt instruments, fair value	172	291
Long-term debt instruments, difference	608	631
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	53	108
Long-term debt instruments, fair value	41	98
Long-term debt instruments, difference	$ 12	$ 10