Accumulated Other Comprehensive Income (Changes In The Components Of AOCI) (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Beginning balance	$ (283)	$ 100	$ 115
Other comprehensive income (loss) before reclassifications	32	(391)	(39)
Amounts reclassified from AOCI	112	8	24
Total other comprehensive income (loss)	144	(383)	(15)
Ending balance	(139)	(283)	100
Unrealized gains (losses) on AFS, net [Member]
Beginning balance	(234)	138	176
Other comprehensive income (loss) before reclassifications	33	(362)	(26)
Amounts reclassified from AOCI	67	(10)	(12)
Total other comprehensive income (loss)	100	(372)	(38)
Ending balance	(134)	(234)	138
Foreign current translation, net [Member]
Beginning balance	(4)	(6)	(10)
Other comprehensive income (loss) before reclassifications	0	2	4
Amounts reclassified from AOCI	0	0	0
Total other comprehensive income (loss)	0	2	4
Ending balance	(4)	(4)	(6)
Instrument-specific credit risk of liabilities measured at fair value, net [Member]
Beginning balance	(45)	(32)	(51)
Other comprehensive income (loss) before reclassifications	(1)	(31)	(17)
Amounts reclassified from AOCI	45	18	36
Total other comprehensive income (loss)	44	(13)	19
Ending balance	$ (1)	$ (45)	$ (32)