Derivative Instruments - FV Gains and Losses (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Derivative Instruments, Gain (Loss) [Line Items]
Total derivatives fair value gains, net	$ 514	$ 2,991	$ 558
Net contractual interest income (expense) on interest-rate swaps	$ 28,773	$ 29,423	$ 29,587
Derivative Gain Loss Statement Of Income Or Comprehensive Income Extensible Enumeration Not Disclosed Flag	Total derivatives fair value gains, net	Total derivatives fair value gains, net	Total derivatives fair value gains, net
Pay-fixed
Derivative Instruments, Gain (Loss) [Line Items]
Total derivatives fair value gains, net	$ (1,441)	$ 5,541	$ 2,207
Receive-fixed
Derivative Instruments, Gain (Loss) [Line Items]
Total derivatives fair value gains, net	2,441	(4,788)	(1,783)
Basis
Derivative Instruments, Gain (Loss) [Line Items]
Total derivatives fair value gains, net	39	(143)	(51)
Foreign currency
Derivative Instruments, Gain (Loss) [Line Items]
Total derivatives fair value gains, net	32	(87)	(26)
Pay-fixed swaption
Derivative Instruments, Gain (Loss) [Line Items]
Total derivatives fair value gains, net	(2)	142	38
Receive-fixed swaption
Derivative Instruments, Gain (Loss) [Line Items]
Total derivatives fair value gains, net	(10)	(19)	(217)
Futures
Derivative Instruments, Gain (Loss) [Line Items]
Total derivatives fair value gains, net	0	(1)	1
Risk management derivatives
Derivative Instruments, Gain (Loss) [Line Items]
Total derivatives fair value gains, net	348	380	185
Net contractual interest income (expense) on interest-rate swaps	(711)	(265)	16
Mortgage commitment derivatives fair value gains, net
Derivative Instruments, Gain (Loss) [Line Items]
Total derivatives fair value gains, net	120	2,708	551
Credit enhancement derivatives fair value gains (losses), net
Derivative Instruments, Gain (Loss) [Line Items]
Total derivatives fair value gains, net	$ 46	$ (97)	$ (178)