ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) - Schedule of Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	$ 23,761	$ 24,201	$ 24,342	$ 23,690
Other comprehensive income (loss) before reclassifications	(158)	(744)	(732)	(244)
Amounts reclassified to the Consolidated Statements of Operations	187	124	355	241
Total other comprehensive income (loss), net of income taxes	29	(620)	(377)	(3)
Ending balance	23,869	23,585	23,869	23,585
Total AOCI
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	(4,164)	(3,943)	(3,758)	(4,560)
Total other comprehensive income (loss), net of income taxes	29	(620)	(377)	(3)
Ending balance	(4,135)	(4,563)	(4,135)	(4,563)
Net Unrealized Gains (Losses) on Derivatives
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	(1,343)	(1,149)	(1,087)	(1,416)
Other comprehensive income (loss) before reclassifications	(129)	(505)	(534)	(332)
Amounts reclassified to the Consolidated Statements of Operations	170	101	319	195
Total other comprehensive income (loss), net of income taxes	41	(404)	(215)	(137)
Ending balance	(1,302)	(1,553)	(1,302)	(1,553)
Net Unrealized Gains (Losses) on Debt Securities
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	(2,497)	(2,424)	(2,338)	(2,771)
Other comprehensive income (loss) before reclassifications	(29)	(239)	(202)	88
Amounts reclassified to the Consolidated Statements of Operations	15	20	29	40
Total other comprehensive income (loss), net of income taxes	(14)	(219)	(173)	128
Ending balance	(2,511)	(2,643)	(2,511)	(2,643)
Employee Benefit Plans
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	(324)	(370)	(333)	(373)
Other comprehensive income (loss) before reclassifications	0	0	4	0
Amounts reclassified to the Consolidated Statements of Operations	2	3	7	6
Total other comprehensive income (loss), net of income taxes	2	3	11	6
Ending balance	$ (322)	$ (367)	$ (322)	$ (367)