ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) - Schedule of Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	$ 24,866	$ 23,761	$ 24,254	$ 24,342
Other comprehensive income (loss) before reclassifications	139	(158)	629	(732)
Amounts reclassified to the Consolidated Statements of Operations	163	187	327	355
Total other comprehensive income (loss), net of income taxes	302	29	956	(377)
Ending balance	25,234	23,869	25,234	23,869
Total AOCI
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	(2,941)	(4,164)	(3,595)	(3,758)
Total other comprehensive income (loss), net of income taxes	302	29	956	(377)
Ending balance	(2,639)	(4,135)	(2,639)	(4,135)
Net Unrealized Gains (Losses) on Cash Flow Hedges
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	(569)	(1,343)	(925)	(1,087)
Other comprehensive income (loss) before reclassifications	83	(129)	291	(534)
Amounts reclassified to the Consolidated Statements of Operations	145	170	293	319
Total other comprehensive income (loss), net of income taxes	228	41	584	(215)
Ending balance	(341)	(1,302)	(341)	(1,302)
Net Unrealized Gains (Losses) on Investment Securities
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	(2,074)	(2,497)	(2,369)	(2,338)
Other comprehensive income (loss) before reclassifications	56	(29)	338	(202)
Amounts reclassified to the Consolidated Statements of Operations	17	15	30	29
Total other comprehensive income (loss), net of income taxes	73	(14)	368	(173)
Ending balance	(2,001)	(2,511)	(2,001)	(2,511)
Defined Benefit Plans
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	(298)	(324)	(301)	(333)
Other comprehensive income (loss) before reclassifications	0	0	0	4
Amounts reclassified to the Consolidated Statements of Operations	1	2	4	7
Total other comprehensive income (loss), net of income taxes	1	2	4	11
Ending balance	$ (297)	$ (322)	$ (297)	$ (322)