ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) - Schedule of Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	$ 24,254	$ 24,342
Other comprehensive income (loss) before reclassifications	490	(574)
Amounts reclassified to the Consolidated Statements of Operations	164	168
Total other comprehensive income (loss), net of income taxes	654	(406)
Ending balance	24,866	23,761
Total AOCI
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	(3,595)	(3,758)
Total other comprehensive income (loss), net of income taxes	654	(406)
Ending balance	(2,941)	(4,164)
Net Unrealized Gains (Losses) on Cash Flow Hedges
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	(925)	(1,087)
Other comprehensive income (loss) before reclassifications	208	(405)
Amounts reclassified to the Consolidated Statements of Operations	148	149
Total other comprehensive income (loss), net of income taxes	356	(256)
Ending balance	(569)	(1,343)
Net Unrealized Gains (Losses) on Investment Securities
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	(2,369)	(2,338)
Other comprehensive income (loss) before reclassifications	282	(173)
Amounts reclassified to the Consolidated Statements of Operations	13	14
Total other comprehensive income (loss), net of income taxes	295	(159)
Ending balance	(2,074)	(2,497)
Defined Benefit Plans
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	(301)	(333)
Other comprehensive income (loss) before reclassifications	0	4
Amounts reclassified to the Consolidated Statements of Operations	3	5
Total other comprehensive income (loss), net of income taxes	3	9
Ending balance	$ (298)	$ (324)