ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) - Schedule of Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	$ 24,342	$ 23,690
Other comprehensive income (loss) before reclassifications	(574)	500
Amounts reclassified to the Consolidated Statements of Operations	168	117
Total other comprehensive income (loss), net of income taxes	(406)	617
Ending balance	23,761	24,201
Total AOCI
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	(3,758)	(4,560)
Total other comprehensive income (loss), net of income taxes	(406)	617
Ending balance	(4,164)	(3,943)
Net Unrealized Gains (Losses) on Derivatives
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	(1,087)	(1,416)
Other comprehensive income (loss) before reclassifications	(405)	173
Amounts reclassified to the Consolidated Statements of Operations	149	94
Total other comprehensive income (loss), net of income taxes	(256)	267
Ending balance	(1,343)	(1,149)
Net Unrealized Gains (Losses) on Debt Securities
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	(2,338)	(2,771)
Other comprehensive income (loss) before reclassifications	(173)	327
Amounts reclassified to the Consolidated Statements of Operations	14	20
Total other comprehensive income (loss), net of income taxes	(159)	347
Ending balance	(2,497)	(2,424)
Employee Benefit Plans
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	(333)	(373)
Other comprehensive income (loss) before reclassifications	4	0
Amounts reclassified to the Consolidated Statements of Operations	5	3
Total other comprehensive income (loss), net of income taxes	9	3
Ending balance	$ (324)	$ (370)