ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) - Schedule of Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	$ 24,201	$ 22,074	$ 23,690	$ 23,420
Other comprehensive income (loss) before reclassifications	(744)	(957)	(244)	(2,525)
Amounts reclassified to the Consolidated Statements of Operations	124	(3)	241	(28)
Total other comprehensive income (loss), net of income taxes	(620)	(960)	(3)	(2,553)
Ending balance	23,585	24,328	23,585	24,328
Total AOCI
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	(3,943)	(2,258)	(4,560)	(665)
Total other comprehensive income (loss), net of income taxes	(620)	(960)	(3)	(2,553)
Ending balance	(4,563)	(3,218)	(4,563)	(3,218)
Net Unrealized Gains (Losses) on Derivatives
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	(1,149)	(676)	(1,416)	(161)
Other comprehensive income (loss) before reclassifications	(505)	(178)	(332)	(669)
Amounts reclassified to the Consolidated Statements of Operations	101	(8)	195	(32)
Total other comprehensive income (loss), net of income taxes	(404)	(186)	(137)	(701)
Ending balance	(1,553)	(862)	(1,553)	(862)
Net Unrealized Gains (Losses) on Debt Securities
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	(2,424)	(1,236)	(2,771)	(156)
Other comprehensive income (loss) before reclassifications	(239)	(779)	88	(1,856)
Amounts reclassified to the Consolidated Statements of Operations	20	(1)	40	(4)
Total other comprehensive income (loss), net of income taxes	(219)	(780)	128	(1,860)
Ending balance	(2,643)	(2,016)	(2,643)	(2,016)
Employee Benefit Plans
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	(370)	(346)	(373)	(348)
Other comprehensive income (loss) before reclassifications	0	0	0	0
Amounts reclassified to the Consolidated Statements of Operations	3	6	6	8
Total other comprehensive income (loss), net of income taxes	3	6	6	8
Ending balance	$ (367)	$ (340)	$ (367)	$ (340)