ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) - Schedule of Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	$ 23,690	$ 23,420	$ 22,673
Total other comprehensive income (loss), net of income taxes	802	(3,895)	(605)
Ending balance	24,342	23,690	23,420
Total AOCI
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	(4,560)	(665)	(60)
Other comprehensive income (loss) before reclassifications	272	(3,985)	(577)
Amounts reclassified to the Consolidated Statements of Operations	530	90	(28)
Total other comprehensive income (loss), net of income taxes	802	(3,895)	(605)
Ending balance	(3,758)	(4,560)	(665)
Net Unrealized Gains (Losses) on Derivatives
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	(1,416)	(161)	(11)
Other comprehensive income (loss) before reclassifications	(106)	(1,340)	(49)
Amounts reclassified to the Consolidated Statements of Operations	435	85	(101)
Total other comprehensive income (loss), net of income taxes	329	(1,255)	(150)
Ending balance	(1,087)	(1,416)	(161)
Net Unrealized Gains (Losses) on Debt Securities
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	(2,771)	(156)	380
Other comprehensive income (loss) before reclassifications	350	(2,608)	(528)
Amounts reclassified to the Consolidated Statements of Operations	83	(7)	(8)
Total other comprehensive income (loss), net of income taxes	433	(2,615)	(536)
Ending balance	(2,338)	(2,771)	(156)
Employee Benefit Plans
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	(373)	(348)	(429)
Other comprehensive income (loss) before reclassifications	28	(37)	0
Amounts reclassified to the Consolidated Statements of Operations	12	12	81
Total other comprehensive income (loss), net of income taxes	40	(25)	81
Ending balance	$ (333)	$ (373)	$ (348)