ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) - AOCI Components Pre Post & Tax Effect (Details) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2026	Mar. 31, 2025
Accumulated Other Comprehensive Income (Loss) [Line Items]
Net unrealized gains (losses), net	$ (224)	$ 490
Reclassification from AOCI, net	106	164
Total other comprehensive income (loss), before tax	(159)	884
Total other comprehensive income (loss), tax	41	(230)
Total other comprehensive income (loss), net	(118)	654
Net unrealized gains (losses) on cash flow hedges
Accumulated Other Comprehensive Income (Loss) [Line Items]
Net unrealized gains (losses), before tax	(169)	284
Net unrealized gains (losses), tax	45	(76)
Net unrealized gains (losses), net	(124)	208
Reclassification from AOCI	113	202
Reclassification from AOCI, tax	(30)	(54)
Reclassification from AOCI, net	83	148
Total other comprehensive income (loss), before tax	(56)	486
Total other comprehensive income (loss), tax	15	(130)
Total other comprehensive income (loss), net	(41)	356
Net unrealized gains (losses) on investment securities
Accumulated Other Comprehensive Income (Loss) [Line Items]
Net unrealized gains (losses), before tax	(133)	377
Net unrealized gains (losses), tax	33	(95)
Net unrealized gains (losses), net	(100)	282
Reclassification from AOCI	25	17
Reclassification from AOCI, tax	(6)	(4)
Reclassification from AOCI, net	19	13
Total other comprehensive income (loss), before tax	(108)	394
Total other comprehensive income (loss), tax	27	(99)
Total other comprehensive income (loss), net	(81)	295
Defined benefit plans
Accumulated Other Comprehensive Income (Loss) [Line Items]
Net unrealized gains (losses), net	0	0
Reclassification from AOCI, net	4	3
Total other comprehensive income (loss), before tax	5	4
Total other comprehensive income (loss), tax	(1)	(1)
Total other comprehensive income (loss), net	4	3
Net actuarial gain (loss) arising during the period
Accumulated Other Comprehensive Income (Loss) [Line Items]
Net unrealized gains (losses), before tax	0	0
Net unrealized gains (losses), tax	0	0
Net unrealized gains (losses), net	0	0
Amortization of actuarial (gain) loss to earnings
Accumulated Other Comprehensive Income (Loss) [Line Items]
Reclassification from AOCI	5	4
Reclassification from AOCI, tax	(1)	(1)
Reclassification from AOCI, net	$ 4	$ 3

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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