ACCUMULATED OTHER COMPREHENSIVE (LOSS) INCOME - Schedule of Changes in Components of AOCI (Details) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2026	Mar. 31, 2025
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance, shareholders' equity	$ 22,238	$ 22,228
AOCI activity before reclassifications	(155)	249
Amounts reclassified from AOCI to earnings	0	(3)
Other comprehensive (loss) income, net of tax	(155)	246
Ending balance, shareholders' equity	22,048	22,295
Total accumulated other comprehensive (loss) income
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance, shareholders' equity	83	(445)
Other comprehensive (loss) income, net of tax	(155)	246
Ending balance, shareholders' equity	(72)	(199)
Unrealized loss on securities available for sale
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance, shareholders' equity	(137)	(584)
AOCI activity before reclassifications	(139)	239
Amounts reclassified from AOCI to earnings	0	0
Other comprehensive (loss) income, net of tax	(139)	239
Ending balance, shareholders' equity	(276)	(345)
Unrealized loss on securities available for sale transferred to held to maturity
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance, shareholders' equity	(4)	(4)
AOCI activity before reclassifications	0	0
Amounts reclassified from AOCI to earnings	0	0
Other comprehensive (loss) income, net of tax	0	0
Ending balance, shareholders' equity	(4)	(4)
Defined benefit pension items
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance, shareholders' equity	210	135
AOCI activity before reclassifications	(2)	0
Amounts reclassified from AOCI to earnings	0	0
Other comprehensive (loss) income, net of tax	(2)	0
Ending balance, shareholders' equity	208	135
Unrealized gain on cash flow hedge derivatives
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance, shareholders' equity	14	8
AOCI activity before reclassifications	(14)	10
Amounts reclassified from AOCI to earnings	0	(3)
Other comprehensive (loss) income, net of tax	(14)	7
Ending balance, shareholders' equity	$ 0	$ 15

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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Amount after tax, before reclassification adjustments, of other comprehensive income (loss), attributable to parent.

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