FAIR VALUES OF ASSETS AND LIABILITIES - Balance Sheet Location (Details) - USD ($) $ in Millions		Mar. 31, 2026	Dec. 31, 2025
Financial Assets
Fair Value		$ 35,557	$ 26,132
Held-to-maturity securities		14,768	15,258
Loans held for sale		1,073	1,415
Net loans and leases	[1]	185,575	147,105
Derivative assets, gross		561	507
Derivative assets, netting adjustments		(295)	(260)
Derivative assets, net		266	247
Financial Liabilities
Total deposits		223,482	176,610
Short-term borrowings		1,875	1,261
Long-term borrowings	[1]	21,594	17,221
Derivative liabilities, gross		572	519
Derivative liabilities, netting adjustments		(175)	(169)
Derivative liabilities, net		397	350
Time deposits in excess of the FDIC insurance coverage limit		4,200	2,100
Level 1
Financial Assets
Fair Value		8,486	4,635
Derivative assets, gross		0	0
Financial Liabilities
Derivative liabilities, gross		0	0
Level 2
Financial Assets
Fair Value		22,781	17,389
Derivative assets, gross		551	499
Financial Liabilities
Derivative liabilities, gross		568	514
Level 3
Financial Assets
Fair Value		4,290	4,108
Derivative assets, gross		10	8
Financial Liabilities
Derivative liabilities, gross		4	5
Reported Value Measurement
Financial Assets
Cash and short-term assets		19,675	14,078
Trading account securities		199	63
Fair Value		35,557	26,132
Held-to-maturity securities		14,768	15,258
Other securities		1,281	994
Loans held for sale		1,073	1,415
Net loans and leases		185,575	147,105
Derivative assets, net		266	247
Assets held in trust for deferred compensation plans		212	216
Financial Liabilities
Total deposits		223,482	176,610
Short-term borrowings		1,875	1,261
Long-term borrowings		21,594	17,221
Derivative liabilities, net		397	350
Estimate of Fair Value Measurement
Financial Assets
Cash and short-term assets		19,675	14,078
Trading account securities		199	63
Fair Value		35,557	26,132
Held-to-maturity securities		13,090	13,636
Other securities		1,281	994
Loans held for sale		1,073	1,420
Net loans and leases		184,648	146,273
Derivative assets, netting adjustments		(295)	(260)
Derivative assets, net		266	247
Assets held in trust for deferred compensation plans		212	216
Other securities		64	42
Financial Liabilities
Total deposits		223,471	176,610
Short-term borrowings		1,875	1,261
Long-term borrowings		21,760	17,479
Derivative liabilities, netting adjustments		(175)	(169)
Derivative liabilities, net		397	350
Estimate of Fair Value Measurement | Level 1
Financial Assets
Trading account securities		30	0
Fair Value		8,486	4,635
Held-to-maturity securities		2,163	2,368
Loans held for sale		0	0
Net loans and leases		0	0
Derivative assets, gross		0	0
Other securities		29	30
Financial Liabilities
Total deposits		0	0
Short-term borrowings		261	131
Long-term borrowings		0	0
Derivative liabilities, gross		0	0
Estimate of Fair Value Measurement | Level 2
Financial Assets
Trading account securities		169	63
Fair Value		22,781	17,389
Held-to-maturity securities		10,927	11,268
Loans held for sale		1,068	885
Net loans and leases		105	105
Derivative assets, gross		551	499
Other securities		35	12
Financial Liabilities
Total deposits		193,967	158,472
Short-term borrowings		1,614	1,130
Long-term borrowings		13,975	12,336
Derivative liabilities, gross		568	514
Estimate of Fair Value Measurement | Level 3
Financial Assets
Trading account securities		0	0
Fair Value		4,290	4,108
Held-to-maturity securities		0	0
Loans held for sale		5	535
Net loans and leases		184,543	146,168
Derivative assets, gross		10	8
Other securities		0	0
Financial Liabilities
Total deposits		29,504	18,138
Short-term borrowings		0	0
Long-term borrowings		7,785	5,143
Derivative liabilities, gross		4	5
Amortized Cost | Reported Value Measurement
Financial Assets
Cash and short-term assets		19,675	14,078
Held-to-maturity securities		14,768	15,258
Other securities		1,217	952
Net loans and leases		185,409	146,938
Financial Liabilities
Total deposits		223,482	176,610
Short-term borrowings		1,592	1,123
Long-term borrowings		20,160	16,060
Lower of Cost or Market | Reported Value Measurement
Financial Assets
Loans held for sale		5	530
Fair Value or Fair Value Option | Reported Value Measurement
Financial Assets
Trading account securities		199	63
Fair Value		35,557	26,132
Other securities		64	42
Loans held for sale		1,068	885
Net loans and leases		166	167
Derivative assets, net		266	247
Assets held in trust for deferred compensation plans		212	216
Financial Liabilities
Short-term borrowings		283	138
Long-term borrowings		1,434	1,161
Derivative liabilities, net		$ 397	$ 350

[1] Includes VIE balances in net loans and leases, other assets, long-term debt, and other liabilities of $576 million, $421 million, $512 million, and $147 million, respectively, at March 31, 2026, and $669 million, $431 million, $600 million, and $152 million, respectively, at December 31, 2025. See Note 16 - “Variable Interest Entities” for additional information.