FAIR VALUE MEASUREMENTS - Schedule of Fair Value Measurements (Details) - USD ($) $ in Millions		Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Assets
Debt securities available for sale	[1]	$ 35,697	$ 32,765
Loans held for sale at fair value		1,065	825
Mortgage servicing rights		1,455	1,491
Total derivative assets		1,532	1,476
Equity securities, at fair value		251	162
Short-term investments		72	53
Total assets		40,072	36,772
Liabilities
Total derivative liabilities		1,258	1,710
Short-term borrowed funds		52	0
Other liabilities		157	101
Total liabilities		1,467	1,811
Equity securities, at fair value		317	220
Mortgage-backed securities
Assets
Debt securities available for sale		32,484	29,055
Collateralized loan obligations
Assets
Debt securities available for sale		89	184
State and political subdivisions
Assets
Debt securities available for sale		1	1
U.S. Treasury and other
Assets
Debt securities available for sale		3,123	3,525
Residential loans held for sale
Assets
Loans held for sale at fair value		895	633
Commercial loans held for sale
Assets
Loans held for sale at fair value		170	192
Mortgage Servicing Rights
Assets
Mortgage servicing rights		1,455	1,491	$ 1,552
Interest rate contracts
Assets
Total derivative assets		553	562
Liabilities
Total derivative liabilities		471	910
Foreign exchange contracts
Assets
Total derivative assets		510	472
Liabilities
Total derivative liabilities		373	411
Commodities contracts
Assets
Total derivative assets		458	429
Liabilities
Total derivative liabilities		405	379
TBA contracts
Assets
Total derivative assets		2	10
Liabilities
Total derivative liabilities		6	8
Other contracts
Assets
Total derivative assets		9	3
Liabilities
Total derivative liabilities		3	2
Level 1
Assets
Debt securities available for sale		3,123	3,525
Loans held for sale at fair value		0	0
Total derivative assets		0	0
Equity securities, at fair value		251	162
Short-term investments		40	40
Total assets		3,414	3,727
Liabilities
Total derivative liabilities		0	0
Short-term borrowed funds		40	0
Other liabilities		0	0
Total liabilities		40	0
Level 1 | Mortgage-backed securities
Assets
Debt securities available for sale		0	0
Level 1 | Collateralized loan obligations
Assets
Debt securities available for sale		0	0
Level 1 | State and political subdivisions
Assets
Debt securities available for sale		0	0
Level 1 | U.S. Treasury and other
Assets
Debt securities available for sale		3,123	3,525
Level 1 | Residential loans held for sale
Assets
Loans held for sale at fair value		0	0
Level 1 | Commercial loans held for sale
Assets
Loans held for sale at fair value		0	0
Level 1 | Mortgage Servicing Rights
Assets
Mortgage servicing rights		0	0
Level 1 | Interest rate contracts
Assets
Total derivative assets		0	0
Liabilities
Total derivative liabilities		0	0
Level 1 | Foreign exchange contracts
Assets
Total derivative assets		0	0
Liabilities
Total derivative liabilities		0	0
Level 1 | Commodities contracts
Assets
Total derivative assets		0	0
Liabilities
Total derivative liabilities		0	0
Level 1 | TBA contracts
Assets
Total derivative assets		0	0
Liabilities
Total derivative liabilities		0	0
Level 1 | Other contracts
Assets
Total derivative assets		0	0
Liabilities
Total derivative liabilities		0	0
Level 2
Assets
Debt securities available for sale		32,574	29,240
Loans held for sale at fair value		1,065	825
Total derivative assets		1,524	1,473
Equity securities, at fair value		0	0
Short-term investments		32	13
Total assets		35,195	31,551
Liabilities
Total derivative liabilities		1,255	1,708
Short-term borrowed funds		12	0
Other liabilities		157	101
Total liabilities		1,424	1,809
Level 2 | Mortgage-backed securities
Assets
Debt securities available for sale		32,484	29,055
Level 2 | Collateralized loan obligations
Assets
Debt securities available for sale		89	184
Level 2 | State and political subdivisions
Assets
Debt securities available for sale		1	1
Level 2 | U.S. Treasury and other
Assets
Debt securities available for sale		0	0
Level 2 | Residential loans held for sale
Assets
Loans held for sale at fair value		895	633
Level 2 | Commercial loans held for sale
Assets
Loans held for sale at fair value		170	192
Level 2 | Mortgage Servicing Rights
Assets
Mortgage servicing rights		0	0
Level 2 | Interest rate contracts
Assets
Total derivative assets		553	562
Liabilities
Total derivative liabilities		471	910
Level 2 | Foreign exchange contracts
Assets
Total derivative assets		510	472
Liabilities
Total derivative liabilities		373	411
Level 2 | Commodities contracts
Assets
Total derivative assets		458	429
Liabilities
Total derivative liabilities		405	379
Level 2 | TBA contracts
Assets
Total derivative assets		2	10
Liabilities
Total derivative liabilities		6	8
Level 2 | Other contracts
Assets
Total derivative assets		1	0
Liabilities
Total derivative liabilities		0	0
Level 3
Assets
Debt securities available for sale		0	0
Loans held for sale at fair value		0	0
Total derivative assets		8	3
Equity securities, at fair value		0	0
Short-term investments		0	0
Total assets		1,463	1,494
Liabilities
Total derivative liabilities		3	2
Short-term borrowed funds		0	0
Other liabilities		0	0
Total liabilities		3	2
Level 3 | Mortgage-backed securities
Assets
Debt securities available for sale		0	0
Level 3 | Collateralized loan obligations
Assets
Debt securities available for sale		0	0
Level 3 | State and political subdivisions
Assets
Debt securities available for sale		0	0
Level 3 | U.S. Treasury and other
Assets
Debt securities available for sale		0	0
Level 3 | Residential loans held for sale
Assets
Loans held for sale at fair value		0	0
Level 3 | Commercial loans held for sale
Assets
Loans held for sale at fair value		0	0
Level 3 | Mortgage Servicing Rights
Assets
Mortgage servicing rights		1,455	1,491
Level 3 | Interest rate contracts
Assets
Total derivative assets		0	0
Liabilities
Total derivative liabilities		0	0
Level 3 | Foreign exchange contracts
Assets
Total derivative assets		0	0
Liabilities
Total derivative liabilities		0	0
Level 3 | Commodities contracts
Assets
Total derivative assets		0	0
Liabilities
Total derivative liabilities		0	0
Level 3 | TBA contracts
Assets
Total derivative assets		0	0
Liabilities
Total derivative liabilities		0	0
Level 3 | Other contracts
Assets
Total derivative assets		8	3
Liabilities
Total derivative liabilities		3	2
Investments Measured at Net Asset Value
Liabilities
Equity securities, at fair value		66	58
Unfunded capital commitments		$ 14	$ 24

[1] Includes only collateral pledged by the Company where counterparties have the right to sell or pledge the collateral.