FAIR VALUE MEASUREMENTS - Schedule of Fair Value Measurements (Details) - USD ($) $ in Millions		Jun. 30, 2024	Dec. 31, 2023
Assets
Fair Value	[1]	$ 31,938	$ 29,777
Loans held for sale, at fair value		591	676
Mortgage servicing rights		1,568	1,552
Derivative assets		1,350	1,593
Equity securities, at fair value		135	115
Short-term investments		61
Total assets		35,643	33,713
Liabilities
Total derivative liabilities		2,059	2,183
Short-term borrowed funds		2
Total liabilities		2,061	2,183
Equity securities excluded from investments		192	173
Interest rate contracts
Assets
Derivative assets		479	464
Liabilities
Total derivative liabilities		1,298	1,149
Foreign exchange contracts
Assets
Derivative assets		345	434
Liabilities
Total derivative liabilities		285	378
Commodities contracts
Assets
Derivative assets		516	685
Liabilities
Total derivative liabilities		467	640
TBA contracts
Assets
Derivative assets		3	3
Liabilities
Total derivative liabilities		8	16
Other contracts
Assets
Derivative assets		7	7
Liabilities
Total derivative liabilities		1	0
Level 1
Assets
Fair Value		5,012	4,380
Loans held for sale, at fair value		0	0
Derivative assets		0	0
Equity securities, at fair value		135	115
Short-term investments		30
Total assets		5,177	4,495
Liabilities
Total derivative liabilities		0	0
Short-term borrowed funds		0
Total liabilities		0	0
Level 1 | Interest rate contracts
Assets
Derivative assets		0	0
Liabilities
Total derivative liabilities		0	0
Level 1 | Foreign exchange contracts
Assets
Derivative assets		0	0
Liabilities
Total derivative liabilities		0	0
Level 1 | Commodities contracts
Assets
Derivative assets		0	0
Liabilities
Total derivative liabilities		0	0
Level 1 | TBA contracts
Assets
Derivative assets		0	0
Liabilities
Total derivative liabilities		0	0
Level 1 | Other contracts
Assets
Derivative assets		0	0
Liabilities
Total derivative liabilities		0	0
Level 2
Assets
Fair Value		26,926	25,397
Loans held for sale, at fair value		591	676
Derivative assets		1,343	1,586
Equity securities, at fair value		0	0
Short-term investments		31
Total assets		28,891	27,659
Liabilities
Total derivative liabilities		2,058	2,183
Short-term borrowed funds		2
Total liabilities		2,060	2,183
Level 2 | Interest rate contracts
Assets
Derivative assets		479	464
Liabilities
Total derivative liabilities		1,298	1,149
Level 2 | Foreign exchange contracts
Assets
Derivative assets		345	434
Liabilities
Total derivative liabilities		285	378
Level 2 | Commodities contracts
Assets
Derivative assets		516	685
Liabilities
Total derivative liabilities		467	640
Level 2 | TBA contracts
Assets
Derivative assets		3	3
Liabilities
Total derivative liabilities		8	16
Level 2 | Other contracts
Assets
Derivative assets		0	0
Liabilities
Total derivative liabilities		0	0
Level 3
Assets
Fair Value		0	0
Loans held for sale, at fair value		0	0
Derivative assets		7	7
Equity securities, at fair value		0	0
Short-term investments		0
Total assets		1,575	1,559
Liabilities
Total derivative liabilities		1	0
Short-term borrowed funds		0
Total liabilities		1	0
Level 3 | Interest rate contracts
Assets
Derivative assets		0	0
Liabilities
Total derivative liabilities		0	0
Level 3 | Foreign exchange contracts
Assets
Derivative assets		0	0
Liabilities
Total derivative liabilities		0	0
Level 3 | Commodities contracts
Assets
Derivative assets		0	0
Liabilities
Total derivative liabilities		0	0
Level 3 | TBA contracts
Assets
Derivative assets		0	0
Liabilities
Total derivative liabilities		0	0
Level 3 | Other contracts
Assets
Derivative assets		7	7
Liabilities
Total derivative liabilities		1	0
Fair Value Measured at Net Asset Value Per Share
Liabilities
Equity securities excluded from investments		57	58
Unfunded capital commitments		24	28
Mortgage-backed securities
Assets
Fair Value		26,631	24,732
Mortgage-backed securities | Level 1
Assets
Fair Value		0	0
Mortgage-backed securities | Level 2
Assets
Fair Value		26,631	24,732
Mortgage-backed securities | Level 3
Assets
Fair Value		0	0
Collateralized loan obligations
Assets
Fair Value		294	664
Collateralized loan obligations | Level 1
Assets
Fair Value		0	0
Collateralized loan obligations | Level 2
Assets
Fair Value		294	664
Collateralized loan obligations | Level 3
Assets
Fair Value		0	0
State and political subdivisions
Assets
Fair Value		1	1
State and political subdivisions | Level 1
Assets
Fair Value		0	0
State and political subdivisions | Level 2
Assets
Fair Value		1	1
State and political subdivisions | Level 3
Assets
Fair Value		0	0
U.S. Treasury and other
Assets
Fair Value		5,012	4,380
U.S. Treasury and other | Level 1
Assets
Fair Value		5,012	4,380
U.S. Treasury and other | Level 2
Assets
Fair Value		0	0
U.S. Treasury and other | Level 3
Assets
Fair Value		0	0
Residential loans held for sale
Assets
Loans held for sale, at fair value		519	614
Residential loans held for sale | Level 1
Assets
Loans held for sale, at fair value		0	0
Residential loans held for sale | Level 2
Assets
Loans held for sale, at fair value		519	614
Residential loans held for sale | Level 3
Assets
Loans held for sale, at fair value		0	0
Commercial loans held for sale
Assets
Loans held for sale, at fair value		72	62
Commercial loans held for sale | Level 1
Assets
Loans held for sale, at fair value		0	0
Commercial loans held for sale | Level 2
Assets
Loans held for sale, at fair value		72	62
Commercial loans held for sale | Level 3
Assets
Loans held for sale, at fair value		0	0
Mortgage servicing rights
Assets
Mortgage servicing rights		1,568	1,552
Mortgage servicing rights | Level 1
Assets
Mortgage servicing rights		0	0
Mortgage servicing rights | Level 2
Assets
Mortgage servicing rights		0	0
Mortgage servicing rights | Level 3
Assets
Mortgage servicing rights		$ 1,568	$ 1,552

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