FAIR VALUE MEASUREMENT - Valuation Techniques and Inputs for Level 3 Fair Value Measurements (Details)	Sep. 30, 2025 USD ($) year decimal	Dec. 31, 2024 USD ($) year decimal
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Debt securities available-for-sale (AFS)	$ 246,227,000,000	$ 226,876,000,000
Marketable equity securities	684,000,000	578,000,000
Derivative assets	54,497,000,000	60,599,000,000
Mortgage-backed securities
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Debt securities available-for-sale (AFS)	36,648,000,000	29,931,000,000
Model-based | Level 3
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Securities borrowed and purchased under agreements to resell		128,000,000
State and municipal, foreign government, corporate and other debt securities		489,000,000
Marketable equity securities		22,000,000
Non-marketable equities	71,000,000	50,000,000
Loans and leases		177,000,000
Mortgage servicing rights		84,000,000
Interest-bearing deposits		39,000,000
Securities loaned and sold under agreement to repurchase	1,082,000,000
Short-term borrowings and long-term debt	22,686,000,000
Securities loaned or sold under agreements to repurchase		390,000,000
Model-based | Level 3 | Interest rate contracts (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets	4,036,000,000	3,574,000,000
Model-based | Level 3 | Foreign exchange contracts (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets	1,279,000,000	1,247,000,000
Model-based | Level 3 | Equity contracts (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets	4,995,000,000	4,345,000,000
Model-based | Level 3 | Commodity and other contracts (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets	1,769,000,000	1,716,000,000
Model-based | Level 3 | Credit derivatives (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets	1,140,000,000	869,000,000
Model-based | Level 3 | State And Municipal, Foreign Government, Corporate And Other Debt Securities
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Debt securities available-for-sale (AFS)	687,000,000
Yield analysis | Level 3
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Mortgage-backed securities		230,000,000
Asset-backed securities		47,000,000
Securities loaned or sold under agreements to repurchase and other trading liabilities		20,883,000,000
Yield analysis | Level 3 | Mortgage-backed securities
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Debt securities available-for-sale (AFS)	244,000,000
Price-based | Level 3
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Mortgage-backed securities		214,000,000
State and municipal, foreign government, corporate and other debt securities		560,000,000
Marketable equity securities		131,000,000
Asset-backed securities		132,000,000
Non-marketable equities	96,000,000	81,000,000
Loans and leases		82,000,000
Securities loaned or sold under agreements to repurchase and other trading liabilities		27,000,000
Other financial assets and liabilities (gross)		14,000,000
Price-based | Level 3 | Credit derivatives (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets	977,000,000
Price-based | Level 3 | Mortgage-backed securities
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Debt securities available-for-sale (AFS)	337,000,000
Price-based | Level 3 | State And Municipal, Foreign Government, Corporate And Other Debt Securities
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Debt securities available-for-sale (AFS)	722,000,000
Comparable analysis | Level 3
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Non-marketable equities	277,000,000	222,000,000
Cash flow | Level 3
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
State and municipal, foreign government, corporate and other debt securities		140,000,000
Non-marketable equities		50,000,000
Mortgage servicing rights	$ 659,000,000	$ 671,000,000
Minimum | Model-based | Level 3 | Yield
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
State and municipal, foreign government, corporate and other debt securities		0.0420
Mortgage servicing rights		0.0030
Minimum | Model-based | Level 3 | Yield | Interest rate contracts (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets		0.0169
Minimum | Model-based | Level 3 | Yield | Foreign exchange contracts (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets		0.0169
Minimum | Model-based | Level 3 | Credit spread
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
State and municipal, foreign government, corporate and other debt securities		0.0035
Securities borrowed and purchased under agreements to resell		0.10%
Minimum | Model-based | Level 3 | Credit spread | Credit derivatives (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets	0.000517	0.000500
Minimum | Model-based | Level 3 | Credit spread | State And Municipal, Foreign Government, Corporate And Other Debt Securities
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Debt securities, measurement input	0.016700
Minimum | Model-based | Level 3 | Equity volatility
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans and leases		0.3542
Short-term borrowings and long-term debt	0.0603
Minimum | Model-based | Level 3 | Equity volatility | Interest rate contracts (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets	0.0359
Minimum | Model-based | Level 3 | Equity volatility | Foreign exchange contracts (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets	0.0300
Minimum | Model-based | Level 3 | Equity volatility | Equity contracts (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets	0.0300	0
Minimum | Model-based | Level 3 | IR normal volatility
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Securities loaned and sold under agreement to repurchase	0.0050
Short-term borrowings and long-term debt	0.0005	(0.3400)
Securities loaned and sold under agreements to repurchase		0.0067
Minimum | Model-based | Level 3 | IR normal volatility | Interest rate contracts (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets	0.0005	0.0016
Minimum | Model-based | Level 3 | IR normal volatility | Foreign exchange contracts (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets	0.0050	0.0067
Minimum | Model-based | Level 3 | Recovery rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets	0.0625
Minimum | Model-based | Level 3 | Recovery rate | Credit derivatives (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets	0.0050	0.2000
Minimum | Model-based | Level 3 | Interest rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Securities loaned and sold under agreement to repurchase	0.0211
Securities loaned and sold under agreements to repurchase		0.0425
Securities borrowed and purchased under agreements to resell		3.81%
Minimum | Model-based | Level 3 | Interest rate | Interest rate contracts (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets		0.7178
Minimum | Model-based | Level 3 | WAL
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Marketable equity securities | year		2.40
Derivative assets | year	2.65
Minimum | Model-based | Level 3 | Equity forward
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Short-term borrowings and long-term debt	0.6915
Minimum | Model-based | Level 3 | Equity forward | Equity contracts (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets	0.6915	0.7178
Minimum | Model-based | Level 3 | IR basis | Foreign exchange contracts (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets	(0.0117)	(0.0750)
Minimum | Model-based | Level 3 | Equity-Equity correlation | Equity contracts (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets	(0.3622)	(0.3622)
Minimum | Model-based | Level 3 | FX volatility
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Securities loaned or sold under agreements to repurchase and other trading liabilities, measurement		0
Minimum | Model-based | Level 3 | FX volatility | Foreign exchange contracts (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets	0.0271	0.0333
Minimum | Model-based | Level 3 | Forward price
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans and leases		0.0184
Interest-bearing deposits		1.0000
Minimum | Model-based | Level 3 | Forward price | Commodity and other contracts (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets	0.0016	0.0184
Minimum | Model-based | Level 3 | Equity-FX correlation | Equity contracts (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets	(0.7500)	(0.9333)
Short-term borrowings and long-term debt	(0.7500)
Minimum | Model-based | Level 3 | Commodity volatility | Commodity and other contracts (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets	0.0206	0.0714
Minimum | Model-based | Level 3 | Credit spread volatility | Credit derivatives (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets		0.2985
Minimum | Model-based | Level 3 | Credit spread volatility | Credit derivatives (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets	0.3294
Minimum | Model-based | Level 3 | Measurement Input, Recovery [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Marketable equity securities		8,628,000,000
Minimum | Model-based | Level 3 | Equity-IR correlation
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Short-term borrowings and long-term debt	(0.4200)
Minimum | Yield analysis | Level 3 | Yield
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Mortgage-backed securities		0.0524
Asset-backed securities		0.0585
Securities loaned or sold under agreements to repurchase and other trading liabilities, measurement		0.0004
Minimum | Yield analysis | Level 3 | Yield | Mortgage-backed securities
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Debt securities, measurement input	0.0437
Minimum | Price-based | Level 3 | Credit derivatives (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets		$ 468,000,000
Minimum | Price-based | Level 3 | Price
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Mortgage-backed securities		0.01
State and municipal, foreign government, corporate and other debt securities		0
Marketable equity securities		0
Asset-backed securities		3.46
Non-marketable equities	2.90	0.54
Loans and leases		73.88
Securities loaned or sold under agreements to repurchase and other trading liabilities, measurement		0
Other financial assets and liabilities (gross)		$ 91.12
Minimum | Price-based | Level 3 | Price | Credit derivatives (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets	65.10	43.71
Minimum | Price-based | Level 3 | Price | Mortgage-backed securities
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Debt securities, measurement input	1.07
Minimum | Price-based | Level 3 | Price | State And Municipal, Foreign Government, Corporate And Other Debt Securities
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Debt securities, measurement input	0
Minimum | Price-based | Level 3 | Discount rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Non-marketable equities	0.1260
Minimum | Price-based | Level 3 | Upfront points | Credit derivatives (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets	0.0413	(0.0625)
Minimum | Comparable analysis | Level 3 | Illiquidity discount
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Non-marketable equities	0.0770	0.0740
Minimum | Comparable analysis | Level 3 | Revenue multiple
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Non-marketable equities | decimal	8.61	4.50
Minimum | Comparable analysis | Level 3 | EBITDA multiples
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Non-marketable equities | decimal	14.20	16.20
Minimum | Cash flow | Level 3 | Yield
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Mortgage servicing rights	(0.0010)
Minimum | Cash flow | Level 3 | WAL
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
State and municipal, foreign government, corporate and other debt securities | year		3.59
Mortgage servicing rights | year	3.33	3.59
Minimum | Cash flow | Level 3 | Discount rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Non-marketable equities		0.0975
Maximum | Model-based | Level 3 | Yield
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
State and municipal, foreign government, corporate and other debt securities		0.1060
Mortgage servicing rights		0.1200
Maximum | Model-based | Level 3 | Yield | Interest rate contracts (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets		0.4632
Maximum | Model-based | Level 3 | Yield | Foreign exchange contracts (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets		0.4632
Maximum | Model-based | Level 3 | Credit spread
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
State and municipal, foreign government, corporate and other debt securities		0.0550
Securities borrowed and purchased under agreements to resell		0.10%
Maximum | Model-based | Level 3 | Credit spread | Credit derivatives (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets	0.118000	0.074727
Maximum | Model-based | Level 3 | Credit spread | State And Municipal, Foreign Government, Corporate And Other Debt Securities
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Debt securities, measurement input	0.050830
Maximum | Model-based | Level 3 | Equity volatility
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans and leases		0.4194
Short-term borrowings and long-term debt	0.9630
Maximum | Model-based | Level 3 | Equity volatility | Interest rate contracts (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets	0.4292
Maximum | Model-based | Level 3 | Equity volatility | Foreign exchange contracts (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets	0.1580
Maximum | Model-based | Level 3 | Equity volatility | Equity contracts (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets	0.9655	1.4541
Maximum | Model-based | Level 3 | IR normal volatility
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Securities loaned and sold under agreement to repurchase	0.0089
Short-term borrowings and long-term debt	0.0299	0.6000
Securities loaned and sold under agreements to repurchase		0.0113
Maximum | Model-based | Level 3 | IR normal volatility | Interest rate contracts (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets	0.0299	0.2000
Maximum | Model-based | Level 3 | IR normal volatility | Foreign exchange contracts (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets	0.0087	0.0113
Maximum | Model-based | Level 3 | Recovery rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets	0.0625
Maximum | Model-based | Level 3 | Recovery rate | Credit derivatives (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets	0.4000	0.7200
Maximum | Model-based | Level 3 | Interest rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Securities loaned and sold under agreement to repurchase	0.0540
Securities loaned and sold under agreements to repurchase		0.0485
Securities borrowed and purchased under agreements to resell		3.81%
Maximum | Model-based | Level 3 | Interest rate | Interest rate contracts (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets		3.3429
Maximum | Model-based | Level 3 | WAL
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Marketable equity securities | year		2.40
Derivative assets | year	2.65
Maximum | Model-based | Level 3 | Equity forward
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Short-term borrowings and long-term debt	3.4785
Maximum | Model-based | Level 3 | Equity forward | Equity contracts (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets	3.4785	3.3429
Maximum | Model-based | Level 3 | IR basis | Foreign exchange contracts (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets	0.0278	0.6475
Maximum | Model-based | Level 3 | Equity-Equity correlation | Equity contracts (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets	0.9891	0.9900
Maximum | Model-based | Level 3 | FX volatility
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Securities loaned or sold under agreements to repurchase and other trading liabilities, measurement		1.4541
Maximum | Model-based | Level 3 | FX volatility | Foreign exchange contracts (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets	0.2829	0.2764
Maximum | Model-based | Level 3 | Forward price
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans and leases		2.4441
Interest-bearing deposits		1.0000
Maximum | Model-based | Level 3 | Forward price | Commodity and other contracts (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets	3.3480	2.4441
Maximum | Model-based | Level 3 | Equity-FX correlation | Equity contracts (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets	0.7000	0.7000
Short-term borrowings and long-term debt	0.7000
Maximum | Model-based | Level 3 | Commodity volatility | Commodity and other contracts (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets	2.4289	2.8561
Maximum | Model-based | Level 3 | Credit spread volatility | Credit derivatives (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets		0.8144
Maximum | Model-based | Level 3 | Credit spread volatility | Credit derivatives (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets	1.1279
Maximum | Model-based | Level 3 | Measurement Input, Recovery [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Marketable equity securities		8,628,000,000
Maximum | Model-based | Level 3 | Equity-IR correlation
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Short-term borrowings and long-term debt	0.5000
Maximum | Yield analysis | Level 3 | Yield
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Mortgage-backed securities		0.1843
Asset-backed securities		0.1276
Securities loaned or sold under agreements to repurchase and other trading liabilities, measurement		0.2000
Maximum | Yield analysis | Level 3 | Yield | Mortgage-backed securities
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Debt securities, measurement input	0.2241
Maximum | Price-based | Level 3 | Price
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Mortgage-backed securities		99.81
State and municipal, foreign government, corporate and other debt securities		173.20
Marketable equity securities		14,382.07
Asset-backed securities		132.54
Non-marketable equities	353.72	2,960.96
Loans and leases		99.25
Securities loaned or sold under agreements to repurchase and other trading liabilities, measurement		14,382.07
Other financial assets and liabilities (gross)		$ 104.49
Maximum | Price-based | Level 3 | Price | Credit derivatives (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets	112.55	103.53
Maximum | Price-based | Level 3 | Price | Mortgage-backed securities
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Debt securities, measurement input	108.15
Maximum | Price-based | Level 3 | Price | State And Municipal, Foreign Government, Corporate And Other Debt Securities
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Debt securities, measurement input	201.78
Maximum | Price-based | Level 3 | Discount rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Non-marketable equities	0.1750
Maximum | Price-based | Level 3 | Upfront points | Credit derivatives (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets	1.0628	1.1052
Maximum | Comparable analysis | Level 3 | Illiquidity discount
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Non-marketable equities	0.3300	0.3300
Maximum | Comparable analysis | Level 3 | Revenue multiple
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Non-marketable equities | decimal	30.71	16.31
Maximum | Comparable analysis | Level 3 | EBITDA multiples
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Non-marketable equities | decimal	17.80	16.20
Maximum | Cash flow | Level 3 | Yield
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Mortgage servicing rights	0.1200
Maximum | Cash flow | Level 3 | WAL
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
State and municipal, foreign government, corporate and other debt securities | year		8.82
Mortgage servicing rights | year	8.29	8.82
Maximum | Cash flow | Level 3 | Discount rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Non-marketable equities		0.1750
Weighted Average | Model-based | Level 3 | Yield
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
State and municipal, foreign government, corporate and other debt securities		0.0988
Mortgage servicing rights		0.0682
Weighted Average | Model-based | Level 3 | Yield | Interest rate contracts (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets		0.0564
Weighted Average | Model-based | Level 3 | Yield | Foreign exchange contracts (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets		0.0926
Weighted Average | Model-based | Level 3 | Credit spread
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
State and municipal, foreign government, corporate and other debt securities		0.0277
Securities borrowed and purchased under agreements to resell		0.10%
Weighted Average | Model-based | Level 3 | Credit spread | Credit derivatives (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets	0.013275	0.010050
Weighted Average | Model-based | Level 3 | Credit spread | State And Municipal, Foreign Government, Corporate And Other Debt Securities
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Debt securities, measurement input	0.036691
Weighted Average | Model-based | Level 3 | Equity volatility
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans and leases		0.3721
Short-term borrowings and long-term debt	0.1911
Weighted Average | Model-based | Level 3 | Equity volatility | Interest rate contracts (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets	0.1330
Weighted Average | Model-based | Level 3 | Equity volatility | Foreign exchange contracts (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets	0.0687
Weighted Average | Model-based | Level 3 | Equity volatility | Equity contracts (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets	0.1864	0.3289
Weighted Average | Model-based | Level 3 | IR normal volatility
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Securities loaned and sold under agreement to repurchase	0.0059
Short-term borrowings and long-term debt	0.0076	0.2729
Securities loaned and sold under agreements to repurchase		0.0093
Weighted Average | Model-based | Level 3 | IR normal volatility | Interest rate contracts (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets	0.0064	0.0218
Weighted Average | Model-based | Level 3 | IR normal volatility | Foreign exchange contracts (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets	0.0077	0.0093
Weighted Average | Model-based | Level 3 | Recovery rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets	0.0625
Weighted Average | Model-based | Level 3 | Recovery rate | Credit derivatives (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets	0.3115	0.4154
Weighted Average | Model-based | Level 3 | Interest rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Securities loaned and sold under agreement to repurchase	0.0371
Securities loaned and sold under agreements to repurchase		0.0428
Securities borrowed and purchased under agreements to resell		3.81%
Weighted Average | Model-based | Level 3 | Interest rate | Interest rate contracts (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets		1.0648
Weighted Average | Model-based | Level 3 | WAL
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Marketable equity securities | year		2.40
Derivative assets | year	2.65
Weighted Average | Model-based | Level 3 | Equity forward
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Short-term borrowings and long-term debt	1.1448
Weighted Average | Model-based | Level 3 | Equity forward | Equity contracts (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets	1.1199	1.0590
Weighted Average | Model-based | Level 3 | IR basis | Foreign exchange contracts (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets	(0.0007)	0.0501
Weighted Average | Model-based | Level 3 | Equity-Equity correlation | Equity contracts (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets	0.6816	0.7243
Weighted Average | Model-based | Level 3 | FX volatility
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Securities loaned or sold under agreements to repurchase and other trading liabilities, measurement		0.1981
Weighted Average | Model-based | Level 3 | FX volatility | Foreign exchange contracts (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets	0.0769	0.1255
Weighted Average | Model-based | Level 3 | Forward price
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans and leases		1.0292
Interest-bearing deposits		1.0000
Weighted Average | Model-based | Level 3 | Forward price | Commodity and other contracts (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets	1.0152	1.1584
Weighted Average | Model-based | Level 3 | Equity-FX correlation | Equity contracts (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets	(0.1514)	(0.1452)
Short-term borrowings and long-term debt	(0.2106)
Weighted Average | Model-based | Level 3 | Commodity volatility | Commodity and other contracts (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets	0.4440	0.3586
Weighted Average | Model-based | Level 3 | Credit spread volatility | Credit derivatives (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets		0.6758
Weighted Average | Model-based | Level 3 | Credit spread volatility | Credit derivatives (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets	0.9414
Weighted Average | Model-based | Level 3 | Measurement Input, Recovery [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Marketable equity securities		8,628,000,000
Weighted Average | Model-based | Level 3 | Equity-IR correlation
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Short-term borrowings and long-term debt	0.2632
Weighted Average | Yield analysis | Level 3 | Yield
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Mortgage-backed securities		0.0925
Asset-backed securities		0.0807
Securities loaned or sold under agreements to repurchase and other trading liabilities, measurement		0.0154
Weighted Average | Yield analysis | Level 3 | Yield | Mortgage-backed securities
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Debt securities, measurement input	0.0755
Weighted Average | Price-based | Level 3 | Price
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Mortgage-backed securities		35.24
State and municipal, foreign government, corporate and other debt securities		98.52
Marketable equity securities		442.64
Asset-backed securities		74.86
Non-marketable equities	125.66	432.84
Loans and leases		85.09
Securities loaned or sold under agreements to repurchase and other trading liabilities, measurement		91.47
Other financial assets and liabilities (gross)		$ 100.04
Weighted Average | Price-based | Level 3 | Price | Credit derivatives (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets	91.95	85.76
Weighted Average | Price-based | Level 3 | Price | Mortgage-backed securities
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Debt securities, measurement input	34.07
Weighted Average | Price-based | Level 3 | Price | State And Municipal, Foreign Government, Corporate And Other Debt Securities
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Debt securities, measurement input	108.92
Weighted Average | Price-based | Level 3 | Discount rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Non-marketable equities	0.1592
Weighted Average | Price-based | Level 3 | Upfront points | Credit derivatives (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets	0.6079	0.4393
Weighted Average | Comparable analysis | Level 3 | Illiquidity discount
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Non-marketable equities	0.1660	0.1647
Weighted Average | Comparable analysis | Level 3 | Revenue multiple
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Non-marketable equities | decimal	14.10	11.97
Weighted Average | Comparable analysis | Level 3 | EBITDA multiples
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Non-marketable equities | decimal	16.00	16.20
Weighted Average | Cash flow | Level 3 | Yield
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Mortgage servicing rights	0.0654
Weighted Average | Cash flow | Level 3 | WAL
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
State and municipal, foreign government, corporate and other debt securities | year		7.57
Mortgage servicing rights | year	7.07	7.57
Weighted Average | Cash flow | Level 3 | Discount rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Non-marketable equities		0.1328