FAIR VALUE MEASUREMENT - Valuation Techniques and Inputs for Level 3 Fair Value Measurements (Details)	Sep. 30, 2023 USD ($) year	Dec. 31, 2022 USD ($) year
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Marketable equity securities	$ 738,000,000	$ 895,000,000
Derivative assets	68,554,000,000	75,306,000,000
Model-based | Level 3
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Securities borrowed and purchased under agreements to resell	135,000,000	146,000,000
State and municipal, foreign government, corporate and other debt securities	792,000,000
Marketable equity securities	33,000,000	31,000,000
Non-marketable equities	44,000,000
Loans and leases		1,059,000,000
Mortgage servicing rights		84,000,000
Interest-bearing deposits	85,000,000	15,000,000
Securities loaned and sold under agreement to repurchase	481,000,000
Short-term borrowings and long-term debt	33,941,000,000	36,155,000,000
Securities loaned or sold under agreements to repurchase		970,000,000
Securities loaned or sold under agreements to repurchase and other trading liabilities		6,000,000
Model-based | Level 3 | Interest rate contracts (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets	7,135,000,000	7,108,000,000
Model-based | Level 3 | Foreign exchange contracts (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets	2,201,000,000	1,437,000,000
Model-based | Level 3 | Equity contracts (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets	3,463,000,000	4,430,000,000
Model-based | Level 3 | Commodity and other contracts (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets	2,498,000,000	2,724,000,000
Model-based | Level 3 | Credit derivatives (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets	1,170,000,000	1,520,000,000
Yield analysis | Level 3
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Mortgage-backed securities	614,000,000	732,000,000
Asset-backed securities	77,000,000	308,000,000
Price-based | Level 3
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Mortgage-backed securities	338,000,000	228,000,000
State and municipal, foreign government, corporate and other debt securities	2,107,000,000	2,360,000,000
Marketable equity securities	224,000,000	147,000,000
Asset-backed securities	573,000,000	304,000,000
Non-marketable equities		101,000,000
Nontrading derivatives and other financial assets and liabilities measured on a recurring basis (gross)	105,000,000	57,000,000
Loans and leases	225,000,000	304,000,000
Interest-bearing deposits	70,000,000
Securities sold, not yet purchased and other trading liabilities	85,000,000
Securities loaned or sold under agreements to repurchase and other trading liabilities		47,000,000
Price-based | Level 3 | Credit derivatives (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets	433,000,000	439,000,000
Comparable analysis | Level 3
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Non-marketable equities	296,000,000	287,000,000
Cash flow | Level 3
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Non-marketable equities	53,000,000
Mortgage servicing rights	$ 641,000,000	$ 580,000,000
Minimum | Model-based | Level 3 | Interest rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Securities borrowed and purchased under agreements to resell	4.62%	2.61%
Securities loaned and sold under agreement to repurchase	0.0466
Securities loand and sold under agreements to repurchase		0.0401
Minimum | Model-based | Level 3 | Interest rate | Interest rate contracts (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets	0.0248
Minimum | Model-based | Level 3 | Credit spread
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Securities borrowed and purchased under agreements to resell	0.15%	0.15%
State and municipal, foreign government, corporate and other debt securities	0.0035
Minimum | Model-based | Level 3 | Credit spread | Foreign exchange contracts (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets		0.0116
Minimum | Model-based | Level 3 | Credit spread | Credit derivatives (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets	0.0008	0.000250
Minimum | Model-based | Level 3 | WAL
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Marketable equity securities	2.49	2.24
Mortgage servicing rights | year	3.87	3.92
Minimum | Model-based | Level 3 | WAL | Equity contracts (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets	2.49	2.24
Minimum | Model-based | Level 3 | Recovery
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Marketable equity securities	$ 7,148,000,000
Marketable equity securities		7,148,000,000
Derivative assets	7,148,000,000
Minimum | Model-based | Level 3 | Recovery | Equity contracts (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets		$ 7,148,000,000
Minimum | Model-based | Level 3 | IR normal volatility
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Short-term borrowings and long-term debt	0.0033	0.0033
Minimum | Model-based | Level 3 | IR normal volatility | Interest rate contracts (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets	(0.0925)	0.0033
Minimum | Model-based | Level 3 | IR normal volatility | Foreign exchange contracts (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets	(0.0925)	0.0033
Minimum | Model-based | Level 3 | IR basis | Foreign exchange contracts (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets		(0.0423)
Minimum | Model-based | Level 3 | Equity volatility
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans and leases		0.0005
Minimum | Model-based | Level 3 | Equity volatility | Foreign exchange contracts (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets		0.0005
Minimum | Model-based | Level 3 | Equity volatility | Equity contracts (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets	0.0004	0.0005
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		0.0200
Minimum | Model-based | Level 3 | Equity forward | Equity contracts (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets	0.6456	0.6834
Minimum | Model-based | Level 3 | Equity-FX correlation | Equity contracts (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets	(0.7900)	(0.9500)
Minimum | Model-based | Level 3 | Equity-IR correlation
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets	(0.2500)
Minimum | Model-based | Level 3 | Equity-IR correlation | Equity contracts (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets		(0.1883)
Minimum | Model-based | Level 3 | Commodity correlation | Commodity and other contracts (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets	(0.3967)	(0.3200)
Minimum | Model-based | Level 3 | Commodity volatility | Commodity and other contracts (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets	0.0780	0.1043
Minimum | Model-based | Level 3 | Forward price
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
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	0.1667	0.1427
Minimum | Model-based | Level 3 | Equity-Equity correlation | Equity contracts (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets		(0.0398)
Minimum | Yield analysis | Level 3 | Yield
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Mortgage-backed securities	5.36%	4.41%
Asset-backed securities	6.40%	5.76%
Minimum | Price-based | Level 3 | Price
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Mortgage-backed securities	$ 0.96	$ 1.04
State and municipal, foreign government, corporate and other debt securities	0.85	0.01
Marketable equity securities	0	0
Asset-backed securities	3.97	10.50
Nontrading derivatives and other financial assets and liabilities measured on a recurring basis (gross)	$ 0	$ 80.16
Loans and leases	73.95	0.01
Securities sold, not yet purchased and other trading liabilities	$ 0
Securities loaned or sold under agreements to repurchase and other trading liabilities, measurement		0
Minimum | Price-based | Level 3 | Price | Credit derivatives (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets	14.86
Derivative assets		$ 31.71
Minimum | Price-based | Level 3 | PE ratio
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Non-marketable equities		14.00
Minimum | Price-based | Level 3 | Revenue multiple
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Non-marketable equities		3.60
Minimum | Price-based | Level 3 | Equity forward
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans and leases		0.6834
Minimum | Price-based | Level 3 | Commodity correlation
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans and leases	(0.3967)
Minimum | Price-based | Level 3 | Commodity volatility
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans and leases	0.0780
Minimum | Price-based | Level 3 | Forward price
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans and leases	0.2039	0.1427
Minimum | Price-based | Level 3 | Recovery rate | Credit derivatives (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets	0.2500	0.2500
Minimum | Price-based | Level 3 | Credit correlation | Credit derivatives (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets	0.2500	0.2500
Minimum | Price-based | Level 3 | Upfront points | Credit derivatives (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets	(0.0166)
Minimum | Price-based | Level 3 | Cost of capital
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Non-marketable equities		0.0810
Minimum | Price-based | Level 3 | Credit spread volatility | Credit derivatives (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets		0.3558
Minimum | Price-based | Level 3 | Appraised Value
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Marketable equity securities	$ 4,380,000
Minimum | Comparable analysis | Level 3 | Illiquidity discount
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Non-marketable equities	0.1000	0.0860
Minimum | Cash flow | Level 3 | Yield
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Mortgage servicing rights	0.0050	(0.0040)
Minimum | Cash flow | Level 3 | PE ratio
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Non-marketable equities	12.90
Minimum | Cash flow | Level 3 | Discount to price
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Non-marketable equities	0.0850
Minimum | Cash flow | Level 3 | Revenue multiple
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Non-marketable equities	4.20
Minimum | Model-based | Level 3 | Price
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Interest-bearing deposits	100.00
Minimum | Model-based | Level 3 | Equity forward
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Interest-bearing deposits	1
Minimum | Model-based | Level 3 | Forward price
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Interest-bearing deposits	1
Maximum | Model-based | Level 3 | Interest rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Securities borrowed and purchased under agreements to resell	4.62%	2.61%
Securities loaned and sold under agreement to repurchase	0.0559
Securities loand and sold under agreements to repurchase		0.0497
Maximum | Model-based | Level 3 | Interest rate | Interest rate contracts (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets	0.0367
Maximum | Model-based | Level 3 | Credit spread
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Securities borrowed and purchased under agreements to resell	0.15%	0.15%
State and municipal, foreign government, corporate and other debt securities	0.0550
Maximum | Model-based | Level 3 | Credit spread | Foreign exchange contracts (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets		0.0626
Maximum | Model-based | Level 3 | Credit spread | Credit derivatives (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets	0.0775	0.095510
Maximum | Model-based | Level 3 | WAL
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Marketable equity securities	2.49	2.24
Mortgage servicing rights | year	9.59	9.33
Maximum | Model-based | Level 3 | WAL | Equity contracts (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets	2.49	2.24
Maximum | Model-based | Level 3 | Recovery
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Marketable equity securities	$ 7,148,000,000
Marketable equity securities		7,148,000,000
Derivative assets	7,148,000,000
Maximum | Model-based | Level 3 | Recovery | Equity contracts (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets		$ 7,148,000,000
Maximum | Model-based | Level 3 | IR normal volatility
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Short-term borrowings and long-term debt	0.2000	0.0182
Maximum | Model-based | Level 3 | IR normal volatility | Interest rate contracts (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets	0.4718	0.0182
Maximum | Model-based | Level 3 | IR normal volatility | Foreign exchange contracts (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets	0.4739	0.0147
Maximum | Model-based | Level 3 | IR basis | Foreign exchange contracts (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets		0.0968
Maximum | Model-based | Level 3 | Equity volatility
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans and leases		3.0072
Maximum | Model-based | Level 3 | Equity volatility | Foreign exchange contracts (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets		3.0072
Maximum | Model-based | Level 3 | Equity volatility | Equity contracts (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets	2.9919	3.0072
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		0.4000
Maximum | Model-based | Level 3 | Equity forward | Equity contracts (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets	3.2831	2.7161
Maximum | Model-based | Level 3 | Equity-FX correlation | Equity contracts (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets	0.7000	0.5000
Maximum | Model-based | Level 3 | Equity-IR correlation
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets	0.4400
Maximum | Model-based | Level 3 | Equity-IR correlation | Equity contracts (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets		0.6000
Maximum | Model-based | Level 3 | Commodity correlation | Commodity and other contracts (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets	0.9350	0.9194
Maximum | Model-based | Level 3 | Commodity volatility | Commodity and other contracts (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets	1.0490	1.5150
Maximum | Model-based | Level 3 | Forward price
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Interest-bearing deposits		1.0130
Maximum | Model-based | Level 3 | Forward price | Commodity and other contracts (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets	20	3.8550
Maximum | Model-based | Level 3 | Equity-Equity correlation | Equity contracts (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets		0.9868
Maximum | Yield analysis | Level 3 | Yield
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Mortgage-backed securities	20.06%	20.30%
Asset-backed securities	12.43%	18.58%
Maximum | Price-based | Level 3 | Price
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Mortgage-backed securities	$ 112.94	$ 99.71
State and municipal, foreign government, corporate and other debt securities	102.42	994.68
Marketable equity securities	9,862	9,087.76
Asset-backed securities	139.76	145.00
Nontrading derivatives and other financial assets and liabilities measured on a recurring basis (gross)	$ 9,862.02	$ 105.32
Loans and leases	103.41	100.53
Securities sold, not yet purchased and other trading liabilities	$ 259.90
Securities loaned or sold under agreements to repurchase and other trading liabilities, measurement		9,087.76
Maximum | Price-based | Level 3 | Price | Credit derivatives (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets	100.07
Derivative assets		$ 99.00
Maximum | Price-based | Level 3 | PE ratio
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Non-marketable equities		15.70
Maximum | Price-based | Level 3 | Revenue multiple
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Non-marketable equities		13.90
Maximum | Price-based | Level 3 | Equity forward
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans and leases		2.7161
Maximum | Price-based | Level 3 | Commodity correlation
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans and leases	0.9350
Maximum | Price-based | Level 3 | Commodity volatility
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans and leases	1.0490
Maximum | Price-based | Level 3 | Forward price
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans and leases	5.3483	3.2485
Maximum | Price-based | Level 3 | Recovery rate | Credit derivatives (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets	0.4000	0.7500
Maximum | Price-based | Level 3 | Credit correlation | Credit derivatives (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets	0.9000	0.8000
Maximum | Price-based | Level 3 | Upfront points | Credit derivatives (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets	0.9900
Maximum | Price-based | Level 3 | Cost of capital
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Non-marketable equities		0.1750
Maximum | Price-based | Level 3 | Credit spread volatility | Credit derivatives (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets		0.6479
Maximum | Price-based | Level 3 | Appraised Value
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Marketable equity securities	$ 19,300,000
Maximum | Comparable analysis | Level 3 | Illiquidity discount
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Non-marketable equities	0.2000	0.1700
Maximum | Cash flow | Level 3 | Yield
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Mortgage servicing rights	0.1200	0.1320
Maximum | Cash flow | Level 3 | PE ratio
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Non-marketable equities	15.00
Maximum | Cash flow | Level 3 | Discount to price
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Non-marketable equities	0.3300
Maximum | Cash flow | Level 3 | Revenue multiple
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Non-marketable equities	11.30
Maximum | Model-based | Level 3 | Price
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Interest-bearing deposits	100.00
Maximum | Model-based | Level 3 | Equity forward
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Interest-bearing deposits	1.17
Maximum | Model-based | Level 3 | Forward price
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Interest-bearing deposits	1
Weighted Average | Model-based | Level 3 | Interest rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Securities borrowed and purchased under agreements to resell	4.62%	2.61%
Securities loaned and sold under agreement to repurchase	0.0471
Securities loand and sold under agreements to repurchase		0.0407
Weighted Average | Model-based | Level 3 | Interest rate | Interest rate contracts (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets	0.0278
Weighted Average | Model-based | Level 3 | Credit spread
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Securities borrowed and purchased under agreements to resell	0.15%	0.15%
State and municipal, foreign government, corporate and other debt securities	0.0290
Weighted Average | Model-based | Level 3 | Credit spread | Foreign exchange contracts (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets		0.0594
Weighted Average | Model-based | Level 3 | Credit spread | Credit derivatives (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets	0.0108	0.010127
Weighted Average | Model-based | Level 3 | WAL
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Marketable equity securities	2.49	2.24
Mortgage servicing rights | year	8.06	7.71
Weighted Average | Model-based | Level 3 | WAL | Equity contracts (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets	2.49	2.24
Weighted Average | Model-based | Level 3 | Recovery
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Marketable equity securities	$ 7,148,000,000
Marketable equity securities		7,148,000,000
Derivative assets	7,148,000,000
Weighted Average | Model-based | Level 3 | Recovery | Equity contracts (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets		$ 7,148,000,000
Weighted Average | Model-based | Level 3 | IR normal volatility
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Short-term borrowings and long-term debt	0.0135	0.0089
Weighted Average | Model-based | Level 3 | IR normal volatility | Interest rate contracts (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets	0.0225	0.0096
Weighted Average | Model-based | Level 3 | IR normal volatility | Foreign exchange contracts (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets	0.0328	0.0067
Weighted Average | Model-based | Level 3 | IR basis | Foreign exchange contracts (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets		(0.0003)
Weighted Average | Model-based | Level 3 | Equity volatility
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans and leases		0.4262
Weighted Average | Model-based | Level 3 | Equity volatility | Foreign exchange contracts (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets		0.3391
Weighted Average | Model-based | Level 3 | Equity volatility | Equity contracts (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets	0.3817	0.4147
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		0.1285
Weighted Average | Model-based | Level 3 | Equity forward | Equity contracts (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets	1.1408	1.0350
Weighted Average | Model-based | Level 3 | Equity-FX correlation | Equity contracts (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets	(0.1018)	(0.1633)
Weighted Average | Model-based | Level 3 | Equity-IR correlation
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets	0.2854
Weighted Average | Model-based | Level 3 | Equity-IR correlation | Equity contracts (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets		0.3237
Weighted Average | Model-based | Level 3 | Commodity correlation | Commodity and other contracts (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets	(0.0046)	0.3670
Weighted Average | Model-based | Level 3 | Commodity volatility | Commodity and other contracts (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets	0.2513	0.3355
Weighted Average | Model-based | Level 3 | Forward price
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Interest-bearing deposits		1.0007
Weighted Average | Model-based | Level 3 | Forward price | Commodity and other contracts (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets	1.5387	1.0608
Weighted Average | Model-based | Level 3 | Equity-Equity correlation | Equity contracts (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets		0.8563
Weighted Average | Yield analysis | Level 3 | Yield
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Mortgage-backed securities	9.29%	9.74%
Asset-backed securities	8.13%	9.34%
Weighted Average | Price-based | Level 3 | Price
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Mortgage-backed securities	$ 53.66	$ 51.51
State and municipal, foreign government, corporate and other debt securities	82.51	245.85
Marketable equity securities	91.95	114.29
Asset-backed securities	80.52	74.97
Nontrading derivatives and other financial assets and liabilities measured on a recurring basis (gross)	$ 86.58	$ 92.65
Loans and leases	89.02	84.77
Securities sold, not yet purchased and other trading liabilities	$ 78.73
Securities loaned or sold under agreements to repurchase and other trading liabilities, measurement		41.22
Weighted Average | Price-based | Level 3 | Price | Credit derivatives (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets	82.59
Derivative assets		$ 78.75
Weighted Average | Price-based | Level 3 | PE ratio
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Non-marketable equities		15.16
Weighted Average | Price-based | Level 3 | Revenue multiple
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Non-marketable equities		12.40
Weighted Average | Price-based | Level 3 | Equity forward
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans and leases		1.0349
Weighted Average | Price-based | Level 3 | Commodity correlation
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans and leases	(0.0046)
Weighted Average | Price-based | Level 3 | Commodity volatility
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans and leases	0.2513
Weighted Average | Price-based | Level 3 | Forward price
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans and leases	1.5935	1.0507
Weighted Average | Price-based | Level 3 | Recovery rate | Credit derivatives (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets	0.3913	0.4227
Weighted Average | Price-based | Level 3 | Credit correlation | Credit derivatives (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets	0.4993	0.4238
Weighted Average | Price-based | Level 3 | Upfront points | Credit derivatives (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets	0.4805
Weighted Average | Price-based | Level 3 | Cost of capital
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Non-marketable equities		0.1044
Weighted Average | Price-based | Level 3 | Credit spread volatility | Credit derivatives (gross)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets		0.4047
Weighted Average | Price-based | Level 3 | Appraised Value
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Marketable equity securities	$ 14,400,000
Weighted Average | Comparable analysis | Level 3 | Illiquidity discount
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Non-marketable equities	0.1047	0.1016
Weighted Average | Cash flow | Level 3 | Yield
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Mortgage servicing rights	0.0568	0.0536
Weighted Average | Cash flow | Level 3 | PE ratio
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Non-marketable equities	13.40
Weighted Average | Cash flow | Level 3 | Discount to price
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Non-marketable equities	0.1863
Weighted Average | Cash flow | Level 3 | Revenue multiple
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Non-marketable equities	10.56
Weighted Average | Model-based | Level 3 | Price
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Interest-bearing deposits	100.00
Weighted Average | Model-based | Level 3 | Equity forward
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Interest-bearing deposits	1.03
Weighted Average | Model-based | Level 3 | Forward price
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Interest-bearing deposits	1