Fair Value Measurements - Quantitative Information about Recurring Fair Value Measurement of Assets and Liabilities Classified as Level 3 (Detail) $ in Millions		Sep. 30, 2022 USD ($) $ / shares	Dec. 31, 2021 USD ($)
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Securities available-for-sale	[1]	$ 28,082	$ 35,298
Mortgage servicing rights		23	16
Domestic deposits		(378)	(535)
Long-term debt	[1]	(15,696)	(17,236)
Structured notes
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Long-term debt		(2,316)	(1,853)
Asset-backed securities
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Securities available-for-sale		107	120
Interest rate contracts
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Derivative assets (liability		(5)	0
Foreign exchange contracts
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Derivative assets (liability			(2)
Equity contracts
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Derivative assets (liability		(346)	46
Credit contracts
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Derivative assets (liability			(2)
Other Contracts
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Derivative assets (liability		$ (29)	$ (33)
Probability to fund for rate lock commitments | Interest rate contracts | Recurring | Minimum | Market comparable adjusted for probability to fund and, where applicable, option pricing model
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Derivatives		0.58	0.36
Probability to fund for rate lock commitments | Interest rate contracts | Recurring | Maximum | Market comparable adjusted for probability to fund and, where applicable, option pricing model
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Derivatives		0.99	0.99
Probability to fund for rate lock commitments | Interest rate contracts | Recurring | Weighted Average | Market comparable adjusted for probability to fund and, where applicable, option pricing model
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Derivatives		0.87	0.83
Interest rate yield curve | Interest rate contracts | Recurring | Market comparable adjusted for probability to fund and, where applicable, option pricing model
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Derivatives		0.09	0.08
Implied volatility of currency pairs | Recurring | Minimum | Option adjusted discounted cash flows | Structured notes
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Long-term debt			0
Implied volatility of currency pairs | Recurring | Maximum | Option adjusted discounted cash flows | Structured notes
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Long-term debt			0.09
Implied volatility of currency pairs | Recurring | Weighted Average | Option adjusted discounted cash flows | Structured notes
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Long-term debt			0.06
Implied volatility of currency pairs | Foreign exchange contracts | Recurring | Minimum | Option pricing model
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Derivatives			0
Implied volatility of currency pairs | Foreign exchange contracts | Recurring | Maximum | Option pricing model
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Derivatives			0.09
Implied volatility of currency pairs | Foreign exchange contracts | Recurring | Weighted Average | Option pricing model
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Derivatives			0.06
Cross-currency basis | Foreign exchange contracts | Recurring | Option pricing model
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Derivatives			(0.0086)
Equity / Equity Index volatility | Recurring | Minimum | Option adjusted discounted cash flows
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Domestic deposits		0.08	0.08
Equity / Equity Index volatility | Recurring | Minimum | Option adjusted discounted cash flows | Structured notes
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Long-term debt		0.08	0.08
Equity / Equity Index volatility | Recurring | Maximum | Option adjusted discounted cash flows
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Domestic deposits		0.27	0.21
Equity / Equity Index volatility | Recurring | Maximum | Option adjusted discounted cash flows | Structured notes
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Long-term debt		0.55	0.71
Equity / Equity Index volatility | Recurring | Weighted Average | Option adjusted discounted cash flows
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Domestic deposits		0.17	0.15
Equity / Equity Index volatility | Recurring | Weighted Average | Option adjusted discounted cash flows | Structured notes
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Long-term debt		0.32	0.31
Equity / Equity Index volatility | Equity contracts | Recurring | Minimum | Option pricing model
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Derivatives		0.08	0.08
Equity / Equity Index volatility | Equity contracts | Recurring | Maximum | Option pricing model
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Derivatives		0.90	0.85
Equity / Equity Index volatility | Equity contracts | Recurring | Weighted Average | Option pricing model
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Derivatives		0.44	0.40
Equity / Equity and Equity / Index correlation | Recurring | Minimum | Option adjusted discounted cash flows
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Domestic deposits		0.49	0.49
Equity / Equity and Equity / Index correlation | Recurring | Minimum | Option adjusted discounted cash flows | Structured notes
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Long-term debt		0.45	0.44
Equity / Equity and Equity / Index correlation | Recurring | Maximum | Option adjusted discounted cash flows
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Domestic deposits		0.89	0.85
Equity / Equity and Equity / Index correlation | Recurring | Maximum | Option adjusted discounted cash flows | Structured notes
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Long-term debt		0.99	0.98
Equity / Equity and Equity / Index correlation | Recurring | Weighted Average | Option adjusted discounted cash flows
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Domestic deposits		0.63	0.62
Equity / Equity and Equity / Index correlation | Recurring | Weighted Average | Option adjusted discounted cash flows | Structured notes
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Long-term debt		0.86	0.82
Equity / Equity and Equity / Index correlation | Equity contracts | Recurring | Minimum | Option pricing model
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Derivatives		0.45	0.44
Equity / Equity and Equity / Index correlation | Equity contracts | Recurring | Maximum | Option pricing model
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Derivatives		0.99	0.98
Equity / Equity and Equity / Index correlation | Equity contracts | Recurring | Weighted Average | Option pricing model
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Derivatives		0.86	0.81
Equity forward price | Equity contracts | Recurring | Minimum | Option pricing model
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Derivatives | $ / shares		72
Equity forward price | Equity contracts | Recurring | Maximum | Option pricing model
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Derivatives | $ / shares		5,039
Equity forward price | Equity contracts | Recurring | Weighted Average | Option pricing model
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Derivatives | $ / shares		1,249
Equity dividend yields and forward price | Equity contracts | Recurring | Minimum | Option pricing model
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Derivatives			(0.04)
Equity dividend yields and forward price | Equity contracts | Recurring | Maximum | Option pricing model
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Derivatives			0.01
Equity dividend yields and forward price | Equity contracts | Recurring | Weighted Average | Option pricing model
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Derivatives			0
Credit default swap spreads | Recurring | Option adjusted discounted cash flows | Structured notes
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Long-term debt		0.1222	0.0798
Credit default swap spreads | Credit contracts | Recurring | Minimum | Option pricing model
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Derivatives			0.0076
Credit default swap spreads | Credit contracts | Recurring | Maximum | Option pricing model
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Derivatives			0.0325
Credit default swap spreads | Credit contracts | Recurring | Weighted Average | Option pricing model
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Derivatives			0.0234
Conversion rate | Other Contracts | Recurring | Discounted cash flows
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Derivatives		1.6	1.6
Expected duration | Other Contracts | Recurring | Discounted cash flows
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Derivatives		1.3	1
Market assumptions related to yields for comparable instruments | Asset-backed securities | Recurring | Minimum | Discounted cash flows
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Available for sale securities		0.02	0.03
Market assumptions related to yields for comparable instruments | Asset-backed securities | Recurring | Maximum | Discounted cash flows
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Available for sale securities		0.03	0.04
Market assumptions related to yields for comparable instruments | Asset-backed securities | Recurring | Weighted Average | Discounted cash flows
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Available for sale securities		0.02	0.03
Constant prepayment rates | Recurring | Minimum | Discounted cash flows
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Mortgage servicing rights		0.06	0.10
Constant prepayment rates | Recurring | Maximum | Discounted cash flows
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Mortgage servicing rights		0.13	0.16
Constant prepayment rates | Recurring | Weighted Average | Discounted cash flows
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Mortgage servicing rights		0.06	0.12
Discount rate | Recurring | Minimum | Discounted cash flows
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Mortgage servicing rights		0.08	0.08
Discount rate | Recurring | Maximum | Discounted cash flows
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Mortgage servicing rights		0.12	0.13
Discount rate | Recurring | Weighted Average | Discounted cash flows
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Mortgage servicing rights		0.09	0.08
Estimated annualized costs to service | Recurring | Minimum | Discounted cash flows
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Mortgage servicing rights		72	72
Estimated annualized costs to service | Recurring | Maximum | Discounted cash flows
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Mortgage servicing rights		76	85
Estimated annualized costs to service | Recurring | Weighted Average | Discounted cash flows
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Mortgage servicing rights		74	75

[1] The following table summarizes assets and liabilities related to our consolidated variable interest entities ("VIEs") at September 30, 2022 and December 31, 2021. Assets and liabilities exclude intercompany balances that eliminate in consolidation. See Note 17, "Variable Interest Entities," for additional information. September 30, 2022December 31, 2021(in millions)AssetsLoans$127 $46 Other assets44 55 Total assets$171 $101 LiabilitiesInterest, taxes and other liabilities$26 $9 Total liabilities$26 $9