Fair Value Measurements - Quantitative Information about Recurring Fair Value Measurement of Assets and Liabilities Classified as Level 3 (Detail) $ in Millions	Jun. 30, 2026 USD ($) $ / shares	Dec. 31, 2025 USD ($)
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Fair Value	$ 32,817	$ 30,030
Long-term debt	(25,305)	(23,026)
Fair Value, Recurring
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Loans held for sale, fair value	795	626
Domestic deposits	(3,752)	(3,570)
Level 3
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Long-term debt	0	0
Level 3 \| Fair Value, Recurring
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Loans held for sale, fair value	264	166
Domestic deposits	(569)	(377)
Structured notes \| Level 3 \| Fair Value, Recurring
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Long-term debt	(2,752)	(2,354)
Asset-backed securities \| Fair Value, Recurring
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Fair Value	287	263
Asset-backed securities \| Level 3 \| Fair Value, Recurring
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Fair Value	71	76
Equity contracts \| Level 3 \| Fair Value, Recurring
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Derivative assets (liability	$ 58	$ 11
Equity / Equity Index volatility \| Minimum \| Option adjusted discounted cash flows \| Fair Value, Recurring
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Domestic deposits	0.05	0.05
Equity / Equity Index volatility \| Minimum \| Option adjusted discounted cash flows \| Structured notes \| Fair Value, Recurring
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Long-term debt	0.11	0.12
Equity / Equity Index volatility \| Maximum \| Option adjusted discounted cash flows \| Fair Value, Recurring
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Domestic deposits	0.66	0.45
Equity / Equity Index volatility \| Maximum \| Option adjusted discounted cash flows \| Structured notes \| Fair Value, Recurring
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Long-term debt	0.86	0.72
Equity / Equity Index volatility \| Weighted Average \| Option adjusted discounted cash flows \| Fair Value, Recurring
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Domestic deposits	0.14	0.12
Equity / Equity Index volatility \| Weighted Average \| Option adjusted discounted cash flows \| Structured notes \| Fair Value, Recurring
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Long-term debt	0.35	0.31
Equity / Equity Index volatility \| Equity contracts \| Minimum \| Option pricing model \| Fair Value, Recurring
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Derivatives	0.05	0.05
Equity / Equity Index volatility \| Equity contracts \| Maximum \| Option pricing model \| Fair Value, Recurring
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Derivatives	1.49	0.90
Equity / Equity Index volatility \| Equity contracts \| Weighted Average \| Option pricing model \| Fair Value, Recurring
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Derivatives	0.61	0.60
Equity / Equity and Equity / Index correlation \| Minimum \| Option adjusted discounted cash flows \| Fair Value, Recurring
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Domestic deposits	0.40	0.42
Equity / Equity and Equity / Index correlation \| Minimum \| Option adjusted discounted cash flows \| Structured notes \| Fair Value, Recurring
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Long-term debt	0.45	0.48
Equity / Equity and Equity / Index correlation \| Maximum \| Option adjusted discounted cash flows \| Fair Value, Recurring
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Domestic deposits	0.95	0.93
Equity / Equity and Equity / Index correlation \| Maximum \| Option adjusted discounted cash flows \| Structured notes \| Fair Value, Recurring
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Long-term debt	0.98	0.98
Equity / Equity and Equity / Index correlation \| Weighted Average \| Option adjusted discounted cash flows \| Fair Value, Recurring
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Domestic deposits	0.67	0.75
Equity / Equity and Equity / Index correlation \| Weighted Average \| Option adjusted discounted cash flows \| Structured notes \| Fair Value, Recurring
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Long-term debt	0.85	0.86
Equity / Equity and Equity / Index correlation \| Equity contracts \| Minimum \| Option pricing model \| Fair Value, Recurring
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Derivatives	0.40	0.42
Equity / Equity and Equity / Index correlation \| Equity contracts \| Maximum \| Option pricing model \| Fair Value, Recurring
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Derivatives	0.98	0.98
Equity / Equity and Equity / Index correlation \| Equity contracts \| Weighted Average \| Option pricing model \| Fair Value, Recurring
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Derivatives	0.83	0.84
Equity forward price \| Equity contracts \| Minimum \| Option pricing model \| Fair Value, Recurring
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Derivatives	0	0
Equity forward price \| Equity contracts \| Maximum \| Option pricing model \| Fair Value, Recurring
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Derivatives	72,824	57,523
Equity forward price \| Equity contracts \| Weighted Average \| Option pricing model \| Fair Value, Recurring
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Derivatives	3,341	2,773
Credit default swap spreads \| Option adjusted discounted cash flows \| Structured notes \| Fair Value, Recurring
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Long-term debt	0.0396	0.0722
Market assumptions related to yields for comparable instruments \| Minimum \| Market comparables and internal assumptions \| Fair Value, Recurring
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Loans Held-for-sale, Measurement Input	0.31	0.28
Market assumptions related to yields for comparable instruments \| Maximum \| Market comparables and internal assumptions \| Fair Value, Recurring
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Loans Held-for-sale, Measurement Input	1	1
Market assumptions related to yields for comparable instruments \| Weighted Average \| Market comparables and internal assumptions \| Fair Value, Recurring
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Loans Held-for-sale, Measurement Input	0.83	0.74
Market assumptions related to yields for comparable instruments \| Asset-backed securities \| Minimum \| Discounted cash flows \| Fair Value, Recurring
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Available for sale securities	0.02	0.02
Market assumptions related to yields for comparable instruments \| Asset-backed securities \| Maximum \| Discounted cash flows \| Fair Value, Recurring
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Available for sale securities	0.03	0.03
Market assumptions related to yields for comparable instruments \| Asset-backed securities \| Weighted Average \| Discounted cash flows \| Fair Value, Recurring
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Available for sale securities	0.02	0.02

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Amount excluding accrued interest, of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Value of input used to measure investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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The aggregate of all domestic interest-bearing and noninterest-bearing deposit liabilities.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Fair value portion of loans held-for-sale including, but not limited to, mortgage loans and finance receivables.

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Amount, after deduction of unamortized premium (discount) and debt issuance cost, of long-term debt. Excludes lease obligation.

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