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Variable Interest Entities and Securitizations - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Variable Interest Entity [Line Items]
Amortization method qualified affordable housing investments, amortization	$ 554	$ 477
Affordable housing tax credits	610	529
Amortization method qualified affordable housing investments	4,400	4,200
Qualified affordable housing investments, commitment	1,500	1,500
VIE, unconsolidated, carrying amount, assets	5,127	4,802
VIE, consolidated, carrying amount, assets	35,519	35,556
VIE, reporting entity involvement, maximum loss exposure	5,413	5,145
Affordable housing entities
Variable Interest Entity [Line Items]
VIE, unconsolidated, carrying amount, assets	4,559	4,238
Total assets of the unconsolidated VIE investment funds	10,900	10,800
VIE, consolidated, carrying amount, assets	236	243
VIE, reporting entity involvement, maximum loss exposure	4,559	4,238
Entities that provide capital to low-income and rural communities
Variable Interest Entity [Line Items]
VIE, unconsolidated, carrying amount, assets	0	0
VIE, consolidated, carrying amount, assets	1,889	1,739
VIE, reporting entity involvement, maximum loss exposure	0	0
Other
Variable Interest Entity [Line Items]
VIE, unconsolidated, carrying amount, assets	502	353
VIE, consolidated, carrying amount, assets	0	0
VIE, reporting entity involvement, maximum loss exposure	$ 502	$ 353

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Amount of affordable housing tax credits and other tax benefits recognized.

+ References

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-SubTopic 740
-Section 50
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Amount of investment in qualified affordable housing projects.

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Amount of commitment or contingent commitments to qualified affordable housing project investments.

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Carrying amount of the assets in the reporting entity's statement of financial position that relate to the reporting entity's variable interest in the Variable Interest Entity (VIE), where the reporting entity is not the VIE's primary beneficiary.

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