Investment Securities (Securities - Additional Information) (Detail) - USD ($) $ in Millions	Mar. 31, 2020	Dec. 31, 2019
Investment Holdings
Securities with a fair value, pledged as collateral	$ 10,600	$ 8,100
Available-for-sale securities, accumulated gross unrealized loss, before tax	110	$ 43
Accrued interest receivables on investment securities	94
Available-for-sale Securities \| Non-rated Securities
Investment Holdings
Available-for-sale securities, accumulated gross unrealized loss, before tax	$ 5

Interest, dividends, rents, ancillary and other revenues earned but not yet received by the entity on its investments.

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

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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-SubTopic 30
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