Investment Securities (Narrative) (Details) $ in Millions	3 Months Ended
Mar. 31, 2023 USD ($) security	Mar. 31, 2022 USD ($)	Dec. 31, 2022 USD ($)
Securities with no credit impairment in unrealized loss position \| security	1,269
Loan interest receivable	$ 45		$ 49
Securities gains and losses	0	$ 0
Carrying value of securities pledged	18,100
Federal reserve bank pledges	9,700
Pledged to the FHLB as collateral for potential future borrowings	6,600
Collateral for potential future borrowings	1,800
Liabilities secured by pledged collateral	$ 709
U.S. Treasury securities
Securities with no credit impairment in unrealized loss position \| security	23
Residential mortgage-backed securities
Securities with no credit impairment in unrealized loss position \| security	993
Commercial mortgage-backed securities
Securities with no credit impairment in unrealized loss position \| security	253

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+ References

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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).

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Amount of the collateral pledged in support of federal home loan bank advances outstanding.

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