Investments (Narrative) (Details) $ in Millions	Dec. 31, 2022 USD ($) security	Dec. 31, 2021 USD ($) security
Debt and Equity Securities, FV-NI [Line Items]
Number of AFS investment securities in an unrealized loss position \| security	3,562	1,302
Allowance for credit loss on HTM securities (less than)	$ 1
Available-for-sale, at fair value	11,915	$ 24,048
Asset Pledged as Collateral without Right
Debt and Equity Securities, FV-NI [Line Items]
Available-for-sale, at fair value	7,100	3,100
Securities Investment
Debt and Equity Securities, FV-NI [Line Items]
Accrued interest receivable	$ 75	$ 65

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).

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 30
-Section 45
-Paragraph 1
-URI https://asc.fasb.org/extlink&oid=124258926&loc=SL82898722-210454

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+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 6
-Subparagraph (b)(3)
-URI https://asc.fasb.org/extlink&oid=126970911&loc=d3e27290-111563

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 30
-Section 50
-Paragraph 4
-Subparagraph (b)(3)
-URI https://asc.fasb.org/extlink&oid=124269663&loc=SL82922888-210455

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+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 20
-Section 45
-Paragraph 1
-URI https://asc.fasb.org/extlink&oid=124255206&loc=SL82895884-210446

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Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
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