Investments (HTM Year Of Issuance) (Details) $ in Millions	Sep. 30, 2020 USD ($)
Investments, Debt and Equity Securities [Abstract]
2020	$ 116
2019	18
2018	1
2017	34
2016	183
Prior	240
Total Securities	$ 592

Amount of investment in debt security measured at amortized cost (held-to-maturity) originated more than five years prior to current fiscal year.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 20
-Section 50
-Paragraph 6
-URI http://asc.fasb.org/extlink&oid=121599337&loc=SL82919232-210447

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- Definition

Amount of investment in debt security measured at amortized cost (held-to-maturity) originated four years prior to current fiscal year.

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- Definition

Amount of investment in debt security measured at amortized cost (held-to-maturity) originated in current fiscal year.

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Amount of investment in debt security measured at amortized cost (held-to-maturity) originated in fiscal year prior to current fiscal year.

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- Definition

Amount of investment in debt security measured at amortized cost (held-to-maturity) originated three years prior to current fiscal year.

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Amount of investment in debt security measured at amortized cost (held-to-maturity) originated two years prior to current fiscal year.

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Held-to-maturity securities, debt maturities, amortized cost.

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