Investment Securities - Held-to-Maturity Securities (Details) - USD ($)	3 Months Ended	9 Months Ended
Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021	Dec. 31, 2021
Investments, Debt and Equity Securities [Abstract]
Purchase of HTM securities	$ 0	$ 0	$ 0	$ 0
Sale of HTM securities	0	$ 0	0	$ 0
Collateral pledged
Schedule of Held-to-maturity Securities [Line Items]
Investment securities pledged	$ 596,000,000		$ 596,000,000		$ 1,500,000,000

Amount of restricted 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/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 954
-SubTopic 210
-Section 45
-Paragraph 4
-URI https://asc.fasb.org/extlink&oid=120413173&loc=SL6242262-115580

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 860
-SubTopic 30
-Section 50
-Paragraph 1A
-Subparagraph (b)(1)(i)
-URI https://asc.fasb.org/extlink&oid=109249958&loc=SL6224234-111729

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 954
-SubTopic 210
-Section 50
-Paragraph 2
-URI https://asc.fasb.org/extlink&oid=127002003&loc=SL6242269-115581

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Amount of cash outflow through purchase of long-term held-to-maturity securities.

+ References

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 13
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-Name Accounting Standards Codification
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The cash inflow associated with the sale of securities that had been designated as held-to-maturity. Excludes proceeds from maturities, prepayments and calls by the issuer.

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