Securities (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022
Allowance for credit loss	$ 0.0		$ 0.0
Accrued interest receivable on available-for-sale debt securities	6.7		6.7		$ 3.7
Proceeds from Sale of Debt Securities, Available-for-sale	0.0	$ 0.0	0.0	$ 0.0
Held-to-maturity Securities
Specific reserve for outstanding balance of financing receivable in active forbearance	1.1		1.1		1.1
Accrued interest receivable on held-to-maturity securities	$ 0.1		$ 0.1		$ 0.1

Interest earned but not yet received by the entity on its debt securities available for sale.

No definition available.

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- Definition

Interest earned but not yet received by the entity on its debt securities held-to-maturity.

+ References

No definition available.

+ Details

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- Definition

Specific reserve for outstanding balance of financing receivable in active forbearance.

+ References

No definition available.

+ Details

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- Definition

Amount excluding accrued interest, of allowance for credit loss on 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
-Topic 326
-SubTopic 30
-Name Accounting Standards Codification
-Section 45
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479130/326-30-45-1

+ Details

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- Definition

Amount of cash inflow from sale of 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
-Topic 320
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 11
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481830/320-10-45-11

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 320
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 9
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481800/320-10-50-9

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-Name Accounting Standards Codification
-Topic 230
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-Section 45
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-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482740/230-10-45-12

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-Name Accounting Standards Codification
-Section 45
-Paragraph 11
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482740/230-10-45-11

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