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Investment Securities - Narrative (Detail) - USD ($)	3 Months Ended	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2024	Dec. 31, 2023
Debt Securities, Held-to-maturity, Allowance for Credit Loss [Line Items]
Increase (decrease) in gross unrealized losses		$ (33,500,000)
Securities held-to-maturity	$ 0	$ 0	$ 0
Corporate debt
Debt Securities, Held-to-maturity, Allowance for Credit Loss [Line Items]
Investment securities available-for-sale, at fair value (1)	$ 900,000

X

- Definition

Amount, excluding accrued interest, of increase (decrease) in allowance for credit loss 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/2009/role/commonPracticeRef
-Topic 326
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 9
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479106/326-30-50-9

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- Definition

Amount excluding accrued interest, of investment in debt security measured at amortized cost (held-to-maturity) on nonaccrual status.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 16
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479319/326-20-50-16

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479319/326-20-50-13

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- Definition

Debt Securities, Available-for-Sale, Increase (Decrease) in Unrealized Losses

+ References

No definition available.

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