Other Assets and Liabilities - Additional Information (Detail) $ in Thousands	3 Months Ended	12 Months Ended
Mar. 31, 2025 USD ($) loan	Mar. 31, 2025 USD ($) security_loan	Mar. 31, 2025 USD ($)	Mar. 31, 2024 USD ($)	Dec. 31, 2024 USD ($) loan	Dec. 31, 2024 USD ($) security_loan
Financing Receivable, Allowance for Credit Loss [Line Items]
Current expected credit loss reserves for unfunded loan commitments	$ 10,487	$ 10,487	$ 10,487	$ 12,600	$ 10,412	$ 10,412
Number of loans	138	138			130	130
Increase (decrease) in reserve			75	$ (2,700)
Unfunded Loan Commitments
Financing Receivable, Allowance for Credit Loss [Line Items]
Current expected credit loss reserves for unfunded loan commitments	$ 1,033,229	$ 1,033,229	$ 1,033,229		$ 1,263,068	$ 1,263,068
Number of loans \| loan	57

Financing Receivable, Number Of Loans

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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/2003/role/disclosureRef
-Name Regulation S-K (SK)
-Number 229
-Section 1405
-Paragraph c
-Publisher SEC

Reference 2: 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

Amount of expected credit loss for credit exposure on off-balance-sheet commitment, including but not limited to, loan commitment, standby letter of credit, financial guarantee not accounted for as insurance. Excludes off-balance sheet credit exposure accounted for as insurance and instrument accounted for under derivatives and hedging.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 45
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479344/326-20-45-2

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 460
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482454/460-10-45-1

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- Definition

Amount of expense (reversal of expense) for expected credit loss for off-balance sheet credit exposure. Excludes off-balance sheet credit exposure accounted for as insurance and instrument accounted for under derivatives and hedging.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479319/326-20-50-13

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