Loans Held for Investment and Allowance for Credit Losses on Loans - Purchased Credit Deteriorated Loans (Detail) - Loans Acquired with Deteriorated Credit Quality [Member] $ in Thousands	12 Months Ended
Dec. 31, 2020 USD ($)
Financing Receivable Allowance For Credit Losses [Line Items]
Purchase price of loans at acquisition	$ 1,761
Allowance for credit losses at acquisition	502
Par value of acquired loans at acquisition	$ 2,263

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.

No definition available.

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- Definition

Amount of allowance for credit loss at acquisition date of financing receivable purchased with credit deterioration.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 20
-Section 50
-Paragraph 19
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=121599337&loc=SL82919265-210447

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
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- Definition

Amount at par value of financing receivable purchased with credit deterioration.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 20
-Section 50
-Paragraph 19
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=121599337&loc=SL82919265-210447

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- Definition

Amount at purchase price of financing receivable purchased with credit deterioration.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 20
-Section 50
-Paragraph 19
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=121599337&loc=SL82919265-210447

+ Details

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