Loans Receivable - Summary of Troubled Debt Restructurings (Detail) $ in Thousands	12 Months Ended
Dec. 31, 2019 USD ($) SecurityLoan	Sep. 30, 2020 USD ($)
Financing Receivable Modifications Number Of Contracts [Line Items]
Number Of Loans \| SecurityLoan	1
Accrual Status	$ 1,482
Total TDRs	$ 1,482	$ 0
Residential Real Estate [Member]
Financing Receivable Modifications Number Of Contracts [Line Items]
Number Of Loans \| SecurityLoan	1
Accrual Status	$ 1,482
Total TDRs	$ 1,482

Number of financing receivables that have been modified by troubled debt restructurings.

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- Definition

Financing Receivable Modifications Recorded Investment On Accrual Status

+ References

No definition available.

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- Definition

Number of financing receivables that have been modified by troubled debt restructurings.

+ References

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- Definition

Amount of financing receivable modified as troubled debt restructuring.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 33
-URI http://asc.fasb.org/extlink&oid=121611835&loc=SL6953676-111524

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 40
-Section 50
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=121585226&loc=d3e18845-111554

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