Loans and Allowance for Credit Losses - Loans Restructured as TDRs, Excluding Loans Acquired, Segregated by Class of Loans (Details) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2020 USD ($) loan	Sep. 30, 2019 USD ($) loan	Sep. 30, 2020 USD ($) loan	Sep. 30, 2019 USD ($) loan
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of loans \| loan	5	1	5	1
Balance Prior to TDR	$ 1,948	$ 330	$ 1,948	$ 330
Balance	1,896	330	1,896	330
Financial Impact on Date of Restructure	0	0	0	0
Change in Maturity Date
Financing Receivable, Troubled Debt Restructuring [Line Items]
Balance	1,896	330	1,896	330
Change in Rate
Financing Receivable, Troubled Debt Restructuring [Line Items]
Balance	$ 0	$ 0	$ 0	$ 0
Single family residential \| Real Estate
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of loans \| loan	5	1	5	1
Balance Prior to TDR	$ 1,948	$ 330	$ 1,948	$ 330
Balance	1,896	330	1,896	330
Financial Impact on Date of Restructure	0	0	0	0
Single family residential \| Real Estate \| Change in Maturity Date
Financing Receivable, Troubled Debt Restructuring [Line Items]
Balance	1,896	330	1,896	330
Single family residential \| Real Estate \| Change in Rate
Financing Receivable, Troubled Debt Restructuring [Line Items]
Balance	$ 0	$ 0	$ 0	$ 0

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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

No definition available.

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- Definition

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

+ 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

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- Definition

Amount, after troubled debt restructuring, of modified financing receivable.

+ References

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- Definition

Amount, before troubled debt restructuring, of financing receivable to be modified.

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