Loans and Allowance for Credit Losses - Restructured Loans that are Considered to be in Default (Details) $ in Thousands	12 Months Ended
Dec. 31, 2019 USD ($) loan	Dec. 31, 2018 USD ($) loan	Dec. 31, 2017 USD ($) loan
Financing Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Troubled Debt Restructuring, Subsequent Default, Number of Contracts \| loan	0	1	1
Financing Receivable, Troubled Debt Restructuring, Subsequent Default \| $	$ 0	$ 49	$ 2
Residential Portfolio Segment [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Troubled Debt Restructuring, Subsequent Default, Number of Contracts \| loan	0	1	0
Financing Receivable, Troubled Debt Restructuring, Subsequent Default \| $	$ 0	$ 49	$ 0
Loans To Individuals [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Troubled Debt Restructuring, Subsequent Default, Number of Contracts \| loan	0	0	1
Financing Receivable, Troubled Debt Restructuring, Subsequent Default \| $	$ 0	$ 0	$ 2

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No definition available.

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- Definition

Number of financing receivable contracts modified as troubled debt restructuring within previous 12 months, with subsequent payment default.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 34
-URI http://asc.fasb.org/extlink&oid=118936363&loc=SL6953682-111524

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- Definition

Amount of financing receivable modified as troubled debt restructuring within previous 12 months, with subsequent payment default.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 34
-Subparagraph (a)(2)
-URI http://asc.fasb.org/extlink&oid=118936363&loc=SL6953682-111524

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