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Loans and Allowance for Credit Losses - Troubled Debt Restructuring Modifications (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2021 USD ($) loan contract	Mar. 31, 2020 USD ($) loan contract
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of Contracts Modified | contract	0	3
Pre-Modification Outstanding Recorded Investment	$ 0	$ 273
Post-Modification Outstanding Recorded Investment	0	265
Post-Modification Outstanding Recorded Investment at Period End	$ 0	$ 247
Number of modified TDR loans that defaulted | loan	0	0
Commercial and industrial | Commercial loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of Contracts Modified | contract		1
Pre-Modification Outstanding Recorded Investment		$ 170
Post-Modification Outstanding Recorded Investment		162
Post-Modification Outstanding Recorded Investment at Period End		$ 144
Installment and other consumer loans | Consumer loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of Contracts Modified | contract		2
Pre-Modification Outstanding Recorded Investment		$ 103
Post-Modification Outstanding Recorded Investment		103
Post-Modification Outstanding Recorded Investment at Period End		$ 103

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

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

+ 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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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=121611835&loc=SL6953682-111524

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Amount of increase (decrease) in financing receivable modified from troubled debt restructuring.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 33
-Subparagraph (a)(2)
-URI http://asc.fasb.org/extlink&oid=121611835&loc=SL6953676-111524

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