Loans and Allowance for Credit Losses - Impaired loans, by class of loan (Details) $ in Thousands	12 Months Ended
Dec. 31, 2019 USD ($)
Loans and Leases Receivable Disclosure [Line Items]
Unpaid Contractual Principal Balance	$ 54,883
Recorded Investment With No Allowance	35,235
Recorded Investment With Allowance	19,648
Total Recorded Investment	54,883
Related Allowance	9,124
Average Recorded Investment	54,258
Interest Income Recognized	941
Commercial
Loans and Leases Receivable Disclosure [Line Items]
Unpaid Contractual Principal Balance	15,814
Recorded Investment With No Allowance	11,858
Recorded Investment With Allowance	3,956
Total Recorded Investment	15,814
Related Allowance	5,714
Average Recorded Investment	15,682
Interest Income Recognized	270
Income producing - commercial real estate
Loans and Leases Receivable Disclosure [Line Items]
Unpaid Contractual Principal Balance	14,093
Recorded Investment With No Allowance	2,713
Recorded Investment With Allowance	11,380
Total Recorded Investment	14,093
Related Allowance	2,145
Average Recorded Investment	18,133
Interest Income Recognized	382
Owner occupied - commercial real estate
Loans and Leases Receivable Disclosure [Line Items]
Unpaid Contractual Principal Balance	7,349
Recorded Investment With No Allowance	6,388
Recorded Investment With Allowance	961
Total Recorded Investment	7,349
Related Allowance	415
Average Recorded Investment	6,107
Interest Income Recognized	197
Real estate mortgage - residential
Loans and Leases Receivable Disclosure [Line Items]
Unpaid Contractual Principal Balance	5,631
Recorded Investment With No Allowance	3,175
Recorded Investment With Allowance	2,456
Total Recorded Investment	5,631
Related Allowance	650
Average Recorded Investment	5,638
Interest Income Recognized	0
Construction - commercial and residential
Loans and Leases Receivable Disclosure [Line Items]
Unpaid Contractual Principal Balance	11,509
Recorded Investment With No Allowance	11,101
Recorded Investment With Allowance	408
Total Recorded Investment	11,509
Related Allowance	100
Average Recorded Investment	8,211
Interest Income Recognized	92
Home equity
Loans and Leases Receivable Disclosure [Line Items]
Unpaid Contractual Principal Balance	487
Recorded Investment With No Allowance	0
Recorded Investment With Allowance	487
Total Recorded Investment	487
Related Allowance	100
Average Recorded Investment	487
Other consumer
Loans and Leases Receivable Disclosure [Line Items]
Average Recorded Investment	$ 0

Average amount of investment of impaired financing receivables with related allowance for credit losses and without a related allowance for credit losses.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 15
-Subparagraph (c)(1)
-URI http://asc.fasb.org/extlink&oid=121611835&loc=d3e5212-111524

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 17
-URI http://asc.fasb.org/extlink&oid=121611835&loc=d3e5258-111524

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 14A
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=121611835&loc=SL6953550-111524

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