Loans Receivable - Modified TDRs (Details)	12 Months Ended
Dec. 31, 2019 USD ($) contract	Dec. 31, 2018 USD ($) contract	Dec. 31, 2017 USD ($) contract
Financing Receivable, Modifications [Line Items]
Number of Contracts \| contract	17	18	12
Related Specific Valuation Allowance	$ 2,143,000	$ 4,170,000
Commercial business
Financing Receivable, Modifications [Line Items]
Related Specific Valuation Allowance	1,944,000	3,955,000
Commercial business \| Commercial and industrial
Financing Receivable, Modifications [Line Items]
Related Specific Valuation Allowance	1,372,000	2,607,000
Commercial business \| Owner-occupied commercial real estate
Financing Receivable, Modifications [Line Items]
Related Specific Valuation Allowance	426,000	1,142,000
Commercial business \| Non-owner occupied commercial real estate
Financing Receivable, Modifications [Line Items]
Related Specific Valuation Allowance	146,000	206,000
Real estate construction and land development
Financing Receivable, Modifications [Line Items]
Related Specific Valuation Allowance	0	0
Real estate construction and land development \| One-to-four family residential
Financing Receivable, Modifications [Line Items]
Related Specific Valuation Allowance	0	0
Consumer
Financing Receivable, Modifications [Line Items]
Related Specific Valuation Allowance	$ 143,000	$ 139,000
Troubled Debt Restructured Loans
Financing Receivable, Modifications [Line Items]
Number of Contracts \| contract	65	53	36
Outstanding Principal Balance	$ 35,422,000	$ 22,495,000	$ 19,200,000
Number of Contracts \| contract	17	8	5
Recorded Investment	$ 14,050,000	$ 2,620,000	$ 1,308,000
Troubled Debt Restructured Loans \| Commercial business
Financing Receivable, Modifications [Line Items]
Number of Contracts \| contract	52	38	26
Outstanding Principal Balance	$ 35,032,000	$ 21,594,000	$ 18,152,000
Number of Contracts \| contract	17	6	2
Recorded Investment	$ 14,050,000	$ 1,955,000	$ 363,000
Troubled Debt Restructured Loans \| Commercial business \| Commercial and industrial
Financing Receivable, Modifications [Line Items]
Number of Contracts \| contract	44	31	19
Outstanding Principal Balance	$ 31,129,000	$ 16,129,000	$ 7,212,000
Number of Contracts \| contract	13	5	1
Recorded Investment	$ 12,856,000	$ 1,890,000	$ 283,000
Troubled Debt Restructured Loans \| Commercial business \| Owner-occupied commercial real estate
Financing Receivable, Modifications [Line Items]
Number of Contracts \| contract	4	4	3
Outstanding Principal Balance	$ 1,695,000	$ 2,521,000	$ 1,366,000
Number of Contracts \| contract	3	1	1
Recorded Investment	$ 1,142,000	$ 65,000	$ 80,000
Troubled Debt Restructured Loans \| Commercial business \| Non-owner occupied commercial real estate
Financing Receivable, Modifications [Line Items]
Number of Contracts \| contract	4	3	4
Outstanding Principal Balance	$ 2,208,000	$ 2,944,000	$ 9,574,000
Number of Contracts \| contract	1	0	0
Recorded Investment	$ 52,000	$ 0	$ 0
Troubled Debt Restructured Loans \| Real estate construction and land development
Financing Receivable, Modifications [Line Items]
Number of Contracts \| contract	1	2	2
Outstanding Principal Balance	$ 237,000	$ 665,000	$ 938,000
Number of Contracts \| contract	0	2	2
Recorded Investment	$ 0	$ 665,000	$ 938,000
Troubled Debt Restructured Loans \| Real estate construction and land development \| One-to-four family residential
Financing Receivable, Modifications [Line Items]
Number of Contracts \| contract	1	2	2
Outstanding Principal Balance	$ 237,000	$ 665,000	$ 938,000
Initial advance at the time of modification	$ 0	$ 0	$ 0
Number of Contracts \| contract	0	2	2
Recorded Investment	$ 0	$ 665,000	$ 938,000
Troubled Debt Restructured Loans \| Real estate construction and land development \| Five or more family residential and commercial properties
Financing Receivable, Modifications [Line Items]
Number of Contracts \| contract	0	0	0
Recorded Investment	$ 0	$ 0	$ 0
Troubled Debt Restructured Loans \| Consumer
Financing Receivable, Modifications [Line Items]
Number of Contracts \| contract	12	13	8
Outstanding Principal Balance	$ 153,000	$ 236,000	$ 110,000
Number of Contracts \| contract	0	0	1
Recorded Investment	$ 0	$ 0	$ 7,000
90 Days or Greater \| Troubled Debt Restructured Loans
Financing Receivable, Modifications [Line Items]
Number of Contracts \| contract	6	1	1
Past Modified Maturity Date \| Troubled Debt Restructured Loans
Financing Receivable, Modifications [Line Items]
Number of Contracts \| contract	11	7
30-89 Days \| Troubled Debt Restructured Loans
Financing Receivable, Modifications [Line Items]
Number of Contracts \| contract			4
Modified subsequently \| Troubled Debt Restructured Loans
Financing Receivable, Modifications [Line Items]
Related Specific Valuation Allowance		$ 260,000	$ 1,000

Loans and Leases Receivable, Impaired by Modification, Initial Loan Disbursement on construction-type loans.

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

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 33
-URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953676-111524

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Number of financing receivables that have been modified by troubled debt restructurings within the previous 12 months and for which there was a payment default.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 34
-URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953682-111524

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Amount of allowance for credit losses related to recorded investment.

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
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-Topic 310
-SubTopic 10
-Section 50
-Paragraph 15
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-URI http://asc.fasb.org/extlink&oid=84173941&loc=d3e5212-111524

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