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Significant Accounting Policies - Impact of Topic 326 (Details) - USD ($) $ in Thousands | Sep. 30, 2020 | Jan. 01, 2020
--- | --- | ---
Allowance-debt securities available for sale |  |
Accrued interest receivable for debt securities available for sale debt | $ 6,900 |
Accounting Standards Update 2016-13 |  |
Assets |  |
Portfolio Loans, allowance for loan losses (in dollars) |  | $ 53,748
Accounting Standards Update 2016-13 | Cumulative Effect, Period of Adoption, Adjusted Balance |  |
Assets |  |
Portfolio Loans, allowance for loan losses (in dollars) |  | 70,581
Liabilities |  |
Reserve for off-balance-sheet credit exposures |  | 5,492
Accounting Standards Update 2016-13 | Cumulative Effect, Period of Adoption, Adjustment |  |
Assets |  |
Portfolio Loans, allowance for loan losses (in dollars) |  | 16,833
Liabilities |  |
Reserve for off-balance-sheet credit exposures |  | 5,492
Commercial Loans | Accounting Standards Update 2016-13 |  |
Assets |  |
Portfolio Loans, allowance for loan losses (in dollars) |  | 18,291
Commercial Loans | Accounting Standards Update 2016-13 | Cumulative Effect, Period of Adoption, Adjusted Balance |  |
Assets |  |
Portfolio Loans, allowance for loan losses (in dollars) |  | 19,006
Commercial Loans | Accounting Standards Update 2016-13 | Cumulative Effect, Period of Adoption, Adjustment |  |
Assets |  |
Portfolio Loans, allowance for loan losses (in dollars) |  | 715
Commercial Real Estate Loans | Accounting Standards Update 2016-13 |  |
Assets |  |
Portfolio Loans, allowance for loan losses (in dollars) |  | 21,190
Commercial Real Estate Loans | Accounting Standards Update 2016-13 | Cumulative Effect, Period of Adoption, Adjusted Balance |  |
Assets |  |
Portfolio Loans, allowance for loan losses (in dollars) |  | 30,496
Commercial Real Estate Loans | Accounting Standards Update 2016-13 | Cumulative Effect, Period of Adoption, Adjustment |  |
Assets |  |
Portfolio Loans, allowance for loan losses (in dollars) |  | 9,306
Real Estate Construction | Accounting Standards Update 2016-13 |  |
Assets |  |
Portfolio Loans, allowance for loan losses (in dollars) |  | 3,204
Real Estate Construction | Accounting Standards Update 2016-13 | Cumulative Effect, Period of Adoption, Adjusted Balance |  |
Assets |  |
Portfolio Loans, allowance for loan losses (in dollars) |  | 6,158
Real Estate Construction | Accounting Standards Update 2016-13 | Cumulative Effect, Period of Adoption, Adjustment |  |
Assets |  |
Portfolio Loans, allowance for loan losses (in dollars) |  | 2,954
Retail Real Estate | Accounting Standards Update 2016-13 |  |
Assets |  |
Portfolio Loans, allowance for loan losses (in dollars) |  | 10,495
Retail Real Estate | Accounting Standards Update 2016-13 | Cumulative Effect, Period of Adoption, Adjusted Balance |  |
Assets |  |
Portfolio Loans, allowance for loan losses (in dollars) |  | 13,787
Retail Real Estate | Accounting Standards Update 2016-13 | Cumulative Effect, Period of Adoption, Adjustment |  |
Assets |  |
Portfolio Loans, allowance for loan losses (in dollars) |  | 3,292
Retail Other | Accounting Standards Update 2016-13 |  |
Assets |  |
Portfolio Loans, allowance for loan losses (in dollars) |  | 568
Retail Other | Accounting Standards Update 2016-13 | Cumulative Effect, Period of Adoption, Adjusted Balance |  |
Assets |  |
Portfolio Loans, allowance for loan losses (in dollars) |  | 1,134
Retail Other | Accounting Standards Update 2016-13 | Cumulative Effect, Period of Adoption, Adjustment |  |
Assets |  |
Portfolio Loans, allowance for loan losses (in dollars) |  | $ 566

X
- Definition Amount, after tax, of accumulated unrealized gain (loss) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale) with allowance for credit loss. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 30 -Section 45 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=121558606&loc=SL82922866-210454 + Details
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- Definition Amount of allowance to cover probable credit losses on loans and leases. Includes carryover of or adjustments to the allowance for loan losses in connection with business combinations. Excludes allowance for loans and leases covered under loss sharing agreements. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 11B -Subparagraph (g) -URI http://asc.fasb.org/extlink&oid=121611835&loc=SL6953423-111524 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 30 -Section 50 -Paragraph 2 -Subparagraph (b)(1)(ii) -URI http://asc.fasb.org/extlink&oid=121614798&loc=d3e15032-111544 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 11B -Subparagraph (c)(1) -URI http://asc.fasb.org/extlink&oid=121611835&loc=SL6953423-111524 Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section S99 -Paragraph 4 -Subparagraph (SAB Topic 6.L.1) -URI http://asc.fasb.org/extlink&oid=27010918&loc=d3e74567-122707 + Details
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