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Loans and Allowance for Credit Losses - Schedule of Loans by Class (Details) - USD ($) $ in Thousands | Dec. 31, 2020 | Sep. 30, 2020 | Dec. 31, 2019
--- | --- | --- | ---
Financing Receivable, Allowance for Credit Loss [Line Items] |  |  |  |
Loans, at amortized cost |  | $ 2,088,556 |  | $ 1,843,286
Allowance for credit losses |  | (22,874) | $ (22,113) | (16,677)
Loans, net of allowance for credit losses | [1] | 2,065,682 |  | 1,826,609
Deferred loan fees |  | (4,900) |  | 983
Unrecognized purchase discounts on non-PCI loans |  | 815 |  | 958
Financing receivable, accrued interest, net |  | 8,800 |  | 7,700
Commercial | Commercial and industrial |  |  |  |
Financing Receivable, Allowance for Credit Loss [Line Items] |  |  |  |
Loans, at amortized cost |  | 498,408 |  | 246,687
Allowance for credit losses |  | (2,530) | (2,525) |
Commercial real estate | Commercial real estate, owner-occupied |  |  |  |
Financing Receivable, Allowance for Credit Loss [Line Items] |  |  |  |
Loans, at amortized cost |  | 304,963 |  | 308,824
Allowance for credit losses |  | (2,778) | (3,135) |
Commercial real estate | Commercial real estate, investor-owned |  |  |  |
Financing Receivable, Allowance for Credit Loss [Line Items] |  |  |  |
Loans, at amortized cost |  | 961,208 |  | 946,317
Allowance for credit losses |  | (12,682) | (11,624) |
Commercial real estate | Construction |  |  |  |
Financing Receivable, Allowance for Credit Loss [Line Items] |  |  |  |
Loans, at amortized cost |  | 73,046 |  | 61,095
Allowance for credit losses |  | (1,557) | (860) |
Residential loans | Home equity |  |  |  |
Financing Receivable, Allowance for Credit Loss [Line Items] |  |  |  |
Loans, at amortized cost |  | 104,813 |  | 116,024
Allowance for credit losses |  | (738) | (1,038) |
Residential loans | Other residential |  |  |  |
Financing Receivable, Allowance for Credit Loss [Line Items] |  |  |  |
Loans, at amortized cost |  | 123,395 |  | 136,657
Allowance for credit losses |  | (998) | (1,260) |
Consumer loans | Installment and other consumer |  |  |  |
Financing Receivable, Allowance for Credit Loss [Line Items] |  |  |  |
Loans, at amortized cost |  | 22,723 |  | $ 27,682
Allowance for credit losses |  | $ (291) | $ (406) |
[1] | Refer to Note 1, Summary of Accounting Policies, for information on the adoption of ASU 2016-13 in 2020.

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