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Summary of Significant Accounting Policies (Narrative) (Details) - USD ($) $ in Thousands |  | 12 Months Ended |
--- | --- | --- | ---
Jan. 01, 2019 | Dec. 31, 2019 | Dec. 31, 2018
Significant Accounting Policies [Line Items] |  |  |
Days past due when loans are generally charged-off in full, in days |  | 120 days |
Other real estate owned |  | $ 468 | $ 230
FHLB stock |  | 14,600 | 20,300
FRB stock |  | 6,100 | 6,100
Equity method investments, asset amount |  | $ 7,600 | 6,000
Number of consecutive years used for compensation calculation |  | 5 years |
Reclassification from AOCI to retained earnings | $ 2,800 |  |
Reclassification of qualified investment securities from HTM to AFS |  |  | (710)
ASU 2016-02 [Member] |  |  |
Significant Accounting Policies [Line Items] |  |  |
Cumulative-effect adjustment on assets | 22,700 |  |
Cumulative-effect adjustment on liabilities | $ 23,400 |  |
ASU 2017-12 [Member] |  |  |
Significant Accounting Policies [Line Items] |  |  |
Reclassification of qualified investment securities from HTM to AFS |  | $ 26,200 |
Other Assets [Member] |  |  |
Significant Accounting Policies [Line Items] |  |  |
Tax credit investments |  | $ 16,500 | $ 4,500
Core Deposits [Member] |  |  |
Significant Accounting Policies [Line Items] |  |  |
Estimated average life |  | 9 years 6 months |
Other Intangible Assets [Member] |  |  |
Significant Accounting Policies [Line Items] |  |  |
Estimated average life |  | 20 years |
Minimum [Member] |  |  |
Significant Accounting Policies [Line Items] |  |  |
Standby letters of credit outstanding original term, in years |  | 1 year |
Loss rate look-back period |  | 24 months |
Loss emergence period |  | 12 months |
Financing receivable increase in reserves of credit loss percentage |  | 15.00% |
Minimum [Member] | Building And Building Improvements [Member] |  |  |
Significant Accounting Policies [Line Items] |  |  |
Premise and equipment, estimated useful lives, in years |  | 15 years |
Minimum [Member] | Software, Furniture And Equipment [Member] |  |  |
Significant Accounting Policies [Line Items] |  |  |
Premise and equipment, estimated useful lives, in years |  | 3 years |
Maximum [Member] |  |  |
Significant Accounting Policies [Line Items] |  |  |
Standby letters of credit outstanding original term, in years |  | 5 years |
Loss emergence period |  | 32 months |
Financing receivable increase in reserves of credit loss percentage |  | 30.00% |
Maximum [Member] | Building And Building Improvements [Member] |  |  |
Significant Accounting Policies [Line Items] |  |  |
Premise and equipment, estimated useful lives, in years |  | 39 years |
Maximum [Member] | Software, Furniture And Equipment [Member] |  |  |
Significant Accounting Policies [Line Items] |  |  |
Premise and equipment, estimated useful lives, in years |  | 10 years |

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