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Employee Benefit Plans (Narrative) (Details) - USD ($) $ in Thousands | 12 Months Ended
--- | ---
Dec. 31, 2019 | Dec. 31, 2018 | Dec. 31, 2017
Defined Benefit Plan Disclosure [Line Items] |  |  |
Contribution to pension plan in excess of minimum required contribution | $ 0 | $ 0 | $ 0
Accumulated benefit obligation | $ 76,800 | 63,300 |
Investment strategy, percentage in long-term growth | 97.00% |  |
Investment strategy, percentage in near-term benefit payments | 3.00% |  |
Maximum percentage of securities purchasing allowed of the portfolio at any time | 5.00% |  |
Maximum market value purchase percentage allowed of any one issuer | 8.00% |  |
Percentage of Plan assets | 98.00% |  |
Postretirement benefit plan, accrued liabilities | $ 110 | 109 |
Estimated future net loss for the plan that will be amortized from accumulated other comprehensive income | $ 1,300 | $ 34 |
Commercial Mortgage Back Securities And Assets Backed Securities [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Maximum percentage of securities purchasing allowed of the portfolio at any time | 10.00% |  |
Securities Less Than Aquality [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Maximum percentage of securities purchasing allowed of the portfolio at any time | 13.00% |  |
Minimum [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Percentage of portfolio invest directly or indirectly | 35.00% |  |
Percentage of remaining portfolio invest directly or indirectly | 10.00% |  |
Maximum [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Percentage of portfolio invest directly or indirectly | 90.00% |  |
Percentage of remaining portfolio invest directly or indirectly | 65.00% |  |
Portfolio Concentration Commingled Trust Fund1 [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Percentage of Plan assets |  | 15.00% |
Portfolio Concentration Commingled Trust Fund2 [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Percentage of Plan assets |  | 6.00% |
Portfolio Concentration Short Term Investment Fund [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Percentage of Plan assets |  | 6.00% |
SERP [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Unfunded pension liability | $ 1,700 | $ 1,700 |
Pension expense | $ 366 | $ 215 | $ 194
Investment Firm One [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Portfolio management, controlled percentage | 98.00% | 62.00% |
Defined Benefit Plan [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Portfolio management, controlled percentage | 2.00% | 2.00% |
Investment Firm Two [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Portfolio management, controlled percentage |  | 36.00% |

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