v3.20.1

Employee Benefit Plans (Fair Value Of Pension Plan Assets) (Details) - Pension Plan [Member] - USD ($) $ in Thousands | Dec. 31, 2019 | Dec. 31, 2018 | Dec. 31, 2017
--- | --- | --- | ---
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | $ 249,293 | $ 197,590 | $ 198,686
Quoted Prices In Active Markets For Identical Assets (Level 1) [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 249,117 | 197,401 |
Significant Unobservable Inputs (Level 3) [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 176 | 189 |
Small-Cap Fund [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 5,087 | 3,816 |
Small-Cap Fund [Member] | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 5,087 | 3,816 |
Mid-Cap Fund [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 5,095 | 3,811 |
Mid-Cap Fund [Member] | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 5,095 | 3,811 |
Large-Cap Fund [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 40,884 | 30,595 |
Large-Cap Fund [Member] | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 40,884 | 30,595 |
International Equity Fund [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 25,580 | 19,471 |
International Equity Fund [Member] | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 25,580 | 19,471 |
Short-Term Bond Fund [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 3,590 | 9,242 |
Short-Term Bond Fund [Member] | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 3,590 | 9,242 |
Intermediate-Term Bond Funds [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 29,485 | 23,036 |
Intermediate-Term Bond Funds [Member] | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 29,485 | 23,036 |
Long-Term Investment Grade Bond Fund [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 132,096 | 99,118 |
Long-Term Investment Grade Bond Fund [Member] | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 132,096 | 99,118 |
Short-Term Investment Fund [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 7,300 | 8,312 |
Short-Term Investment Fund [Member] | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 7,300 | 8,312 |
Group Annuity Contract [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 176 | 189 |
Group Annuity Contract [Member] | Significant Unobservable Inputs (Level 3) [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | $ 176 | $ 189 |

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