Employee Benefits (Schedule of fair value of pension plan assets, by fair value hierarchy) (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	$ 22,634	$ 20,628
Defined Benefit Pension Plan | Investment in separate accounts fixed income
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	15,189	14,143
Defined Benefit Pension Plan | Investment in separate accounts equity
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	6,206	5,256
Defined Benefit Pension Plan | Investment in separate accounts other
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	1,239	1,229
Quoted Prices in Active Markets for Identical Assets (Level 1) | Defined Benefit Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	22,634	20,628
Quoted Prices in Active Markets for Identical Assets (Level 1) | Defined Benefit Pension Plan | Investment in separate accounts fixed income
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	15,189	14,143
Quoted Prices in Active Markets for Identical Assets (Level 1) | Defined Benefit Pension Plan | Investment in separate accounts equity
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	6,206	5,256
Quoted Prices in Active Markets for Identical Assets (Level 1) | Defined Benefit Pension Plan | Investment in separate accounts other
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	$ 1,239	$ 1,229