Employee Benefits (Schedule of fair value of pension plan assets, by fair value hierarchy) (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	$ 20,628	$ 17,459
Defined Benefit Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value		17,459
Defined Benefit Pension Plan | Investment in separate accounts fixed income
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	15,372	13,638
Defined Benefit Pension Plan | Investment in separate accounts equity
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	5,256	3,821
Significant Observable Inputs (Level 1) | Defined Benefit Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	20,628	17,459
Significant Observable Inputs (Level 1) | Defined Benefit Pension Plan | Investment in separate accounts fixed income
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	15,372	13,638
Significant Observable Inputs (Level 1) | Defined Benefit Pension Plan | Investment in separate accounts equity
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	$ 5,256	$ 3,821