Employee Benefits (Schedule of fair value of pension plan assets, by fair value hierarchy) (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	$ 20,354	$ 17,459
Pension Plan | Investment in separate accounts fixed income
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	15,542	13,638
Pension Plan | Investment in separate accounts equity
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	4,812	3,821
Level 1 | Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	0	0
Level 1 | Pension Plan | Investment in separate accounts fixed income
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	0	0
Level 1 | Pension Plan | Investment in separate accounts equity
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	0	0
Level 2 | Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	20,354	17,459
Level 2 | Pension Plan | Investment in separate accounts fixed income
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	15,542	13,638
Level 2 | Pension Plan | Investment in separate accounts equity
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	4,812	3,821
Level 3 | Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	0	0
Level 3 | Pension Plan | Investment in separate accounts fixed income
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	0	0
Level 3 | Pension Plan | Investment in separate accounts equity
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	$ 0	$ 0