Defined Pension Plans (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Defined Benefit Plan Disclosure [Line Items]
Pension period			30 years
Defined Benefit Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension costs	$ 691	$ 1,027	$ 418	$ 2,056
Unfunded Supplemental Executive Retirement Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension costs	$ 161	$ 145	$ 321	$ 290