Shareholders' Equity (Changes in Accumulated Other Comprehensive Loss) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance, beginning of period	$ (32,075)	$ (37,578)	$ (32,294)	$ (37,641)
Amortization	219	62	438	125
Balance, end of period	(31,856)	(37,516)	(31,856)	(37,516)
Pension Plan [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance, beginning of period	(32,223)	(37,933)	(32,443)	(38,003)
Amortization	220	69	440	139
Balance, end of period	(32,003)	(37,864)	(32,003)	(37,864)
Other Post-Employment Benefit Plans [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance, beginning of period	148	355	149	362
Amortization	(1)	(7)	(2)	(14)
Balance, end of period	$ 147	$ 348	$ 147	$ 348