Shareholders' Equity (Changes in Accumulated Other Comprehensive Loss) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance, beginning of period	$ (31,856)	$ (37,516)	$ (32,294)	$ (37,641)
Amortization	219	63	657	188
Balance, end of period	(31,637)	(37,453)	(31,637)	(37,453)
Pension Plan [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance, beginning of period	(32,003)	(37,864)	(32,443)	(38,003)
Amortization	220	70	660	209
Balance, end of period	(31,783)	(37,794)	(31,783)	(37,794)
Other Post-Employment Benefit Plans [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance, beginning of period	147	348	149	362
Amortization	(1)	(7)	(3)	(21)
Balance, end of period	$ 146	$ 341	$ 146	$ 341