Shareholders' Equity (Changes in Accumulated Other Comprehensive Loss) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance, beginning of period	$ (37,641)	$ (24,932)
Amortization	247	630
Actuarial gains (losses)	5,100	(13,339)
Balance, end of period	(32,294)	(37,641)
Pension Plan [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance, beginning of period	(38,003)	(25,434)
Amortization	278	671
Actuarial gains (losses)	5,282	(13,240)
Balance, end of period	(32,443)	(38,003)
Other Post-Employment Benefit Plans [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance, beginning of period	362	502
Amortization	(31)	(41)
Actuarial gains (losses)	(182)	(99)
Balance, end of period	$ 149	$ 362