Shareholders' Equity (Changes in Accumulated Other Comprehensive Loss) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance, beginning of period	$ (37,641)	$ (24,932)
Amortization	63	158
Balance, end of period	(37,578)	(24,774)
Pension Plan
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance, beginning of period	(38,003)	(25,434)
Amortization	70	168
Balance, end of period	(37,933)	(25,266)
Other Post-Employment Benefit Plans
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance, beginning of period	362	502
Amortization	(7)	(10)
Balance, end of period	$ 355	$ 492