Supplemental Cash Flow and Non-Cash Information (Table Of Supplmental Cash Flow Information) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Supplemental Cash Flow Information [Abstract]
Income taxes paid, net	$ 2,242	$ 1,416
Interest paid	1,990	2,256
Cash Flow Non-cash Investing And Financing Activities Disclosure [Abstract]
Additions to property, plant and equipment in accounts payable	$ 1,945	$ 11,035