Supplemental Cash Flow and Non-Cash Information (Table Of Supplmental Cash Flow Information) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Supplemental Cash Flow Information [Abstract]
Income taxes paid, net	$ 11,629	$ 2,091	$ 14,596	$ 16,375
Interest paid	$ 2,364	$ 2,333	6,791	6,355
Cash Flow Non-cash Investing And Financing Activities Disclosure [Abstract]
Additions to property, plant and equipment in accounts payable			$ 6,531	$ 2,370