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, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Supplemental Cash Flow Information [Abstract]
Income taxes paid, net	$ 2,524	$ 1,674	$ 5,049	$ 6,494
Interest paid	$ 2,089	$ 2,114	6,385	6,296
Cash Flow Non-cash Investing And Financing Activities Disclosure [Abstract]
Additions to property, plant and equipment in accounts payable			$ 6,024	$ 1,004