Supplemental Cash Flow and Non-Cash Information (Table Of Supplmental Cash Flow Information) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Supplemental Cash Flow Information [Abstract]
Income taxes paid, net	$ 1,709	$ 2,703	$ 2,525	$ 4,820
Interest paid	$ 2,082	$ 2,113	4,296	4,182
Cash Flow Non-cash Investing And Financing Activities Disclosure [Abstract]
Additions to property, plant and equipment in accounts payable			$ 2,074	$ 1,291