Investments (Schedule Of Carrying Amount And Maximum Loss Exposure Of Equity Investments) (Details) - Lb Pipe Coupling Products Llc - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Schedule of Equity Method Investments
Maximum exposure to loss	$ 5,845	$ 6,008
LB Pipe JV equity method investment
Schedule of Equity Method Investments
Maximum exposure to loss	3,875	3,902
Revolving line of credit
Schedule of Equity Method Investments
Maximum exposure to loss	1,235	1,235
Net investment in direct financing lease
Schedule of Equity Method Investments
Maximum exposure to loss	$ 735	$ 871