Investments (Schedule Of Carrying Amount And Maximum Loss Exposure Of Equity Investments) (Details) - LB Pipe JV [Member] - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Schedule of Equity Method Investments [Line Items]
Maximum exposure to loss	$ 6,008	$ 6,241
LB Pipe JV equity method investment [Member]
Schedule of Equity Method Investments [Line Items]
Maximum exposure to loss	3,902	5,246
Loan receivable [Member]
Schedule of Equity Method Investments [Line Items]
Maximum exposure to loss	1,235
Net investment in direct financing lease [Member]
Schedule of Equity Method Investments [Line Items]
Maximum exposure to loss	$ 871	$ 995