Taxes on Income (Tax Benefits) - Deferred Tax Assets and Liabilities in Balance Sheet (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Income Tax Contingency [Line Items]
Current deferred income tax assets, net	$ 7,824	$ 7,804
Current deferred income tax liabilities, net	(3,317)	(5,029)
Noncurrent deferred income tax assets, net	1,848	2,130
Noncurrent deferred income tax liabilities, net	(23,339)	(19,386)
Net deferred income tax liabilities	$ (16,984)	(14,481)
Bayou Perma-Pipe Canada, Ltd
Income Tax Contingency [Line Items]
Current deferred income tax liabilities, net		$ (1,500)