Discontinued Operations (Opta Minerals Inc Major Classes of Assets and Liabilities) (Details) - Opta Minerals Inc [Member] $ in Thousands	Jan. 02, 2016 USD ($)
Disposal Group, Including Discontinued Operation, Assets [Abstract]
Cash and Cash Equivalents	$ 1,707
Accounts receivables	14,676
Inventories	25,869
Property, Plant and Equipment	16,019
Intangible Assets	13,194
Other assets	3,380
Loss recognized on classification as held for sale	(10,515)
Total assets held for sale	64,330
Disposal Group, Including Discontinued Operation, Liabilities [Abstract]
Bank Indebtedness	12,107
Accounts Payable and Accrued Liabilities	9,634
Long-term Debt	25,858
Other Liabilities	4,887
Total liabilities held for sale	$ 52,486