Inventories: (Details) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Inventory Disclosure [Abstract]
Raw material	$ 23,559	$ 23,006
Work in process	5,233	3,546
Finished goods	11,889	10,381
Total	$ 40,681	$ 36,933	[1]

[1] December 31, 2014 balances were derived from audited consolidated financial statements.