Inventories: (Details) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Inventory Disclosure [Abstract]
Raw material	$ 21,885	$ 23,006
Work in process	4,509	3,546
Finished goods	11,837	10,381
Total	$ 38,231	$ 36,933	[1]

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