Property and Equipment: (Details) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Property, Plant and Equipment [Line Items]
Total property and equipment, cost	$ 227,031	$ 224,714
Accumulated depreciation	(145,655)	(138,623)
Net property and equipment	81,376	86,091	[1]
Machinery and Equipment [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment, cost	91,651	90,744
Land, Buildings and Improvements [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment, cost	70,583	71,415
Molds [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment, cost	33,417	33,166
Computer Equipment and Software [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment, cost	23,750	23,228
Furniture and Fixtures [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment, cost	3,490	3,571
Construction in Progress [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment, cost	$ 4,140	$ 2,590

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