Property and Equipment: (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Property, Plant and Equipment [Line Items]
Total property and equipment, cost	$ 224,026	$ 224,714
Accumulated depreciation	(141,738)	(138,623)
Net property and equipment	82,288	86,091	[1]
Machinery and Equipment [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment, cost	90,630	90,744
Land, Buildings and Improvements [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment, cost	70,231	71,415
Molds [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment, cost	33,349	33,166
Computer Equipment and Software [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment, cost	23,488	23,228
Furniture and Fixtures [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment, cost	3,450	3,571
Construction in Progress [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment, cost	$ 2,878	$ 2,590

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