Property and Equipment: (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013
Property, Plant and Equipment [Line Items]
Total property and equipment, cost	$ 219,596	$ 213,001
Accumulated depreciation	(129,217)	(125,140)
Net property and equipment	90,379	87,861	[1]
Machinery and Equipment [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment, cost	87,318	84,317
Land, Buildings and Improvements [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment, cost	64,310	64,238
Molds [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment, cost	31,894	30,813
Computer Equipment and Software [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment, cost	21,777	21,625
Furniture and Fixtures [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment, cost	3,655	3,552
Construction in Progress [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment, cost	$ 10,642	$ 8,456

[1] December 31, 2013 balances were derived from audited consolidated financial statements.