Property and Equipment: (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Property, Plant and Equipment [Line Items]
Total property and equipment, cost	$ 203,203	$ 198,773
Accumulated depreciation	(116,209)	(112,836)
Net property and equipment	86,994	85,937	[1]
Machinery and Equipment [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment, cost	79,535	78,332
Land, Buildings and Improvements [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment, cost	61,947	61,521
Molds [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment, cost	29,582	27,704
Computer Equipment and Software [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment, cost	20,296	19,611
Furniture and Fixtures [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment, cost	3,382	3,339
Construction in Progress [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment, cost	$ 8,461	$ 8,266

[1] December 31, 2012 balances were derived from audited consolidated financial statements.