Inventory Stated at Lower of Cost (First- in, First- out) or Market (Detail) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Inventory [Line Items]
Raw materials	$ 3,445	$ 3,296
Finished goods	55,674	56,394
Inventory	$ 59,119	$ 59,690	[1]

[1] Derived from audited financial statements