Components of Inventories (Detail) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Inventory [Line Items]
Raw materials and supplies	$ 23,934	$ 19,598
In-process inventories	8,011	5,039
Finished goods and goods for resale	122,283	152,973
Reserve for stock obsolescence	(2,115)	(2,896)
Total	$ 152,113	$ 174,714