Revenue Recognition and Reserve for Sales Returns and Allowances - Additional Information (Detail) (USD $) In Thousands, unless otherwise specified				9 Months Ended
	Sep. 30, 2013	Dec. 31, 2012		Sep. 30, 2013 Minimum	Sep. 30, 2013 Maximum
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Discount on invoiced amount of products				1.00%	6.00%
Reserve for sales returns and allowances	$ 35,307	$ 34,373	[1]

[1] Derived from audited financial statements