Schedule Of Accounts Receivable, Net (Detail) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable, gross	$ 127,123	$ 146,682
Allowance for sales returns	3,523	4,423
Allowance for doubtful accounts	3,099	2,522
Accounts receivable, net	$ 120,501	$ 139,737