Significant Accounting Policies - Reconciliation of Activity Related to Allowance for Sales Returns (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Accounting Policies [Abstract]
Beginning balance	$ 6,383	$ 6,521	$ 4,955
Provision	32,127	32,425	36,239
Sales returns	(31,176)	(32,563)	(34,673)
Ending balance	$ 7,334	$ 6,383	$ 6,521

For each income statement presented, the amount of estimated sales returns.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 235

-SubTopic 10

-Section 50

-Paragraph 3

-URI http://asc.fasb.org/extlink&oid=6367646&loc=d3e18780-107790

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 605

-SubTopic 15

-Section 45

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6406750&loc=d3e47468-111626

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 48

-Paragraph 6, 7, 8

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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Balance Type:	credit
Period Type:	duration