Estimated Future Amortization Expense by Year from Purchased Intangibles (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2011
Estimated future amortization expense
2012	$ 2,955
2013	2,955
2014	1,150
Finite-Lived Intangible Assets, Future Amortization Expense, Total	$ 7,060

The aggregate estimated amortization expense for succeeding fiscal years for intangible assets subject to amortization.

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 142

-Paragraph 45

-Subparagraph a(3)

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 350

-SubTopic 30

-Section 50

-Paragraph 2

-Subparagraph (a)(3)

-URI http://asc.fasb.org/extlink&oid=6905858&loc=d3e16323-109275

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Data Type:	xbrli:monetaryItemType
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Period Type:	duration