Segment Information (Details 1) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Summary of revenue by net geographic region
United States	$ 244,897	$ 209,583	$ 162,023
International	304,435	213,761	157,543
Net revenue	$ 549,332	$ 423,344	$ 319,566

Revenues from external customers attributed to all foreign countries in total from which the entity derives revenues.

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 131

-Paragraph 38

-Subparagraph a(2)

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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 280

-SubTopic 10

-Section 50

-Paragraph 41

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=6534315&loc=d3e9038-108599

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration