Stock-Based Compensation (Details 4) In Thousands, unless otherwise specified	Dec. 31, 2011
Stock-Based Compensation
Reserved shares of common stock for future issuance	10,411
2009 Stock Incentive Plan
Stock-Based Compensation
Reserved shares of common stock for future issuance	6,350
2000 Stock Incentive Plan
Stock-Based Compensation
Reserved shares of common stock for future issuance	3,055
2009 Employee Stock Purchase Plan
Stock-Based Compensation
Reserved shares of common stock for future issuance	1,006

Aggregate number of common shares reserved for future issuance.

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 129

-Paragraph 4

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.29)

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant