v2.4.0.6

Marketable Securities (Tables) | 12 Months Ended
--- | ---
Dec. 31, 2011
Marketable Securities |
Schedule of estimated fair value of available-for-sale debt securities and money market funds |
|  | December 31, 2011 |  | December 31, 2010 |
--- | --- | --- | --- | --- | ---
(in thousands) |  | Amortized Cost |  | Gross Unrealized Gains |  | Gross Unrealized Losses |  | Estimated Fair Value |  | Amortized Cost |  | Gross Unrealized Gains |  | Gross Unrealized Losses |  | Estimated Fair Value |
U.S. government securities |  | $ | 66,150 |  | $ | 24 |  | $ | — |  | $ | 66,174 |  | $ | 25,966 |  | $ | 10 |  | $ | — |  | $ | 25,976 |
U.S. government agencies |  |  | 93,183 |  |  | 9 |  |  | (17 | ) |  | 93,175 |  |  | 54,625 |  |  | 30 |  |  | (7 | ) |  | 54,648 |
U.S. corporate notes |  |  | 2,707 |  |  | — |  |  | (2 | ) |  | 2,705 |  |  | 34,695 |  |  | 9 |  |  | (9 | ) |  | 34,695 |
U.S. commercial paper |  |  | 34,973 |  |  | 3 |  |  | — |  |  | 34,976 |  |  | 97,221 |  |  | — |  |  | — |  |  | 97,221 |
Money market funds |  |  | 38,721 |  |  | — |  |  | — |  |  | 38,721 |  |  | 91,805 |  |  | — |  |  | — |  |  | 91,805 |
Total |  |  | 235,734 |  |  | 36 |  |  | (19 | ) |  | 235,751 |  |  | 304,312 |  |  | 49 |  |  | (16 | ) |  | 304,345 |
Less amounts classified as cash equivalents |  |  | (38,721 | ) |  | — |  |  | — |  |  | (38,721 | ) |  | (157,151 | ) |  | — |  |  | — |  |  | (157,151 | )
Less amounts classified as restricted cash |  |  | (893 | ) |  | — |  |  | — |  |  | (893 | ) |  | (893 | ) |  | — |  |  | — |  |  | (893 | )
Amounts classified as marketable securities |  | $ | 196,120 |  | $ | 36 |  | $ | (19 | ) | $ | 196,137 |  | $ | 146,268 |  | $ | 49 |  | $ | (16 | ) | $ | 146,301 |
Schedule of net realized gains (losses) on marketable securities |
|  | Year Ended December 31, |
--- | --- | --- | ---
(in thousands) |  | 2011 |  | 2010 |  | 2009 |
Realized gains |  | $ | — |  | $ | 3 |  | $ | — |
Realized losses |  |  | (2 | ) |  | — |  |  | — |
Net realized gains (losses) |  | $ | (2 | ) | $ | 3 |  | $ | — |
Summary of marketable securities with unrealized losses |
|  | In loss position for less than 12 months |  | In loss position for more than 12 months |  | Total |
--- | --- | --- | --- | --- | --- | --- | ---
(in thousands) |  | Fair Value |  | Estimated Gross Unrealized Losses |  | Fair Value |  | Estimated Gross Unrealized Losses |  | Fair Value |  | Estimated Gross Unrealized Losses |
U.S. government agencies |  | $ | 47,807 |  | $ | (17 | ) | $ | — |  | $ | — |  | $ | 47,807 |  | $ | (17 | )
U.S. corporate notes |  |  | 2,754 |  |  | (2 | ) |  | — |  |  | — |  |  | 2,754 |  |  | (2 | )
Total |  | $ | 50,561 |  | $ | (19 | ) | $ | — |  | $ | — |  | $ | 50,561 |  | $ | (19 | )

X
- Details
Name: | us-gaap_MarketableSecuritiesAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of the reconciliation of available-for-sale securities from cost basis to fair value. + References No definition available. + Details
Name: | us-gaap_ScheduleOfAvailableForSaleSecuritiesReconciliationTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of the proceeds from sales of available-for-sale securities and the gross realized gains and gross realized losses that have been included in earnings as a result of those sales. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Topic 320 -SubTopic 10 -Publisher FASB -Number -Article -Subparagraph (a) -Name Accounting Standards Codification -Paragraph 9 -Section 50 -URI http://asc.fasb.org/extlink&oid=6872113&loc=d3e27357-111563 + Details
Name: | us-gaap_ScheduleOfRealizedGainLossTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition For all investments in an unrealized loss position, including those for which other-than-temporary impairments have not been recognized in earnings (including investments for which a portion of an other-than-temporary impairment has been recognized in other comprehensive income), a tabular disclosure of the aggregate related fair value of investments with unrealized losses and the aggregate amount of unrealized losses (that is, the amount by which amortized cost basis exceeds fair value). + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Topic 320 -SubTopic 10 -Publisher FASB -Number -Article -Subparagraph -Name Accounting Standards Codification -Paragraph 6 -Section 50 -URI http://asc.fasb.org/extlink&oid=6872113&loc=d3e27290-111563 + Details
Name: | us-gaap_ScheduleOfUnrealizedLossOnInvestmentsTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration