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Background and Significant Accounting Policies (Details2) In Thousands, unless otherwise specified | 12 Months Ended
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Dec. 31, 2011 | Dec. 31, 2010 | Dec. 31, 2009
Anti-dilutive effect of the calculation of net dilutive potential shares of common stock issuable |  |  |
Net dilutive potential common shares issuable | 24,487 | 23,364 | 15,189
On exercise of options where exercise price is greater than average market value for the period [Member] |  |  |
Anti-dilutive effect of the calculation of net dilutive potential shares of common stock issuable |  |  |
Net dilutive potential common shares issuable | 2,533 | 1,359 | 1,140
On exercise of options and vesting of restricted stock and restricted stock units [Member] |  |  |
Anti-dilutive effect of the calculation of net dilutive potential shares of common stock issuable |  |  |
Net dilutive potential common shares issuable | 675 | 735 | 539
On settlement of employee stock purchase plan shares [Member] |  |  |
Anti-dilutive effect of the calculation of net dilutive potential shares of common stock issuable |  |  |
Net dilutive potential common shares issuable | 23 | 14 | 30
On exercise of warrants [Member] |  |  |
Anti-dilutive effect of the calculation of net dilutive potential shares of common stock issuable |  |  |
Net dilutive potential common shares issuable | 2,808 | 2,808 | 1,604
On conversion of 4.25% convertible senior notes due 2014 [Member] |  |  |
Anti-dilutive effect of the calculation of net dilutive potential shares of common stock issuable |  |  |
Net dilutive potential common shares issuable | 15,334 | 15,334 | 8,762
On conversion of 4.75% convertible senior notes due 2014 [Member] |  |  |
Anti-dilutive effect of the calculation of net dilutive potential shares of common stock issuable |  |  |
Net dilutive potential common shares issuable | 3,114 | 3,114 | 3,114

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- Definition Securities (including those issuable pursuant to contingent stock agreements) that could potentially dilute basic earnings per share (EPS) or earnings per unit (EPU) in the future that were not included in the computation of diluted EPS or EPU because to do so would increase EPS or EPU amounts or decrease loss per share or unit amounts for the period presented. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Antidilution -URI http://asc.fasb.org/extlink&oid=6505113 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 128 -Paragraph 171 -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 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 128 -Paragraph 40 -Subparagraph c -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 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 128 -Paragraph 13, 14 -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 5: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Emerging Issues Task Force (EITF) -Number 07-4 -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 6: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Diluted Earnings Per Share -URI http://asc.fasb.org/extlink&oid=6510752 Reference 7: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 260 -SubTopic 10 -Section 50 -Paragraph 1 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=6371337&loc=d3e3550-109257 Reference 8: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Contingent Stock Agreement -URI http://asc.fasb.org/extlink&oid=6508534 + Details
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