v2.4.0.8

Short-term and Long-term Investments (Tables) | 9 Months Ended
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Sep. 30, 2013
Investments Debt And Equity Securities [Abstract] |
Summary of Amortized Cost, Gross Unrealized Gains and Losses and Fair Value of Investments | The following table summarizes the amortized cost, gross unrealized gains and losses and fair value of available-for-sale investments as of September 30, 2013:
|  | Amortized Cost |  |  | Gross Unrealized Gains |  |  | Gross Unrealized Losses |  |  | Aggregate Fair Value |
U.S. government debt securities |  | $ | 205,747 |  |  | $ | 27 |  |  | $ | (6 | ) |  | $ | 205,768 |
Commercial paper |  |  | 10,242 |  |  |  | 6 |  |  |  | (1 | ) |  |  | 10,247 |
Certificates of deposit |  |  | 1,768 |  |  |  | — |  |  |  | (2 | ) |  |  | 1,766 |
Total |  | $ | 217,757 |  |  | $ | 33 |  |  | $ | (9 | ) |  | $ | 217,781 |
Summary of Estimated Fair Value of Available-for-Sale Investments Classified by Contractual Maturities | The estimated fair value of available-for-sale investments classified by their contractual maturities as of September 30, 2013 was as follows:
Due within one year |  | $ | 136,672 |
After one year through two years |  |  | 81,109 |
Total |  | $ | 217,781 |

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- Definition Tabular disclosure of available-for-sale securities which includes, but is not limited to, changes in the cost basis and fair value, fair value and gross unrealized gain (loss), fair values by type of security, contractual maturity and classification, amortized cost basis, contracts to acquire securities to be accounted for as available-for-sale, debt maturities, transfers to trading, change in net unrealized holding gain (loss) net of tax, continuous unrealized loss position fair value, aggregate losses qualitative disclosures, other than temporary impairment (OTTI) losses or other disclosures related to available for sale securities. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 6 -URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27290-111563 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 9 -URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27357-111563 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 7 -URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27337-111563 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 320 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=6957658&loc=d3e62557-112803 Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27198-111563 Reference 6: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 320 -Section 50 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=6957658&loc=d3e62586-112803 Reference 7: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27161-111563 + Details
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