v2.4.0.8

Fair Value Measurements | 9 Months Ended | 12 Months Ended
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Sep. 30, 2013 | Dec. 31, 2012
Fair Value Disclosures [Abstract] |  |
Fair Value Measurements | 5. Fair Value Measurements The carrying amount of cash and cash equivalents, receivables, prepaid expenses and other current assets, accounts payable, accrued compensation and benefits, other accrued liabilities, and related party payables approximate fair value due to the short maturity of these instruments. The following table presents the placement in the fair value hierarchy of financial assets that are measured at fair value on a recurring basis, including the items for which the fair value option has been elected, at September 30, 2013:
|  | Quoted prices in active markets (level 1) |  |  | Significant other observable inputs (level 2) |  |  | Significant unobservable inputs (level 3) |  |  | September 30, 2013 |
Assets |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
U.S. government debt securities (Note 4) |  | $ | — |  |  | $ | 205,768 |  |  | $ | — |  |  | $ | 205,768 |
Commercial paper (Note 4) |  |  | — |  |  |  | 10,247 |  |  |  | — |  |  |  | 10,247 |
Certificates of deposit (Note 4) |  |  | — |  |  |  | 1,766 |  |  |  | — |  |  |  | 1,766 |
Equity securities (Note 3) |  |  | 75,754 |  |  |  | 31,813 |  |  |  | — |  |  |  | 107,567 |
|  | $ | 75,754 |  |  | $ | 249,594 |  |  | $ | — |  |  | $ | 325,348 |
The following table presents the placement in the fair value hierarchy of financial assets that are measured at fair value on a recurring basis, including the items for which the fair value option has been elected, at December 31, 2012:
|  | Quoted prices in active markets (level 1) |  |  | Significant other observable inputs (level 2) |  |  | Significant unobservable inputs (level 3) |  |  | December 31, 2012 |
Assets |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Certificates of deposit (Note 4) |  | $ | — |  |  | $ | 260 |  |  | $ | — |  |  | $ | 260 |
Equity securities (Note 3) |  |  | 72,988 |  |  |  | 10,128 |  |  |  | — |  |  |  | 83,116 |
|  | $ | 72,988 |  |  | $ | 10,388 |  |  | $ | — |  |  | $ | 83,376 |
There were no financial liabilities measured on a recurring basis at September 30, 2013 and December 31, 2012. The method used to estimate the fair value of the Level 1 assets in the tables above is based on observable market data as these equity securities are publicly-traded. The method used to estimate the fair value of the Level 2 short-term investments in the tables above is based on professional pricing sources for identical or comparable instruments, rather than direct observations of quote prices in active markets. The method used to estimate the fair value of the Level 2 equity securities in the tables above is based on the quoted market price of the publicly-traded security, adjusted for a discount for lack of marketability. There were no transfers between levels of the fair value hierarchy in the three and nine months ended September 30, 2013. | 5. Fair Value Measurements The carrying amount of cash and cash equivalents, short-term investments, receivables, prepaid expenses and other current assets, accounts payable, accrued compensation and benefits, other accrued liabilities, and related party payables approximate fair value due to the short maturity of these instruments. The following table presents the placement in the fair value hierarchy of financial assets that are measured at fair value on a recurring basis, including the items for which the fair value option has been elected, at December 31, 2012:
|  | Quoted prices in active markets (level 1) |  |  | Significant other observable inputs (level 2) |  |  | Significant unobservable inputs (level 3) |  |  | December 31, 2012 |
Assets |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Equity securities (Note 4) |  | $ | 72,988 |  |  | $ | 10,128 |  |  | $ | — |  |  | $ | 83,116 |
|  | $ | 72,988 |  |  | $ | 10,128 |  |  | $ | — |  |  | $ | 83,116 |
The following table presents the placement in the fair value hierarchy of financial assets that are measured at fair value on a recurring basis, including the items for which the fair value option has been elected, at December 31, 2011:
|  | Quoted prices in active markets (level 1) |  |  | Significant other observable inputs (level 2) |  |  | Significant unobservable inputs (level 3) |  |  | December 31, 2011 |
Assets |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Equity securities (Note 4) |  | $ | 39,097 |  |  | $ | — |  |  | $ | — |  |  | $ | 39,097 |
|  | $ | 39,097 |  |  | $ | — |  |  | $ | — |  |  | $ | 39,097 |
There were no financial liabilities measured on a recurring basis at December 31, 2012 and 2011. The method used to estimate the fair value of the Level 1 assets in the tables above is based on observable market data as these equity securities are publicly-traded. The method used to estimate the fair value of the Level 2 assets in the tables above is based on the quoted market price of the publicly-traded security, adjusted for a discount for lack of marketability. There were no transfers between levels of the fair value hierarchy in the years ended December 31, 2012 and 2011.

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- Definition The entire disclosure for the fair value of financial instruments (as defined), including financial assets and financial liabilities (collectively, as defined), and the measurements of those instruments as well as disclosures related to the fair value of non-financial assets and liabilities. Such disclosures about the financial instruments, assets, and liabilities would include: (1) the fair value of the required items together with their carrying amounts (as appropriate); (2) for items for which it is not practicable to estimate fair value, disclosure would include: (a) information pertinent to estimating fair value (including, carrying amount, effective interest rate, and maturity, and (b) the reasons why it is not practicable to estimate fair value; (3) significant concentrations of credit risk including: (a) information about the activity, region, or economic characteristics identifying a concentration, (b) the maximum amount of loss the entity is exposed to based on the gross fair value of the related item, (c) policy for requiring collateral or other security and information as to accessing such collateral or security, and (d) the nature and brief description of such collateral or security; (4) quantitative information about market risks and how such risks are managed; (5) for items measured on both a recurring and nonrecurring basis information regarding the inputs used to develop the fair value measurement; and (6) for items presented in the financial statement for which fair value measurement is elected: (a) information necessary to understand the reasons for the election, (b) discussion of the effect of fair value changes on earnings, (c) a description of [similar groups] items for which the election is made and the relation thereof to the balance sheet, the aggregate carrying value of items included in the balance sheet that are not eligible for the election; (7) all other required (as defined) and desired information. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 50 -Paragraph 21 -URI http://asc.fasb.org/extlink&oid=28364263&loc=d3e13537-108611 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 50 -Paragraph 10 -URI http://asc.fasb.org/extlink&oid=28364263&loc=d3e13433-108611 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 50 -Paragraph 28 -URI http://asc.fasb.org/extlink&oid=6957238&loc=d3e14064-108612 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=25499696&loc=d3e19207-110258 Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 50 -Paragraph 30 -URI http://asc.fasb.org/extlink&oid=6957238&loc=d3e14172-108612 Reference 6: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 50 -Paragraph 16 -URI http://asc.fasb.org/extlink&oid=28364263&loc=d3e13504-108611 + Details
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