2.4.0.8133 - Disclosure - Fair Value of Derivative Financial Instruments (Tables)truefalsefalse1false falsefalseeol_PE10315---13S-1-0008_STD_366_20121231_0http://www.sec.gov/CIK0001069308duration2012-01-01T00:00:002012-12-31T00:00:001false 4us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationTextBlockus-gaap_truenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00<div> The following table provides a summary of the changes in fair value, including net transfers in and/or out, of the derivative financial instruments, measured at fair value on a recurring basis using significant unobservable inputs (Level 3):   <table style="BORDER-COLLAPSE: collapse" border="0" cellspacing="0" cellpadding="0" width="68%" align="center"> <tr> <td width="84%"></td> <td valign="bottom" width="13%"></td> <td></td> <td></td> <td></td> </tr> <tr bgcolor="#CCEEFF"> <td valign="top"> Balance at December 31, 2011 </td> <td valign="bottom">  </td> <td valign="bottom">$</td> <td valign="bottom" align="right">—  </td> <td valign="bottom" nowrap="nowrap">  </td> </tr> <tr> <td valign="top"> Fair value of warrant derivative liabilities at issuance </td> <td valign="bottom">  </td> <td valign="bottom"> </td> <td valign="bottom" align="right">2,314,635</td> <td valign="bottom" nowrap="nowrap">  </td> </tr> <tr bgcolor="#CCEEFF"> <td valign="top"> Realized derivative gains included in other income (expense) </td> <td valign="bottom">  </td> <td valign="bottom"> </td> <td valign="bottom" align="right">(552,978</td> <td valign="bottom" nowrap="nowrap">) </td> </tr> <tr> <td valign="top"> Write off of warrant derivative liability to additional paid in capital </td> <td valign="bottom">  </td> <td valign="bottom"> </td> <td valign="bottom" align="right">(1,761,657</td> <td valign="bottom" nowrap="nowrap">) </td> </tr> <tr style="FONT-SIZE: 1px"> <td valign="bottom"></td> <td valign="bottom">  </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> </tr> <tr bgcolor="#CCEEFF"> <td valign="top"> Balance at December 31, 2012 </td> <td valign="bottom">  </td> <td valign="bottom">$</td> <td valign="bottom" align="right">—  </td> <td valign="bottom" nowrap="nowrap">  </td> </tr> <tr style="FONT-SIZE: 1px"> <td valign="bottom"></td> <td valign="bottom">  </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> </tr> </table> </div>falsefalsefalsenonnum:textBlockItemTypenaTabular disclosure of the fair value measurement of liabilities using significant unobservable inputs (Level 3), a reconciliation of the beginning and ending balances, separately presenting changes attributable to the following: (1) total gains or losses for the period (realized and unrealized), segregating those gains or losses included in earnings (or changes in net assets), and gains or losses recognized in other comprehensive income (loss) and a description of where those gains or losses included in earnings (or changes in net assets) are reported in the statement of income (or activities); (2) purchases, sales, issues, and settlements (each type disclosed separately); and (3) transfers in and transfers out of Level 3 (for example, transfers due to changes in the observability of significant inputs) by class of liability.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=25499696&loc=d3e19279-110258 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=25499696&loc=d3e19207-110258 false0Changes in Fair Value of Derivative Financial Instruments Measured at Fair Value on Recurring Basis using Significant Unobservable Inputs2false 4opxa_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsMethodUsedTableTextBlockopxa_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00<div> The variables used in the Lattice option pricing model for the derivative liabilities during the year ended December 31, 2012 include:   <table style="BORDER-COLLAPSE: collapse" border="0" cellspacing="0" cellpadding="0" width="84%" align="center">  <tr> <td width="46%"></td> <td valign="bottom" width="7%"></td> <td></td> <td></td> <td></td> <td valign="bottom" width="7%"></td> <td></td> <td></td> <td></td> <td valign="bottom" width="7%"></td> <td></td> <td></td> <td></td> </tr> <tr> <td valign="bottom"></td> <td valign="bottom"></td> <td style="BORDER-BOTTOM: #000000 1px solid" valign="bottom" colspan="2" align="center">July 25, 2012</td> <td valign="bottom"></td> <td valign="bottom"></td> <td style="BORDER-BOTTOM: #000000 1px solid" valign="bottom" colspan="2" align="center">September 30, 2012</td> <td valign="bottom"></td> <td valign="bottom"></td> <td style="BORDER-BOTTOM: #000000 1px solid" valign="bottom" colspan="2" align="center">November 8, 2012</td> <td valign="bottom"></td> </tr>  <tr bgcolor="#CCEEFF"> <td valign="top"> Market value of common stock on measurement date </td> <td valign="bottom"></td> <td valign="bottom">$</td> <td valign="bottom" align="right">2.56</td> <td valign="bottom" nowrap="nowrap"></td> <td valign="bottom"></td> <td valign="bottom">$</td> <td valign="bottom" align="right">2.70</td> <td valign="bottom" nowrap="nowrap"></td> <td valign="bottom"></td> <td valign="bottom">$</td> <td valign="bottom" align="right">1.96</td> <td valign="bottom" nowrap="nowrap"></td> </tr> <tr> <td valign="top"> Projected exercise price </td> <td valign="bottom"></td> <td valign="bottom">$</td> <td valign="bottom" align="right">5.00</td> <td valign="bottom" nowrap="nowrap"></td> <td valign="bottom"></td> <td valign="bottom">$</td> <td valign="bottom" align="right">4.52</td> <td valign="bottom" nowrap="nowrap"></td> <td valign="bottom"></td> <td valign="bottom">$</td> <td valign="bottom" align="right">4.56</td> <td valign="bottom" nowrap="nowrap"></td> </tr> <tr bgcolor="#CCEEFF"> <td valign="top"> Risk free interest rate </td> <td valign="bottom"></td> <td valign="bottom"></td> <td valign="bottom" align="right">0.56%</td> <td valign="bottom" nowrap="nowrap"></td> <td valign="bottom"></td> <td valign="bottom"></td> <td valign="bottom" align="right">0.56%</td> <td valign="bottom" nowrap="nowrap"></td> <td valign="bottom"></td> <td valign="bottom"></td> <td valign="bottom" align="right">0.72%</td> <td valign="bottom" nowrap="nowrap"></td> </tr> <tr> <td valign="top"> Warrant lives in years </td> <td valign="bottom"></td> <td valign="bottom"></td> <td valign="bottom" align="right">5</td> <td valign="bottom" nowrap="nowrap"></td> <td valign="bottom"></td> <td valign="bottom"></td> <td valign="bottom" align="right">4.88</td> <td valign="bottom" nowrap="nowrap"></td> <td valign="bottom"></td> <td valign="bottom"></td> <td valign="bottom" align="right">4.71</td> <td valign="bottom" nowrap="nowrap"></td> </tr> <tr bgcolor="#CCEEFF"> <td valign="top"> Expected volatility </td> <td valign="bottom"></td> <td valign="bottom"></td> <td valign="bottom" align="right">193%</td> <td valign="bottom" nowrap="nowrap"></td> <td valign="bottom"></td> <td valign="bottom"></td> <td valign="bottom" align="right">193%</td> <td valign="bottom" nowrap="nowrap"></td> <td valign="bottom"></td> <td valign="bottom"></td> <td valign="bottom" align="right">194%</td> <td valign="bottom" nowrap="nowrap"></td> </tr> <tr> <td valign="top"> Expected dividend yield </td> <td valign="bottom"></td> <td valign="bottom"></td> <td valign="bottom" align="right">0%</td> <td valign="bottom" nowrap="nowrap"></td> <td valign="bottom"></td> <td valign="bottom"></td> <td valign="bottom" align="right">0%</td> <td valign="bottom" nowrap="nowrap"></td> <td valign="bottom"></td> <td valign="bottom"></td> <td valign="bottom" align="right">0%</td> <td valign="bottom" nowrap="nowrap"></td> </tr> <tr bgcolor="#CCEEFF"> <td valign="top"> Offering price range </td> <td valign="bottom"></td> <td valign="bottom">$</td> <td valign="bottom" align="right">2.56-$6.56</td> <td valign="bottom" nowrap="nowrap"></td> <td valign="bottom"></td> <td valign="bottom">$</td> <td valign="bottom" align="right">2.72-$6.72</td> <td valign="bottom" nowrap="nowrap"></td> <td valign="bottom"></td> <td valign="bottom">$</td> <td valign="bottom" align="right">2.56-$6.56</td> <td valign="bottom" nowrap="nowrap"></td> </tr> </table> </div>falsefalsefalsenonnum:textBlockItemTypenaShare Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Method Used.No definition available.false0Variables used in Lattice Option Pricing Model for Derivative LiabilitiesfalseFair Value of Derivative Financial Instruments (Tables)UnKnownUnKnownUnKnownUnKnowntruefalsefalseSheethttp://www.opexatherapeutics.com/taxonomy/role/NotesToFinancialStatementsFairValueDisclosuresTextBlockTables12