2.4.0.8100170 - Disclosure - Summary of Significant Accounting Policies (Policies)truefalsefalse1false falsefalseC_0001269021_20130101_20130630http://www.sec.gov/CIK0001269021duration2013-01-01T00:00:002013-06-30T00:00:001false 4us-gaap_ConsolidationPolicyTextBlockus-gaap_truenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00<div> Basis of Presentation The accompanying unaudited condensed financial statements have been prepared in accordance with U.S. generally accepted accounting principles (“U.S. GAAP”), and following the requirements of the Securities and Exchange Commission (“SEC”) for interim reporting. As permitted under those rules, certain footnotes or other financial information that are normally required by U.S. GAAP can be condensed or omitted. These financial statements have been prepared on the same basis as the Company’s annual financial statements and, in the opinion of management, reflect all adjustments, consisting only of normal recurring adjustments, that are necessary for a fair statement of the Company’s financial information. The results of operations for the six months ended June 30, 2013 are not necessarily indicative of the results to be expected for the year ending December 31, 2013. The condensed balance sheet as of December 31, 2012 has been derived from audited financial statements at that date but does not include all of the information required by U.S. GAAP for complete financial statements. The accompanying condensed financial statements and related financial information should be read in conjunction with the audited financial statements and the related notes thereto for the year ended December 31, 2012 included in the Company’s Prospectus filed pursuant to Rule 424(b)(4) as filed on May 21, 2013 with the SEC. </div>falsefalsefalsenonnum:textBlockItemTypenaDisclosure of accounting policy regarding (1) the principles it follows in consolidating or combining the separate financial statements, including the principles followed in determining the inclusion or exclusion of subsidiaries or other entities in the consolidated or combined financial statements and (2) its treatment of interests (for example, common stock, a partnership interest or other means of exerting influence) in other entities, for example consolidation or use of the equity or cost methods of accounting. The accounting policy may also address the accounting treatment for intercompany accounts and transactions, noncontrolling interest, and the income statement treatment in consolidation for issuances of stock by a subsidiary.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Emerging Issues Task Force (EITF) -Number 97-2 -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 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name FASB Interpretation (FIN) -Number 46R -Paragraph 4 -Subparagraph c -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. 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Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 140 -Paragraph 46 -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 FASB Interpretation (FIN) -Number 46R -Paragraph 4 -Subparagraph d -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 7: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02, 03 -Article 3A Reference 8: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Emerging Issues Task Force (EITF) -Number 96-16 -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 9: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Principles Board Opinion (APB) -Number 18 -Paragraph 20 -Subparagraph a(2) -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 10: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name FASB Interpretation (FIN) -Number 46R -Paragraph 14, 15 -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 11: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section 50 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=6367646&loc=d3e18780-107790 Reference 12: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 810 -SubTopic 10 -URI http://asc.fasb.org/subtopic&trid=2197480 Reference 13: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 810 -SubTopic 10 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=18733093&loc=d3e5614-111684 Reference 14: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 810 -SubTopic 10 -Section S99 -Paragraph 2 -Subparagraph (SX 210.3A-02) -URI http://asc.fasb.org/extlink&oid=6959686&loc=d3e355033-122828 Reference 15: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 51 -Paragraph 2-6 -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 16: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 860 -SubTopic 40 -Section 45 -URI http://asc.fasb.org/section&trid=2197723 Reference 17: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 323 -SubTopic 10 -URI http://asc.fasb.org/subtopic&trid=2196966 Reference 18: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 325 -SubTopic 20 -URI http://asc.fasb.org/subtopic&trid=2197087 Reference 19: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 323 -SubTopic 10 -Section 45 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=16385135&loc=d3e33801-111570 false0Bases of Presentation2false 4ptla_ReverseStockSplitPolicyTextBlockptla_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00<div> Reverse Stock Split On May 17, 2013, the Company effected a 1-for-10 reverse split of our preferred stock and common stock. Upon the effectiveness of the reverse stock split every 10 shares of outstanding preferred stock and common stock was decreased to one share of preferred stock or common stock, as applicable, the number of shares of common stock into which each outstanding option to purchase common stock is exercisable was proportionately decreased on a 1-for-10 basis, and the exercise price of each outstanding option to purchase common stock was proportionately increased on a 1-for-10 basis. All the shares numbers, share prices and exercise prices have been adjusted within the condensed financial statements, on a retroactive basis, to reflect the 1-for-10 reverse stock split. </div>falsefalsefalsenonnum:textBlockItemTypenaReverse stock split.No definition available.false0Reverse Stock Split3false 4ptla_AdditionalCapitalRequirementsPolicyTextBlockptla_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00<div> Additional Capital Requirements We have incurred significant losses and negative cash flows from operations. As of June 30, 2013, we had an accumulated deficit of $242.4 million and cash, cash equivalents and investments of $235.2 million. Our management believes that currently available resources will provide sufficient funds to enable us to meet our obligations for at least the next twelve months based on our current business plans. However, if our anticipated operating results are not achieved in future periods, our management believes that planned expenditures may need to be reduced in order to extend the time period over which the then-available resources would be able to fund our operations. We will need to raise additional capital to fully implement our business plan. </div>falsefalsefalsenonnum:textBlockItemTypenaAdditional capital requirements.No definition available.false0Additional Capital Requirements4false 4us-gaap_UseOfEstimatesus-gaap_truenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00<div> Use of Estimates The preparation of condensed financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, disclosure of contingent assets and liabilities and the reported amounts of revenues and expenses in the condensed financial statements and the accompanying notes. On an ongoing basis, management evaluates its estimates, including those related to revenue recognition, clinical trial accruals, fair value of assets and liabilities, income taxes and stock-based compensation. Management bases its estimates on historical experience and on various other market-specific and relevant assumptions that management believes to be reasonable under the circumstances. Actual results may differ from those estimates. </div>falsefalsefalsenonnum:textBlockItemTypenaDisclosure of accounting policy for the use of estimates in the preparation of financial statements in conformity with generally accepted accounting principles.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 275 -SubTopic 10 -Section 50 -Paragraph 9 -URI http://asc.fasb.org/extlink&oid=6927468&loc=d3e6143-108592 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 275 -SubTopic 10 -Section 50 -Paragraph 8 -URI http://asc.fasb.org/extlink&oid=6927468&loc=d3e6132-108592 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 275 -SubTopic 10 -Section 50 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=6927468&loc=d3e6061-108592 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Statement of Position (SOP) -Number 94-6 -Paragraph 11, 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. false0Use of Estimates5false 4us-gaap_CashAndCashEquivalentsPolicyTextBlockus-gaap_truenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00<div> Cash and Cash Equivalents Cash and cash equivalents consist of cash and other highly liquid investments with original maturities of three months or less from the date of purchase. </div>falsefalsefalsenonnum:textBlockItemTypenaDisclosure of accounting policy for cash and cash equivalents, including the policy for determining which items are treated as cash equivalents. Other information that may be disclosed includes (1) the nature of any restrictions on the entity's use of its cash and cash equivalents, (2) whether the entity's cash and cash equivalents are insured or expose the entity to credit risk, (3) the classification of any negative balance accounts (overdrafts), and (4) the carrying basis of cash equivalents (for example, at cost) and whether the carrying amount of cash equivalents approximates fair value.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section 50 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=6367646&loc=d3e18780-107790 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Cash -URI http://asc.fasb.org/extlink&oid=6506951 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Cash Equivalents -URI http://asc.fasb.org/extlink&oid=6507016 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6367179&loc=d3e4273-108586 Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 1 -Article 5 Reference 6: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 305 -SubTopic 10 -URI http://asc.fasb.org/subtopic&trid=2122427 Reference 7: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Financial Reporting Release (FRR) -Number 203 -Paragraph 02-03 Reference 8: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Technical Practice Aid (TPA) -Number 2110 -Paragraph 6 -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 9: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 7, 8, 9, 10 -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. false0Cash and Cash Equivalents6false 4us-gaap_InvestmentPolicyTextBlockus-gaap_truenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00<div> Investments All investments have been classified as “available-for-sale” and are carried at estimated fair value as determined based upon quoted market prices or pricing models for similar securities. Management determines the appropriate classification of its investments in debt securities at the time of purchase and reevaluates such designation as of each balance sheet date. Unrealized gains and losses are excluded from earnings and were reported as a component of accumulated comprehensive income. Realized gains and losses and declines in fair value judged to be other than temporary, if any, on available-for-sale securities are included in interest and other income (expense), net. The cost of securities sold is based on the specific-identification method. Interest on marketable securities is included in interest and other income (expense), net. </div>falsefalsefalsenonnum:textBlockItemTypenaDisclosure of accounting policy for investments in financial assets, including marketable securities (debt and equity securities with readily determinable fair values), investments accounted for under the equity method and cost method, securities borrowed and loaned, and repurchase and resale agreements. For marketable securities, the disclosure may include the entity's accounting treatment for transfers between investment categories and how the fair values for such securities are determined. Also, for all investments, an entity may describe its policy for assessing, recognizing and measuring impairment of the investment.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 115 -Paragraph 7-16 -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 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 107 -Paragraph 10, 11 -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 Accounting Standards Codification -Topic 235 -SubTopic 10 -Section 50 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=6367646&loc=d3e18780-107790 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 325 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=6872867&loc=d3e40691-111596 Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 50 -Paragraph 10 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=7491637&loc=d3e13433-108611 Reference 6: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 323 -SubTopic 10 -Section 50 -Paragraph 3 -Subparagraph (a)(2) -URI http://asc.fasb.org/extlink&oid=6382943&loc=d3e33918-111571 Reference 7: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 6 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=6872113&loc=d3e27290-111563 Reference 8: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Staff Accounting Bulletin (SAB) -Number Topic 5 -Section M Reference 9: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.2,12) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 10: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name FASB Staff Position (FSP) -Number FAS115-1/124-1 -Paragraph 7-18 -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 11: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 2, 12 -Article 5 false0Investments7false 4us-gaap_ConcentrationRiskCreditRiskus-gaap_truenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00<div> Customer Concentration Customers whose collaborative research and development revenue accounted for 10% or more of total revenues were as follows:   <div style="text-align: left;"> <table cellspacing="0" cellpadding="0" style="display: block; text-align: left; border: 0"> <tr> <th style="padding-right:0.7pt; padding-top:0.7pt; vertical-align:bottom">   </th> <th colspan="7" style="padding-right:0.7pt; padding-top:0.7pt; vertical-align:bottom"> Three Months Ended June 30, </th> <th style="padding-right:0.7pt; padding-top:0.7pt; vertical-align:bottom" colspan="2">   </th> <th style="padding-right:0.7pt; padding-top:0.7pt; vertical-align:bottom">   </th> <th colspan="9" style="padding-right:0.7pt; padding-top:0.7pt; vertical-align:bottom"> Six Months Ended June 30, </th> <th style="padding-right:0.7pt; padding-top:0.7pt; vertical-align:bottom">   </th> </tr> <tr> <th style="padding-right:0.7pt; padding-top:0.7pt; vertical-align:bottom">   </th> <th style="border-bottom-color:#000000; border-bottom-style:solid; border-bottom-width:0.5pt; padding-right:0.7pt; padding-top:0.7pt; vertical-align:bottom">   </th> <th style="border-bottom-color:#000000; border-bottom-style:solid; border-bottom-width:0.5pt; padding-right:0.7pt; padding-top:0.7pt; vertical-align:bottom"> 2013 </th> <th style="padding-right:0.7pt; padding-top:0.7pt; vertical-align:bottom" colspan="2">   </th> <th style="padding-right:0.7pt; padding-top:0.7pt; vertical-align:bottom">   </th> <th style="border-bottom-color:#000000; border-bottom-style:solid; border-bottom-width:0.5pt; padding-right:0.7pt; padding-top:0.7pt; vertical-align:bottom">   </th> <th style="border-bottom-color:#000000; border-bottom-style:solid; border-bottom-width:0.5pt; padding-right:0.7pt; padding-top:0.7pt; vertical-align:bottom"> 2012 </th> <th style="padding-right:0.7pt; padding-top:0.7pt; vertical-align:bottom" colspan="2">   </th> <th style="padding-right:0.7pt; padding-top:0.7pt; vertical-align:bottom">   </th> <th style="border-bottom-color:#000000; border-bottom-style:solid; border-bottom-width:0.5pt; padding-right:0.7pt; padding-top:0.7pt; vertical-align:bottom">   </th> <th style="border-bottom-color:#000000; border-bottom-style:solid; border-bottom-width:0.5pt; padding-right:0.7pt; padding-top:0.7pt; vertical-align:bottom"> 2013 </th> <th style="padding-right:0.7pt; padding-top:0.7pt; vertical-align:bottom" colspan="2">   </th> <th style="padding-right:0.7pt; padding-top:0.7pt; vertical-align:bottom">   </th> <th style="border-bottom-color:#000000; border-bottom-style:solid; border-bottom-width:0.5pt; padding-right:0.7pt; padding-top:0.7pt; vertical-align:bottom">   </th> <th style="border-bottom-color:#000000; border-bottom-style:solid; border-bottom-width:0.5pt; padding-right:0.7pt; padding-top:0.7pt; vertical-align:bottom"> 2012 </th> <th colspan="3" style="padding-right:0.7pt; padding-top:0.7pt; vertical-align:bottom">   </th> </tr> <tr> <td style="background-color:#cff0fc; padding-right:0.7pt; padding-top:0.7pt; vertical-align:bottom"> Novartis AG              </td> <td style="background-color:#cff0fc; border-top-color:#000000; border-top-style:solid; border-top-width:0.5pt; padding-right:0.7pt; padding-top:0.7pt; vertical-align:bottom">   </td> <td style="background-color:#cff0fc; border-top-color:#000000; border-top-style:solid; border-top-width:0.5pt; padding-right:0.7pt; padding-top:0.7pt; vertical-align:bottom; text-align:right">—</td> <td style="background-color:#cff0fc; padding-right:0.7pt; padding-top:0.7pt; vertical-align:bottom" colspan="2">   </td> <td style="background-color:#cff0fc; padding-right:0.7pt; padding-top:0.7pt; vertical-align:bottom">   </td> <td style="background-color:#cff0fc; border-top-color:#000000; border-top-style:solid; border-top-width:0.5pt; padding-right:0.7pt; padding-top:0.7pt; vertical-align:bottom">   </td> <td style="background-color:#cff0fc; border-top-color:#000000; border-top-style:solid; border-top-width:0.5pt; padding-right:0.7pt; padding-top:0.7pt; vertical-align:bottom; text-align:right">  100</td> <td style="background-color:#cff0fc; padding-top:0.7pt; vertical-align:bottom; text-align:right"></td><td style="background-color:#cff0fc; padding-right:0.7pt; padding-top:0.7pt; vertical-align:bottom; text-align:left">%</td> <td style="background-color:#cff0fc; padding-right:0.7pt; padding-top:0.7pt; vertical-align:bottom">   </td> <td style="background-color:#cff0fc; border-top-color:#000000; border-top-style:solid; border-top-width:0.5pt; padding-right:0.7pt; padding-top:0.7pt; vertical-align:bottom">   </td> <td style="background-color:#cff0fc; border-top-color:#000000; border-top-style:solid; border-top-width:0.5pt; padding-right:0.7pt; padding-top:0.7pt; vertical-align:bottom; text-align:right">—</td> <td style="background-color:#cff0fc; padding-right:0.7pt; padding-top:0.7pt; vertical-align:bottom" colspan="2">   </td> <td style="background-color:#cff0fc; padding-right:0.7pt; padding-top:0.7pt; vertical-align:bottom">   </td> <td style="background-color:#cff0fc; border-top-color:#000000; border-top-style:solid; border-top-width:0.5pt; padding-right:0.7pt; padding-top:0.7pt; vertical-align:bottom">   </td> <td style="background-color:#cff0fc; border-top-color:#000000; border-top-style:solid; border-top-width:0.5pt; padding-right:0.7pt; padding-top:0.7pt; vertical-align:bottom; text-align:right">  100</td> <td style="background-color:#cff0fc; padding-top:0.7pt; vertical-align:bottom; text-align:right"></td><td style="background-color:#cff0fc; padding-right:0.7pt; padding-top:0.7pt; vertical-align:bottom; text-align:left" colspan="2">%</td> </tr> <tr> <td style="padding-right:0.7pt; padding-top:0.7pt; vertical-align:bottom"> Bristol-Myers Squibb Company and Pfizer Inc.              </td> <td style="padding-right:0.7pt; padding-top:0.7pt; vertical-align:bottom">   </td> <td style="padding-right:0.7pt; padding-top:0.7pt; vertical-align:bottom; text-align:right">  43</td> <td style="padding-top:0.7pt; vertical-align:bottom; text-align:right"></td><td style="padding-right:0.7pt; padding-top:0.7pt; vertical-align:bottom; text-align:left">%</td> <td style="padding-right:0.7pt; padding-top:0.7pt; vertical-align:bottom">   </td> <td style="padding-right:0.7pt; padding-top:0.7pt; vertical-align:bottom">   </td> <td style="padding-right:0.7pt; padding-top:0.7pt; vertical-align:bottom; text-align:right">—</td> <td style="padding-right:0.7pt; padding-top:0.7pt; vertical-align:bottom" colspan="2">   </td> <td style="padding-right:0.7pt; padding-top:0.7pt; vertical-align:bottom">   </td> <td style="padding-right:0.7pt; padding-top:0.7pt; vertical-align:bottom">   </td> <td style="padding-right:0.7pt; padding-top:0.7pt; vertical-align:bottom; text-align:right">  54</td> <td style="padding-top:0.7pt; vertical-align:bottom; text-align:right"></td><td style="padding-right:0.7pt; padding-top:0.7pt; vertical-align:bottom; text-align:left">%</td> <td style="padding-right:0.7pt; padding-top:0.7pt; vertical-align:bottom">   </td> <td style="padding-right:0.7pt; padding-top:0.7pt; vertical-align:bottom">   </td> <td style="padding-right:0.7pt; padding-top:0.7pt; vertical-align:bottom; text-align:right">—</td> <td colspan="3" style="padding-right:0.7pt; padding-top:0.7pt; vertical-align:bottom">   </td> </tr> <tr> <td style="background-color:#cff0fc; padding-right:0.7pt; padding-top:0.7pt; vertical-align:bottom"> Bayer Pharma, AG and Janssen Pharmaceuticals, Inc.              </td> <td style="background-color:#cff0fc; padding-right:0.7pt; padding-top:0.7pt; vertical-align:bottom">   </td> <td style="background-color:#cff0fc; padding-right:0.7pt; padding-top:0.7pt; vertical-align:bottom; text-align:right">  51</td> <td style="background-color:#cff0fc; padding-top:0.7pt; vertical-align:bottom; text-align:right"></td><td style="background-color:#cff0fc; padding-right:0.7pt; padding-top:0.7pt; vertical-align:bottom; text-align:left">%</td> <td style="background-color:#cff0fc; padding-right:0.7pt; padding-top:0.7pt; vertical-align:bottom">   </td> <td style="background-color:#cff0fc; padding-right:0.7pt; padding-top:0.7pt; vertical-align:bottom">   </td> <td style="background-color:#cff0fc; padding-right:0.7pt; padding-top:0.7pt; vertical-align:bottom; text-align:right">—</td> <td style="background-color:#cff0fc; padding-right:0.7pt; padding-top:0.7pt; vertical-align:bottom" colspan="2">   </td> <td style="background-color:#cff0fc; padding-right:0.7pt; padding-top:0.7pt; vertical-align:bottom">   </td> <td style="background-color:#cff0fc; padding-right:0.7pt; padding-top:0.7pt; vertical-align:bottom">   </td> <td style="background-color:#cff0fc; padding-right:0.7pt; padding-top:0.7pt; vertical-align:bottom; text-align:right">  43</td> <td style="background-color:#cff0fc; padding-top:0.7pt; vertical-align:bottom; text-align:right"></td><td style="background-color:#cff0fc; 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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 107 -Paragraph 15A -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 113 -Paragraph 28 -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 Accounting Standards Codification -Topic 944 -SubTopic 825 -Section 55 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6487554&loc=d3e32600-158583 Reference 6: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 50 -Paragraph 20 -URI http://asc.fasb.org/extlink&oid=7491637&loc=d3e13531-108611 Reference 7: 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=7491637&loc=d3e13537-108611 Reference 8: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 825 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=6480020&loc=d3e61082-112788 Reference 9: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 825 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6480020&loc=d3e61044-112788 Reference 10: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Statement of Position (SOP) -Number 01-6 -Paragraph 14 -Subparagraph m -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 11: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 55 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6875567&loc=d3e14489-108613 false0Customer Concentration8false 4us-gaap_DeferredChargesPolicyTextBlockus-gaap_truenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00<div> Deferred Offering Costs Deferred offering costs, which primarily consist of direct incremental legal, accounting and printing fees incurred in the preparation of the IPO, were capitalized. The deferred offering costs were offset against IPO proceeds upon completion of the offering in May 2013. As of December 31, 2012, $1.6 million of deferred offering costs were capitalized in other assets on the balance sheets. There were no remaining amounts deferred at June 30, 2013. </div>falsefalsefalsenonnum:textBlockItemTypenaDisclosure of accounting policy for deferral and amortization of significant deferred charges.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section 50 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=6367646&loc=d3e18780-107790 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.17) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 17 -Article 5 false0Deferred Offering Costs9false 4us-gaap_RevenueRecognitionPolicyTextBlockus-gaap_truenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00<div> Revenue Recognition We generate revenue from collaboration and license agreements for the development and commercialization of our products. Collaboration and license agreements may include non-refundable upfront license fees, partial or complete reimbursement of research and development costs, contingent consideration payments based on the achievement of defined collaboration objectives and royalties on sales of commercialized products. Our performance obligations under our collaborations include the transfer of intellectual property rights (licenses), obligations to provide research and development services and related materials and obligations to participate on certain development and/or commercialization committees with the collaborators. Payments that are contingent upon achievement of a substantive milestone are recognized in their entirety in the period in which the milestone is achieved. Milestones are defined as an event that can only be achieved based on our performance and there is substantive uncertainty about whether the event will be achieved at the inception of the arrangement. Events that are contingent only on the passage of time or only on counterparty performance are not considered milestones subject to this guidance. Further, the amounts received must relate solely to prior performance, be reasonable relative to all of the deliverables and payment terms within the agreement and commensurate with our performance to achieve the milestone after commencement of the agreement. Amounts from sales of licenses are recognized as revenue, as licensing of intellectual property is one of our principal or major ongoing activities. Amounts received as funding of research and development activities are recognized as revenue if the collaboration arrangement involves the sale of our research or development services at amounts that exceed our cost. However, such funding is recognized as a reduction in research and development expense when we engage in a research and development project jointly with another entity, with both entities participating in project activities and sharing costs and potential benefits of the arrangement. Amounts related to research and development funding are recognized as the related services or activities are performed, in accordance with the contract terms. Payments may be made to or by us based on the number of full-time equivalent researchers assigned to the collaboration project and the related research and development expenses incurred. </div>falsefalsefalsenonnum:textBlockItemTypenaDisclosure of accounting policy for revenue recognition. If the entity has different policies for different types of revenue transactions, the policy for each material type of transaction is generally disclosed. If a sales transaction has multiple element arrangements (for example, delivery of multiple products, services or the rights to use assets) the disclosure may indicate the accounting policy for each unit of accounting as well as how units of accounting are determined and valued. The disclosure may encompass important judgment as to appropriateness of principles related to recognition of revenue. The disclosure also may indicate the entity's treatment of any unearned or deferred revenue that arises from the transaction.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section 50 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=6367646&loc=d3e18780-107790 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6367646&loc=d3e18726-107790 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Staff Accounting Bulletin (SAB) -Number Topic 13 -Section B -Paragraph Question 1 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 605 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SAB TOPIC 13.B.Q1) -URI http://asc.fasb.org/extlink&oid=6600647&loc=d3e214044-122780 Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Principles Board Opinion (APB) -Number 22 -Paragraph 8, 12, 13 -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 -Topic 235 -SubTopic 10 -Section 50 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=6367646&loc=d3e18823-107790 false0Revenue Recognition10false 4us-gaap_ForeignCurrencyTransactionsAndTranslationsPolicyTextBlockus-gaap_truenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00<div> Foreign Currency Transactions and Hedging We have transactions denominated in foreign currencies, primarily the Euro, and, as a result, are exposed to changes in foreign currency exchange rates. We manage a portion of these cash flow exposures through the purchase of Euros and the use of foreign currency forward contracts. Our foreign currency forward contracts are not designated as hedges for accounting purposes. Gains or losses on foreign currency forward contracts are intended to offset gains or losses on the underlying net exposures in an effort to reduce the earnings and cash flow volatility resulting from fluctuating foreign currency exchange rates. Foreign currencies and our foreign currency forward contracts are marked to market at the end of each period and recorded as gains and losses in the condensed statements of operations. Our foreign exchange forward contracts expose us to credit risk to the extent that the counterparty, a major financial institution, is unable to meet the terms of the agreement. Our management does not expect material losses as a result of defaults by the counterparty. </div>falsefalsefalsenonnum:textBlockItemTypenaDisclosure of accounting policy for (1) transactions denominated in a currency other than the reporting enterprise's functional currency, (2) translating foreign currency financial statements that are incorporated into the financial statements of the reporting enterprise by consolidation, combination, or the equity method of accounting, and (3) remeasurement of the financial statements of a foreign reporting enterprise in a hyperinflationary economy.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section 50 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=6367646&loc=d3e18780-107790 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 830 -SubTopic 20 -URI http://asc.fasb.org/subtopic&trid=2175856 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 830 -SubTopic 10 -URI http://asc.fasb.org/subtopic&trid=2175826 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 830 -SubTopic 30 -URI http://asc.fasb.org/subtopic&trid=2175892 Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 52 -Paragraph 5, 7-20, 80 -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. false0Foreign Currency Transactions and Hedging11false 4us-gaap_EarningsPerSharePolicyTextBlockus-gaap_truenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00<div> Net Income (Loss) per Share Attributable to Common Stockholders Basic and diluted net income (loss) per share attributable to common stockholders is calculated in conformity with the two-class method required for companies with participating securities. Under the two-class method, in periods when we have net income, basic net income attributable to common stockholders is determined by allocating undistributed earnings, calculated as net income less current period convertible preferred stock noncumulative dividends, between the common stock and the convertible preferred stock. In computing diluted net income attributable to common stockholders, undistributed earnings are re-allocated to reflect the potential impact of dilutive securities. Basic net loss per share attributable to common stockholders is calculated by dividing the net loss attributable to common stockholders by the weighted-average number of shares of common stock outstanding for the period. The diluted net income per share attributable to common stockholders is computed by giving effect to all potential dilutive common stock equivalents outstanding for the period. In periods when we have incurred a net loss, convertible preferred stock, options and warrants to purchase common stock and convertible preferred stock warrants are considered common stock equivalents but have been excluded from the calculation of diluted net loss per share attributable to common stockholders as their effect is antidilutive. </div>falsefalsefalsenonnum:textBlockItemTypenaDisclosure of accounting policy for computing basic and diluted earnings or loss per share for each class of common stock and participating security. Addresses all significant policy factors, including any antidilutive items that have been excluded from the computation and takes into account stock dividends, splits and reverse splits that occur after the balance sheet date of the latest reporting period but before the issuance of the financial statements.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section 50 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=6367646&loc=d3e18780-107790 Reference 2: 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 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 260 -SubTopic 10 -URI http://asc.fasb.org/subtopic&trid=2144384 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 128 -Paragraph 40 -Subparagraph a -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. 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This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. false0Net Income (Loss) and Net Income (Loss) per Share Attributable to Common StockholdersfalseSummary of Significant Accounting Policies (Policies)UnKnownUnKnownUnKnownUnKnowntruefalsefalseSheethttp://www.portola.com/20130630/taxonomy/role/DisclosureSummaryOfSignificantAccountingPoliciesPolicies111