| Organization and Description of Business (Policies) | 3 Months Ended |
| Mar. 31, 2016 |
| Organization Consolidation And Presentation Of Financial Statements [Abstract] | |
| Liquidity And Going Concern | Liquidity and Going Concern The Company has incurred significant losses and negative cash flows from operations since its inception and had an accumulated deficit of $182.8 million at March 31, 2016. As of March 31, 2016, the Company had cash and cash equivalents of $23.8 million, and $15.9 million On April 14, 2016, the Company acquired 98.3% of the outstanding common stock of Allenex AB (“Allenex”). Allenex is a transplant diagnostic company based in Stockholm, Sweden that develops, manufactures, and sells products that help match donor organs with potential recipients prior to transplantation. Allenex has 58 employees. Under the terms of the Conditional Share Purchase Agreements entered into on December 16, 2015, as amended and the tender offer prospectus dated March 7, 2016, and as a result of the tender offer, the purchase consideration is expected to total approximately $35.0 million, consisting of $27.8 million of cash, of which approximately $6.2 million is deferred purchase consideration and payable to Midroc Invest AB, FastPartner AB and Xenella Holding AB (collectively, the “Majority Shareholders”) no later than March 31, 2017, and the issuance of 1,375,029 shares of the Company’s common stock valued at $7.2 million. Additionally, $8.0 million of cash purchase consideration payable to the Majority Shareholders of Allenex is being held in escrow by the Company and relates to a commitment by the Majority Shareholders of Allenex to purchase the Company’s equity securities in a future financing (“Subsequent Financing”). The equity securities are expected to be sold no later than 30 days following the receipt of certain Company stockholder approvals required pursuant to the rules of the NASDAQ Stock Market (the “Requisite Stockholder Approval”), which is expected to occur on June 16, 2016, on terms, including price, substantially equivalent to the terms of a Private Placement described below. The Company intends to initiate compulsory acquisition proceedings under Swedish law to purchase the remaining shares of Allenex. See Note 11 for more detail about the Allenex acquisition. On April 14, 2016, the Company completed the sale of 591,860 units (“Units”) to certain accredited investors (the “Private Placement”) at a purchase price of $23.94 per Unit. On closing on April 14, 2016, the aggregate gross proceeds to the Company from the Private Placement were approximately $14.1 million. Concurrently, the Company also entered into commitment letters (the “Commitment Letters”) pursuant to which the Majority Shareholders of Allenex agreed to purchase the Company’s equity securities in a Subsequent Financing, as described above. If the Subsequent Financing is not completed within 30 days of the Requisite Stockholder Approval, and provided that the Loan Agreement (as defined in Note 9) is still in place, the Lender (as defined in Note 9) has the right to require that the Company complete the Subsequent Financing and issue securities to the Majority Shareholders in exchange for the $8.0 million of cash held in escrow. If neither the Company nor the Lender exercise their rights by September 30, 2016, the $8.0 million held in escrow will be released to the Majority Shareholders without any further obligation on the part of the Majority Shareholders of Allenex. The Company made payments of approximately $1.1 million and $97,000 in placement fees and other offering expenses, respectively, to placement agents in connection with the sale of the 591,860 Units in the Private Placement. Following the closing of the Private Placement, the Company agreed to a number of requirements such as submitting the Private Placement to the Company’s stockholders for approval, which is expected to be approved after the receipt of the Requisite Stockholder Approval expected on June 16, 2016, granting certain registration rights, including the registration of shares sold in the Private Placement on a registration statement on Form S-3 within 45 days of closing. Additionally, if the Company fails to file an effective registration statement on Form S-3 within 45 days of closing the Private Placement, the Company shall be obligated to pay an aggregate penalty amount equal to approximately $0.3 million for each month that the Company has not filed the required registration statement, up to a maximum of $1.4 million. See Note 11 for more detail about the Private Placement. The Company will require additional financing and/or refinancing to fund working capital, repay debt and to pay its obligations. A potential working capital benefit of refinancing the Company’s existing debt obligations is deferral of debt payments otherwise due in 2016. The Company may pursue financing and refinancing opportunities in both the private and public debt and equity markets through sales of debt or equity securities. Absent the receipt of additional funding or refinancing, the Company will exhaust its cash and cash equivalents in December |
| Basis of Presentation | 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 follow 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 condensed balance sheet as of December 31, 2015 has been derived from audited financial statements as of that date but does not include all of the financial information required by U.S. GAAP for complete financial statements. Operating results for the three months ended March 31, 2016 are not necessarily indicative of the results that may be expected for the year ending December 31, 2016. The accompanying unaudited 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, 2015 included in the Company’s Annual Report on Form 10-K filed on March 29, 2016 with the SEC. |
| Use of Estimates | Use of Estimates The preparation of unaudited 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 and disclosure of contingent assets and liabilities and the reported amounts of revenues and expenses in the unaudited condensed financial statements and accompanying notes. On an ongoing basis, management evaluates its estimates, including those related to (i) revenue recognition, (ii) the differences between amounts billed and estimated receipts from payers, (iii) the determination of the accruals for clinical studies, (iv) the determination of refunds to be requested by third-party payers, (v) the fair value of assets and liabilities, (vi) the valuation of warrants to purchase common stock, (vii) the fair value of contingent consideration in a business acquisition, (viii) the fair value of embedded derivatives, (ix) measurement of stock-based compensation expense, (x) the determination of the valuation allowance and estimated tax benefit associated with deferred tax assets and net deferred tax liability, (xi) any impairment of long-lived assets including in-process technology and goodwill and (xii) legal contingencies. Actual results could differ from those estimates. |
| Concentrations of Credit Risk and Other Risks and Uncertainties | Concentrations of Credit Risk and Other Risks and Uncertainties Financial instruments that potentially subject the Company to credit risk consist of cash and cash equivalents and accounts receivable. The Company’s policy is to invest its cash and cash equivalents in money market funds, obligations of U.S. government agencies and government-sponsored entities, commercial paper, and various bank deposit accounts. These financial instruments were held in Company accounts at two financial institutions. The counterparties to the agreements relating to the Company’s investments consist of financial institutions of high credit standing. The Company is exposed to credit risk in the event of default by the financial institutions to the extent of amounts recorded on the balance sheets which may be in excess of insured limits. The Company is also subject to credit risk from its accounts receivable which are derived from revenue earned from AlloMap tests provided for patients located in the U.S. and billed to various third-party payers. The Company has not experienced any significant credit losses and does not generally require collateral on receivables. |
| Cash Equivalents | Cash Equivalents Cash equivalents consist of short-term, highly liquid investments with original maturities of three months or less from the date of purchase. Cash equivalents consist primarily of amounts invested in money market funds. |
| Purchased Intangible Assets | Purchased Intangible Assets Acquired intangible assets with indefinite useful lives are related to in-process research and development or IPR&D, projects and are measured at their respective fair values as of the acquisition date. The Company does not amortize intangible assets with indefinite useful lives. Intangible assets related to IPR&D projects are considered to be indefinite-lived until the completion or abandonment of the associated R&D efforts. If and when development is complete, which generally occurs if and when regulatory approval to market a product is obtained, the associated assets would be deemed finite-lived and would then be amortized based on their respective estimated useful lives at that point in time. The Company tests IPR&D for impairment on an annual basis and in between annual tests if it becomes aware of events or changes that would indicate that it is more likely than not that the fair value of the assets is below their carrying amounts. The IPR&D annual impairment test is performed as of December 1 of each fiscal year. If the fair value exceeds the carrying value, then there is no impairment. Impairment losses on indefinite-lived intangible assets are recognized based solely on a comparison of the fair value of the asset to its carrying value, without consideration of any recoverability test. The Company has not identified any such impairment losses to date. |
| Impairment of Long-lived Assets | Impairment of Long-lived Assets The Company evaluates its long-lived assets for indicators of possible impairment when events or changes in circumstances indicate the carrying amount of an asset may not be recoverable. The Company then compares the carrying amounts of the assets with the future net undiscounted cash flows expected to be generated by such asset. Should an impairment exist, the impairment loss would be measured based on the excess carrying value of the asset over the asset’s fair value determined using discounted estimates of future cash flows. The Company has not identified any such impairment losses to date. |
| Goodwill | Goodwill Goodwill represents the excess of the cost of an acquisition over the sum of the amounts assigned to tangible and identifiable intangible assets acquired, less liabilities assumed. Goodwill is not subject to amortization, but is tested for impairment on an annual basis and whenever events or changes in circumstances indicate the carrying amount of these assets may not be recoverable. The Company has determined that it operates in a single segment and has a single reporting unit associated with the development and commercialization of diagnostic products. In the event that the Company determines that it is more likely than not that the carrying value of the reporting unit is higher than its fair value, quantitative testing is performed comparing recorded values to estimated fair values. If impairment is present, it is measured as the excess of recorded goodwill over its implied fair value. The Company performs its annual evaluation of goodwill on December 1 of each fiscal year. There have been no impairments recorded to date. |
| Fair Value of Financial Instruments | Fair Value of Financial Instruments Fair value is defined as the price that would be received from selling an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. When determining fair value, the Company considers the principal or most advantageous market in which the Company would transact, and it takes into consideration the assumptions that market participants would use when pricing the asset or liability. The Company’s assessment of the significance of a particular input to the fair value measurement of an asset or liability requires management to make judgments and to consider specific characteristics of that asset or liability. The carrying amounts of certain of the Company’s financial instruments, including cash equivalents, accounts receivable, accounts payable, and accrued liabilities, approximate fair value due to their short maturities. |
| Testing Revenue | Testing Revenue The Company recognizes revenues for tests delivered when the following criteria are met: (i) persuasive evidence that an arrangement exists; (ii) delivery has occurred or services rendered; (iii) the fee is fixed or determinable; and (iv) collectability is reasonably assured. The first criterion is satisfied when a third-party payer makes a coverage decision or enters into a contractual arrangement with the Company for the test. The second criterion is satisfied when the Company performs the test and delivers the test result to the ordering physician. The third criterion is satisfied if the third-party payer’s coverage decision or reimbursement contract specifies a price for the test. The fourth criterion is satisfied based on management’s judgments regarding the collectability of the fees charged under the arrangement. Such judgments include review of past payment history. AlloMap testing may be considered investigational by some payers and not covered under their reimbursement policies. Others may cover the test, but not pay a set or determinable amount. As a result, in the absence of a reimbursement agreement or sufficient payment history, collectability cannot reasonably be assured so revenue is not recognized at the time the test is delivered. If all criteria set forth above are met, revenue is recognized. When the first, third or fourth criteria are not met but third-party payers make a payment to the Company for tests performed, the Company recognizes revenue on the cash basis in the period in which the payment is received. Revenue is recognized on the accrual basis net of adjustments for differences between amounts billed and the estimated receipts from payers. The amount the Company expects to collect may be lower than the agreed upon amount due to several factors, such as the amount of patient co-payments, the existence of secondary payers and claim denials. Estimated receipts are based upon historical payment practices of payers. Differences between estimated and actual cash receipts are recorded as an adjustment to revenue, which have been immaterial to date. During the three months ended March 31, 2016, the Company changed its revenue recognized from one of its payers from the cash basis to the accrual basis based on its consistent history of obtaining timely reimbursement from this payer. The impact of this change in accounting estimate was insignificant to revenues and loss per share for the three months ended March 31, 2016. During the three months ended March 31, 2015, the Company changed its revenue recognized from two of its payers from the cash basis to the accrual basis based on the Company’s consistent history of obtaining timely reimbursement from these two payers. The impact of this change in accounting estimate was to increase revenues by $0.1 million and to change loss per share from $0.20 to $0.19 for the three months ended March 31, 2015. |
| Collaboration and License Revenue | Collaboration, License and Other Revenue The Company generates revenue from collaboration and license agreements. Collaboration and license agreements may include non-refundable upfront payments, partial or complete reimbursement of research and development costs, contingent payments based on the occurrence of specified events under the agreements, license fees and royalties on sales of products or product candidates if they are successfully commercialized. The Company’s performance obligations under the collaborations may include the transfer of intellectual property rights in the form of licenses, obligations to provide research and development services and obligations to participate on certain development committees with the collaboration partners. The Company makes judgments that affect the periods over which it recognizes revenue. The Company periodically reviews its estimated periods of performance based on the progress under each arrangement and accounts for the impact of any change in estimated periods of performance on a prospective basis. The Company recognizes contingent consideration received from the achievement of a substantive milestone in its entirety in the period in which the milestone is achieved, which the Company believes is consistent with the substance of its performance under its various license and collaboration agreements. The Company did not recognize any milestones during the three months ended March 31, 2016 and 2015. |
| Cost of Testing | Cost of Testing Cost of testing reflects the aggregate costs incurred in delivering the Company’s AlloMap test results to clinicians. The components of cost of testing are materials and service costs, direct labor costs, including stock-based compensation, equipment and infrastructure expenses associated with testing samples, shipping, logistics and specimen processing charges to collect and transport samples and allocated overhead including rent, information technology, equipment depreciation and utilities and royalties. Costs associated with performing tests (except royalties) are recorded as the test is processed regardless of whether and when revenue is recognized with respect to that test. As a result, our cost of testing as a percentage of revenue may vary significantly from period to period because we do not recognize all revenue in the period in which the associated costs are incurred. Royalties for licensed technology, calculated as a percentage of test revenues, are recorded as license fees in cost of testing at the time the test revenues are recognized. |
| Business Combinations | Business Combinations The Company determines and allocates the purchase price of an acquired business to the tangible and identifiable intangible assets acquired and liabilities assumed based on their estimated fair values as of the business combination date, including identifiable intangible assets which either arise from a contractual or legal right or are separable from goodwill. The Company bases the estimated fair value of identifiable intangible assets acquired in a business combination on independent valuations that use information and assumptions provided by management, which consider management’s best estimates of inputs and assumptions that a market participant would use. The Company allocates any excess purchase price over the estimated fair value assigned to the net tangible and identifiable intangible assets acquired and liabilities assumed to goodwill. The use of alternative valuation assumptions, including estimated revenue projections, growth rates, royalty rates, cash flows, discount rates, estimated useful lives and probabilities surrounding the achievement of contingent milestones could result in different purchase price allocations and amortization expense in current and future periods. In those circumstances where an acquisition involves a contingent consideration arrangement that meets the definition of a liability under ASC 480, Distinguishing Liabilities from Equity Transaction costs associated with these acquisitions are expensed as incurred in general and administrative expenses. Results of operations and cash flows of acquired companies are included in the Company’s operating results from the date of acquisition. |
| Stock-based Compensation | Stock-based Compensation The Company uses the Black-Scholes Model, which requires the use of estimates such as stock price volatility and expected option lives, to value employee stock options. The Company estimates the expected option lives using historical data, volatility using its own historical stock prices and stock prices of peer companies in the diagnostics industry, risk-free rates based on the implied yield currently available in the U.S. Treasury zero-coupon issues with a remaining term equal to the expected option lives, and dividend yield based on the Company’s expectations and historical data. The Company uses the straight-line attribution method for recognizing compensation expense. Compensation expense is recognized on awards ultimately expected to vest and reduced for forfeitures that are estimated at the time of grant and revised, if necessary, in subsequent periods if actual forfeitures differ from those estimates. Forfeitures are estimated based on the Company’s historical experience. Compensation expense for stock options issued to nonemployees is calculated using the Black-Scholes Model and is recorded over the service performance period. Options subject to vesting are required to be periodically remeasured over their service performance period, which is generally the same as the vesting period. |
| Warrants | Warrants The Company had freestanding warrants enabling counterparties to purchase shares of its convertible preferred stock as of December 31, 2013, which were converted to purchase common stock on the Company’s IPO date. Freestanding warrants for convertible preferred stock that were contingently redeemable were classified as liabilities on the balance sheet and recorded at their estimated fair value. These warrants were remeasured at each balance sheet date and any change in estimated fair value was recognized in other expense on the condensed statements of operations. Upon the completion of the Company’s IPO in July 2014, preferred stock warrants were converted into warrants to purchase common stock, and accordingly, the liability was reclassified to equity and became no longer subject to remeasurement. |
| Comprehensive Loss | Comprehensive Loss Net loss and comprehensive loss are the same for all periods presented. |
| Recent Accounting Pronouncements | Recent Accounting Pronouncements In August 2014, the FASB issued Accounting Standards Update No. 2014-15, Presentation of Financial Statements―Going Concern (Subtopic 205-40), Disclosure of Uncertainties about an Entity’s Ability to Continue as a Going Concern In April 2015, the FASB issued ASU 2015-05, Intangibles—Goodwill and Other—Internal Use Software (Subtopic 350-40) In November 2015, the FASB issued ASU 2015-17, Income Taxes (Topic 740): Balance Sheet Classification of Deferred Taxes, In February 2016, the FASB issued ASU 2016-02, Leases In March 2016, the FASB issued ASU 2016-06, Derivatives and Hedging: Contingent Put and Call Options in Debt Instruments In April 2016, the FASB issued ASU 2016-10, Revenue from Contracts with Customers (Topic 606): Identifying Performance Obligations and Licensing. Revenue from Contracts with Customers (Topic 606): Principal versus Agent Considerations (Reporting Revenue Gross versus Net) Revenue from Contracts with Customers (Topic 606), |
