Athersys, Inc / New (ATHXQ) 10-Q 10 May 18 2018 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2018	May 01, 2018
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Mar. 31, 2018
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	Q1
Trading Symbol	ATHX
Entity Registrant Name	ATHERSYS, INC / NEW
Entity Central Index Key	1,368,148
Current Fiscal Year End Date	--12-31
Entity Filer Category	Accelerated Filer
Entity Common Stock, Shares Outstanding		137,958,545

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents	$ 49,673	$ 29,316
Accounts receivable	759	586
Prepaid expenses and other	1,020	1,135
Total current assets	58,422	31,190
Equipment, net	2,312	2,206
Other	200	197
Total assets	60,934	33,593
Current liabilities:
Accounts payable	8,092	4,469
Accrued compensation and related benefits	743	1,065
Accrued clinical trial costs	430	1,453
Accrued expenses	389	425
Accrued license fee expense	1,665	1,900
Deferred revenue	250	771
Total current liabilities	11,569	10,083
Stockholders' equity:
Preferred stock, at stated value; 10,000,000 shares authorized, and no shares issued and outstanding at March 31, 2018 and December 31, 2017
Common stock, $0.001 par value; 300,000,000 shares authorized, and 137,958,545 and 122,077,453 shares issued and outstanding at March 31, 2018 and December 31, 2017, respectively	138	122
Additional paid-in capital	406,308	373,884
Accumulated deficit	(358,914)	(350,630)
Total stockholders' equity	47,532	23,376
Total liabilities and stockholders' equity	60,934	33,593
Healios License Agreement [Member]
Current assets:
Accounts receivable	132	153
Contractual right to consideration from Healios	1,538
Other asset	5,300
Current liabilities:
Deferred revenue	0
Advance	$ 1,833	$ 134

Condensed Consolidated Balance3

Condensed Consolidated Balance Sheets (Parenthetical) - $ / shares	Mar. 31, 2018	Dec. 31, 2017
Statement of Financial Position [Abstract]
Preferred stock, shares authorized	10,000,000	10,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.001	$ 0.001
Common stock, shares authorized	300,000,000	300,000,000
Common stock, shares issued	137,958,545	122,077,453
Common stock, shares outstanding	137,958,545	122,077,453

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations and Comprehensive Loss - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Revenues
Contract revenue from Healios	$ 348	$ 28
Royalty and contract revenue	401	1,232
Grant revenue	317	210
Total revenues	1,066	1,470
Costs and expenses
Research and development	8,850	5,633
General and administrative	2,655	2,071
Depreciation	186	164
Total costs and expenses	11,691	7,868
Gain from insurance proceeds	363
Loss from operations	(10,262)	(6,398)
Income from change in fair value of warrants		728
Other income, net	107	39
Net loss and comprehensive loss	$ (10,155)	$ (5,631)
Net loss per common share, basic and diluted	$ (0.08)	$ (0.06)
Weighted average shares outstanding, basic and diluted	126,897,425	102,047,062

Condensed Consolidated Stateme5

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Operating activities
Net loss	$ (10,155)	$ (5,631)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation	186	164
Stock-based compensation	813	689
Change in fair value of warrant liabilities		(728)
Changes in operating assets and liabilities:
Accounts receivable	(173)	(1,168)
Prepaid expenses and other	127	(231)
Accounts payable and accrued expenses	1,992	1,022
Deferred revenue		503
Net cash used in operating activities	(5,678)	(5,380)
Investing activities
Purchases of equipment	(292)	(134)
Net cash used in investing activities	(292)	(134)
Financing activities
Proceeds from issuance of common stock, net	26,411	20,877
Shares retained for withholding tax payments on stock-based awards	(84)	(37)
Proceeds from exercise of warrants		1,861
Net cash provided by financing activities	26,327	22,701
Increase in cash and cash equivalents	20,357	17,187
Cash and cash equivalents at beginning of the period	29,316	14,753
Cash and cash equivalents at end of the period	49,673	$ 31,940
Healios License Agreement [Member]
Changes in operating assets and liabilities:
Accounts receivable	(51)
Advance	$ 1,583

Background and Basis of Present

Background and Basis of Presentation	3 Months Ended
	Mar. 31, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Background and Basis of Presentation	1. Background and Basis of Presentation We are an international biotechnology company that is focused primarily in the field of regenerative medicine and operate in one business segment. Our operations consist of research and later-stage product development activities. We incurred losses since our inception in 1995 and had an accumulated deficit of $359 million at March 31, 2018. We will require substantial additional capital to continue our research and development programs, including progressing our clinical product candidates to commercialization and preparing for commercial-scale manufacturing. At March 31, 2018, we had available cash and cash equivalents of $49.7 million plus, under a proposed expansion to a collaboration discussed herein, our collaborator has funded $10 million as an expansion fee into an escrow account in March 2018 that is due to be released to us by June 1, 2018. We believe that these funds, used to execute our existing operating plans, are sufficient to meet our obligations as they come due at least for a period of twelve months from the date of the issuance of these unaudited condensed consolidated financial statements. In the longer term, we will make use of available cash, but will have to continue to generate additional capital to meet our needs through new and existing collaborations and related license fees and milestones, the sale of equity securities from time to time, including through our equity purchase agreement, grant-funding opportunities, deferring certain discretionary costs and staging certain development costs, as needed. The accompanying unaudited condensed consolidated financial statements should be read in conjunction with the audited financial statements and notes thereto included in our Annual Report on Form 10-K S-X. The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. Our critical accounting policies, estimates and assumptions are described in “Management’s Discussion and Analysis of Financial Condition and Results of Operations,” which is included below in this Quarterly Report on Form 10-Q.

Recently Issued Accounting Stan

Recently Issued Accounting Standards	3 Months Ended
	Mar. 31, 2018
Accounting Changes and Error Corrections [Abstract]
Recently Issued Accounting Standards	2. Recently Issued Accounting Standards In February 2016, the Financial Accounting Standards Board (“FASB”) issued ASU 2016-02, right-of-use In May 2017, the FASB issued ASU 2017-09,

Revenue Recognition and Adoptio

Revenue Recognition and Adoption of New Accounting Pronouncement	3 Months Ended
	Mar. 31, 2018
Revenue from Contract with Customer [Abstract]
Revenue Recognition and Adoption of New Accounting Pronouncement	3. Revenue Recognition and Adoption of New Accounting Pronouncement Our license and collaboration agreements may contain multiple elements, including license and technology access fees, research and development funding, product supply revenue, cost-sharing, milestones and royalties. The deliverables under such an arrangement are evaluated under ASU No. 2014-09, We adopted this guidance as of January 1, 2018, utilizing the modified retrospective transition method applied to contracts that were not complete as of January 1, 2018. We evaluated all of our collaborative agreements on a contract-by-contract Milestone Payments Topic 606 does not contain guidance specific to milestone payments, but rather requires potential milestone payments to be considered in accordance with the overall model of Topic 606. As a result, revenues from contingent milestone payments is recognized based on an assessment of the probability of milestone achievement and the likelihood of a significant reversal of such milestone revenue at each reporting date. This assessment may result in recognizing milestone revenue before the milestone event has been achieved. Since the milestones in the Healios arrangement are generally related to development and commercial milestone achievement by Healios, we have not included any of the Healios milestones in the estimated transaction price of the Healios arrangement, since they would be constrained, as a significant reversal of revenue could result in future periods. Other than for our collaboration with Healios that has remaining deliverables, we had recognized the full amount of license fees under our collaboration agreements as contract revenue under the prior guidance associated with multiple-element arrangements, since the performance periods for our multiple element arrangements have concluded. The events triggering any future contingent milestone payments from these arrangements were determined to be non-substantive Grant revenue Grant revenue, which is not within the scope of Topic 606, consists of funding under cost reimbursement programs primarily from federal and non-profit Royalty Revenue We recognize royalty revenue relating to the sale by a licensee of our licensed products. Royalty revenue is recognized upon the later to occur of (i) achievement of the collaborator’s underlying sales or (ii) satisfaction of any performance obligation(s) related to these sales, in each case assuming the license to our intellectual property is deemed to be the predominant item to which the sales-based royalties relate. Deferred Revenue Amounts received from customers or collaborators in advance of our performance of services or other deliverables is included in deferred revenue. For product supply, we typically invoice our customers a portion of the purchase order in advance, followed by invoices as product is released and available for pick-up. non-current. Advance from Healios As further described in Note 6, proceeds from Healios that relate specifically to the cost-sharing arrangement for Healios’ stroke study in Japan that may result in a net reduction in the proceeds we receive from Healios upon the achievement of future milestones are recognized as non-current Effect of Adoption of Topic 606 Our arrangement with Healios was the only collaboration that was impacted by the adoption of Topic 606. Notes 6 and 8 further describe our arrangement with Healios, including modifications that have resulted. We have applied the practical expedient under Topic 606 and have reflected the aggregate effect of all modifications at January 1, 2018. The components of the cumulative effect of the changes made to our consolidated January 1, 2018 balance sheet for the adoption of Topic 606 were as follows (in thousands): As of December 31, Adjustments Due As of January 1, Assets Accounts receivable - Healios $ 153 $ 30 $ 183 Contractual right to consideration from Healios $ — $ 1,436 $ 1,436 Liabilities Deferred revenue - Healios $ (521 ) $ 521 $ — Advance from Healios $ (134 ) $ (116 ) $ (250 ) Equity Accumulated deficit $ 350,630 $ (1,871 ) $ 348,759 In accordance with the new revenue recognition requirements, the disclosure of the impact of adoption on our condensed consolidated balance sheet and statement of operations for the three months ended March 31, 2018 was as follows (in thousands, except per share data): As of March 31, 2018 As Reported Balances without Effect of Change Assets Contractual right to consideration from Healios $ 1,538 $ — $ 1,538 Liabilities Deferred revenue - Healios $ — $ (259 ) $ 259 Equity Accumulated deficit $ 358,914 $ 360,711 $ (1,797 ) Three months ended March 31, 2018 As Reported Balances without Effect of Change Revenues Contract revenues - Healios $ 348 $ 422 $ (74 ) Net loss $ (10,155 ) $ (10,081 ) $ 74 Net loss per common share Basic and diluted $ (0.08 ) $ (0.08 ) $ — The adoption of Topic 606 had no impact on our total cash flows from operations. Disaggregation of Revenues We recognize license-related amounts, including upfront payments, exclusivity fees, additional disease indication fees, and development, regulatory and sales-based milestones at a point in time when earned. Similarly, product supply revenue is recognized at a point in time, while service revenue is recognized when earned over time. The following table presents our contract revenues from Healios disaggregated by recognition at a point in time and over time (in thousands). Three months ended March 31, 2018 Recognized at Point in Time Recognized Over Time Total Contract Revenues - Healios Product supply revenue $ 227 $ — 227 Service revenue — 121 121 Total $ 227 $ 121 $ 348 4. Net Loss per Share Basic and diluted net loss per share have been computed using the weighted-average number of shares of common stock outstanding during the period. We have outstanding stock-based awards that are not used in the calculation of diluted net loss per share because to do so would be antidilutive. We have one warrant outstanding that was issued to Healios in March 2018, but Healios is not yet permitted to exercise any of the shares underlying the warrant. Refer to Note 8 for additional details. The following instruments were excluded from the calculation of diluted net loss per share because their effects would be antidilutive: Three months ended March 31, 2018 2017 Stock-based awards 10,294,613 10,091,837 Warrants – see Note 8 20,000,000 — Total 30,294,613 10,091,837

Net Loss per Share

Net Loss per Share	3 Months Ended
	Mar. 31, 2018
Earnings Per Share [Abstract]
Net Loss per Share	4. Net Loss per Share Basic and diluted net loss per share have been computed using the weighted-average number of shares of common stock outstanding during the period. We have outstanding stock-based awards that are not used in the calculation of diluted net loss per share because to do so would be antidilutive. We have one warrant outstanding that was issued to Healios in March 2018, but Healios is not yet permitted to exercise any of the shares underlying the warrant. Refer to Note 8 for additional details. The following instruments were excluded from the calculation of diluted net loss per share because their effects would be antidilutive: Three months ended March 31, 2018 2017 Stock-based awards 10,294,613 10,091,837 Warrants – see Note 8 20,000,000 — Total 30,294,613 10,091,837

Proceeds from Insurance

Proceeds from Insurance	3 Months Ended
	Mar. 31, 2018
Unusual or Infrequent Items, or Both [Abstract]
Proceeds from Insurance	5. Proceeds from Insurance In 2016, our facility sustained flood damage representing both an unusual and infrequent event. Insurance proceeds are recorded to the extent of the losses and then, only if recovery is realized or probable. Any gains in excess of losses are recognized only when the contingencies regarding the recovery are resolved, and the amount is fixed or determinable. We recognized an insurance recovery gain of $0.4 million in the first quarter of 2018 as additional insurance proceeds were received.

Collaborative Arrangements and

Collaborative Arrangements and Revenue Recognition	3 Months Ended
	Mar. 31, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Collaborative Arrangements and Revenue Recognition	6. Collaborative Arrangements and Revenue Recognition Healios 2016 Inception of License Arrangement In 2016, we entered into a license agreement (“Healios Agreement”) with Healios to develop and commercialize MultiStem cell therapy for ischemic stroke in Japan and to provide Healios with access to our proprietary MAPC technology for use in its “organ bud” program, initially for transplantation to treat liver disease or dysfunction. Under the Healios Agreement, Healios obtained a right to expand the scope of the collaboration to include the exclusive rights to develop and commercialize MultiStem for the treatment of certain additional indications in Japan, which include acute respiratory distress syndrome (“ARDS”), and, as addressed herein, plans for an expansion of the collaboration are underway. Under the terms of the Healios Agreement, we received a nonrefundable, up-front For the ischemic stroke indication, we may also receive additional success-based development, regulatory approval and sales milestones, which are non-refundable non-creditable If Healios exercised its option to expand the collaboration to include ARDS and another indication in the orthopedic area under the Healios Agreement, we would be entitled to receive a cash payment of $10 million at the time of exercise and royalties from product sales and success-based development, regulatory approval and sales milestones, as well as payments for product supply related to the additional indications covered by the option. Under the proposed expansion plans addressed herein, at a minimum, Healios would exercise its option to include the ARDS field under the Healios Agreement, and the $10 million expansion fee was funded by Healios into an escrow account in March 2018, which is due to be released to us by June 1, 2018. For the “organ bud” product, we are entitled to receive a fractional royalty percentage on net sales of the “organ bud” products and will receive payments for manufactured product supplied to Healios under a manufacturing supply agreement. Additionally, we have a right of first negotiation for commercialization of an “organ bud” product in North America, with such right expiring on certain dates in the future. For the Healios arrangement, we identified all material performance obligations, which included a license to our technology, product supply services, and services related to transfer technology to a contract manufacture on Healios’ behalf. In order to determine the transaction price, in addition to the upfront payment, we estimated the amount of variable consideration at the outset of the contract utilizing the expected value or most likely amount method, depending on the facts and circumstances relative to the contract. We constrain, or reduce, the estimates of variable consideration if it is probable that a significant reversal of previously recognized revenue could occur throughout the life of the contract. Both the likelihood and magnitude of a potential reversal of revenue are taken into consideration. These estimates are re-assessed Once the estimated transaction price is established, amounts are allocated to the performance obligations that have been identified. The transaction price is allocated to each separate performance obligation on a relative standalone selling price basis. We must develop assumptions that require judgment to determine the relative standalone selling price in order to account for our collaborative agreements, as these assumptions typically include probabilities of obtaining marketing approval for our product candidates, estimated timing and cost of development and commercialization, estimated future cash flows from potential product sales of our product candidates, and appropriate discount and tax rates. We do not include a financing component to our estimated transaction price at contract inception unless we estimate that the performance obligations will not be satisfied within one year. We determined that the license in the Healios arrangement was distinct from the other performance obligations identified in the arrangement, and that the license was transferred to Healios and Healios was able to use and benefit from the license. Furthermore, the product supply services and the technology transfer services provided to Healios were also determined to be distinct. We then allocated the transaction price based on the relative value prescribed to the license compared to the overall arrangement. As a result of the analysis, we allocated to the license $17.3 million of the proceeds received and to be received in the future. For performance obligations satisfied over time, we apply an appropriate method of measuring progress each reporting period and, if necessary, adjust the estimates of performance and the related revenue recognition. For our technology transfer services provided to Healios that are satisfied over time, we recognize revenue in proportion to the contractual services provided. We computed the effect of the adoption of Topic 606, which is included in the cumulative effect adjustment as of January 1, 2018. Overall, the conclusions under the former guidance related to performance obligations, obligations being distinct within the contract and relative standalone selling prices did not change with the adoption of the new guidance. However, the transaction price was higher under Topic 606 since revenue recognition is no longer limited to cash proceeds received, and we were able to recognize more revenue for the delivered license. This additional revenue of $1.9 million was accounted for as a decrease to our accumulated deficit at January 1, 2018 and an increase to a contract asset and to a lesser extent, a decrease to deferred revenue. The contract asset was evaluated at March 31, 2018, noting that it is properly classified as a current asset since the conditional rights to consideration are expected to be satisfied within one year. 2017 Amendment – Cost Share In January 2017, we signed a clinical trial supply agreement for the manufacturing of investigational product for Healios for its Japan clinical study, the terms of which were consistent with the Healios Agreement. The clinical trial supply agreement was amended in July 2017 to clarify a cost-sharing arrangement associated with our supply of clinical product. The proceeds from Healios that relate specifically to the cost-sharing arrangement may result in a reduction in the proceeds we receive from Healios upon the achievement of two future milestones, and an increase to a later-stage commercial milestone. While the amendment to the supply agreement resulted in a revision to the terms associated with the product supply under the Healios Agreement, namely the cost of product supply, the revision did not affect any of the performance obligations under the overall arrangement. The cost-sharing proceeds received are recognized on the balance sheets as a non-current 2017 Technology Transfer Services In September 2017, we entered into a services agreement with Healios, in which Healios provides financial support to establish a contract manufacturer in Japan to produce product for Healios, and services began in the fourth quarter of 2017. We evaluated this agreement as combined with the Healios Agreement due to its connection to the license and the product supply under the Healios Agreement. The costs of the services, representing our performance obligation, are reimbursed by Healios at our cost. Given that Healios will benefit from the services as the services are performed, which is the intended purpose of the arrangement, we concluded that the services were distinct. We estimated the relative standalone value of the technology transfer services, which was included in the allocation of the transaction price for the overall Healios arrangement. The technology transfer services are recognized over time as the services are performed. Furthermore, in September 2017, we amended the Healios Agreement to confer to Healios a limited license to manufacture MultiStem in the event that we are acquired by a third party. Such amendment was evaluated as a combined agreement along with the Healios Agreement and had no impact on the allocation of revenue to the remaining undelivered items. 2018 Planned Expansion In March 2018, we entered into a letter of intent (as amended in April 2018, the “LOI”) with Healios to significantly expand Healios’ license to develop MultiStem products and enter into a Collaboration Expansion Agreement (the “Collaboration Expansion Agreement”). Under the terms of the LOI, we and Healios will work to execute the agreements necessary to expand the existing collaboration by May 31, 2018. If the Collaboration Expansion Agreement is entered into in accordance with the terms of the LOI, Healios would (i) expand its license to include ARDS (including idiopathic pulmonary fibrosis) and trauma in Japan, and use of MultiStem worldwide for organ buds for all organ diseases, (ii) obtain a worldwide exclusive license for use of MultiStem product to treat certain ophthalmological indications, (iii) obtain an exclusive option to a license to develop and commercialize MultiStem products for ischemic stroke, ARDS and trauma in China, and (iv) obtain certain other rights. In exchange, if the Collaboration Expansion Agreement is entered into as contemplated by the LOI, we would be entitled to receive payments of $35 million ($10 million of which was funded in an escrow account to be paid to us upon execution), as well as additional possible payments, including milestones and royalties. Under the Collaboration Expansion Agreement, the remaining $25 million payment obligation would be paid in instalments that cannot be terminated over time, and though the payments would be non-refundable, Under the binding terms of the LOI, we and Healios entered into an escrow agreement in March 2018, and Healios funded $10 million into the escrow account, which is to be paid to us no later than June 1, 2018 as either (i) a portion of the $35 million in payments associated with the execution of the Collaboration Expansion Agreement, or (ii) if Collaboration Expansion Agreement is not executed on or before May 31, 2018, payment for expanding the scope of the existing Healios Agreement to include ARDS and certain ophthalmological indications in Japan and use of MultiStem for organ buds for all organ diseases. Also see Note 3 regarding our revenue recognition policies and Note 8 regarding the equity investment made by Healios in the first quarter of 2018 in connection with the planned expansion of the collaboration, and the issuance of a warrant to Healios. Other Under our agreement with RTI to develop and commercialize biologic implants using our technology for certain orthopedic applications in the bone graft substitutes market, we are eligible to receive up to $34.5 million in remaining cash payments upon the successful achievement of certain commercial milestones, after the first commercial milestone payment of $1.0 million was received in the first quarter of 2017. No milestone revenues were received in the first quarter of 2018. In addition, we receive tiered royalties on worldwide commercial sales of implants using our technologies based on a royalty rate starting in the mid-single mid-teens, In January 2017, we received an option fee related to an agreement with a global leader in the animal health business segment to evaluate our cell therapy technology for application in an animal health area. Under the terms of the agreement, we received the payment in exchange for an exclusive period to evaluate our cell therapy technology with an option to negotiate for a license for the development and commercialization of the technology for the animal health area. The option fee is recorded as deferred revenue at March 31, 2018 since the performance obligation of granting a license has not occurred. If the option is exercised, we will include the option fee in the overall consideration for the license arrangement, to be evaluated at that time. If the option is not exercised, the option fee will be recognized as revenue at that time since there will be no more performance obligations. The evaluation of our technology for this application is currently ongoing.

Stock-based Compensation

Stock-based Compensation	3 Months Ended
	Mar. 31, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock-based Compensation	7. Stock-based Compensation We have an incentive plan that authorized an aggregate of 20,035,000 shares of common stock for awards to employees, directors and consultants. The equity incentive plan authorizes the issuance of equity-based compensation in the form of stock options, stock appreciation rights, restricted stock, restricted stock units, performance shares and units, and other stock-based awards. As of March 31, 2018, a total of 4,487,408 shares (including 241,652 shares related to an expired incentive plan) of common stock have been issued under our equity incentive plan. As of March 31, 2018, a total of 6,435,880 shares were available for issuance under our equity compensation plan, and stock-based awards to purchase 10,294,613 shares (including 941,249 shares related to an expired incentive plan) of common stock were outstanding. For the three-month periods ended March 31, 2018 and 2017, stock-based compensation expense was approximately $813,000 and $689,000, respectively. At March 31, 2018, total unrecognized estimated compensation cost related to unvested stock-based awards was approximately $6.5 million, which is expected to be recognized by the end of 2021 using the straight-line method.

Stockholders' Equity

Stockholders' Equity	3 Months Ended
	Mar. 31, 2018
Equity [Abstract]
Stockholders' Equity	8. Stockholders’ Equity Equity Issuance - Healios In March 2018, Healios purchased 12,000,000 shares of our common stock (the “Shares”) for $21,100,000, or approximately $1.76 per share, and a warrant (“Warrant”) to purchase up to an additional 20,000,000 shares of common stock (the “Warrant Shares”). In connection with the issuance of the Shares, we and Healios entered into an Investor Rights Agreement, which governs certain rights of Healios and us relating to Healios’ ownership of our common stock, including the Shares and the Warrant Shares. The Investor Rights Agreement provides for customary standstill and voting obligations, transfer restrictions and registration rights of Healios. Additionally, we agree to provide notice to Healios of certain equity issuances and to allow Healios to participate in certain issuances in order maintain its proportionate ownership of our common stock as of the time of such issuance. We further agreed under the Investor Rights Agreement that during such time as Healios beneficially owns more than 5% but less than 15.0% of our outstanding common stock, our Board of Directors (the “Board”) will nominate one of Healios’ nominees suitable to us to become a member of the Board, and during such time as Healios beneficially owns 15.0% or more of our outstanding common stock, our Board will nominate two of Healios’ nominees suitable to us to become members of the Board, at each annual election of directors. Healios’ right to nominate an individual to the Board will not commence until the Collaboration Expansion Agreement has been entered into. As a result of Healios’ ownership position in us following its investment, Healios became a related party, and the transactions with Healios are separately identified within these financial statements as they are related party transactions. The Warrant will become exercisable once Healios makes the initial payment under the planned Collaboration Expansion Agreement (refer to Note 6), except with respect to the 4,000,000 Warrant Shares referenced below that would become exercisable prior to such time upon release of the $10 million that is funded into escrow, depending on the scope of the expansion.. The Warrant may be terminated by us under certain conditions, including if Healios does not make the initial payment required by the Collaboration Expansion Agreement. Under the terms of the Warrant, Healios will have the right to exercise the Warrant and purchase up to an aggregate of 20,000,000 Warrant Shares at the following exercise prices during the following periods: Warrant Shares Tranches Warrant Price per Warrant Share Exercise Period Up to 1,500,000 $2.50 June 1, 2018 through December 31, 2018 Up to 1,500,000 $2.75 September 1, 2018 through March 31, 2019 Up to 1,500,000 $3.00 January 1, 2019 through June 30, 2019 Up to 1,500,000 $3.25 April 1, 2019 through September 30, 2019 Up to 4,000,000 the greater of $1.76 and the Reference Price (which is generally 110% of the average closing price per share of the Company’s common stock for the ten trading days ending on the trading day immediately preceding (and not including) the date the Warrant is exercised) the period beginning on the later of (i) the execution date of the Collaboration Expansion Agreement and (ii) the date that the $10.0 million escrow is released to the Company, through September 1, 2020 Up to 10,000,000, at eight potential time points the greater of $2.50 and the Reference Price June 1, 2018 through August 31, 2018 the greater of $2.75 and the Reference Price September 1, 2018 through November 30, 2018 the greater of $3.00 and the Reference Price December 1, 2018 through February 28, 2019 the greater of $3.25 and the Reference Price March 1, 2019 through May 31, 2019 the greater of $3.50 and the Reference Price June 1, 2019 through August 31, 2019 the greater of $3.75 and the Reference Price September 1, 2019 through November 30, 2019 the greater of $4.00 and the Reference Price December 1, 2019 through February 29, 2020 the greater of $4.25 and the Reference Price March 1, 2020 through September 1, 2020 The Warrant provides for an extension of the term from September 1, 2020 in a limited circumstance. The Warrant also provides that the number of Warrant Shares to be issued thereunder will be limited to the extent that Healios and its affiliates would beneficially own more than 19.9% of our outstanding common stock after giving effect to such exercise and issuance. We evaluated the various terms of the Warrant and concluded that it is appropriately accounted for as equity at inception and $5.3 million was computed as the best estimate of the fair value of the Warrant at the time of issuance. The fair value at inception was computed using a Monte Carlo simulation model that included probability-weighted estimates of potential milestone points in time that could impact the value of the Warrant during its term. The fair value is recorded as additional paid-in Public Equity Offering In February 2017, we completed a public offering generating net proceeds of approximately $20.9 million through the issuance of 22,772,300 shares of common stock at an offering price of $1.01 per share. Equity Purchase Agreement We have in place an equity purchase arrangement with Aspire Capital Fund LLC (“Aspire Capital”), which provides us the ability to sell shares to Aspire Capital from time-to-time, License Agreement and Settlement In October 2017, we entered into an agreement to settle longstanding intellectual property disagreements with a third party. As part of the agreement, we were granted a worldwide, non-exclusive

Financial Instruments

Financial Instruments	3 Months Ended
	Mar. 31, 2018
Investments, All Other Investments [Abstract]
Financial Instruments	9. Financial Instruments Fair Value Measurements We classify the inputs used to measure fair value into the following hierarchy: Level 1 Unadjusted quoted prices in active markets for identical assets or liabilities. Level 2 Unadjusted quoted prices in active markets for similar assets or liabilities, or unadjusted quoted prices for identical or similar assets or liabilities in markets that are not active, or inputs other than quoted prices that are observable for the asset or liability. Level 3 Unobservable inputs for the asset or liability. At March 31, 2018, we had no financial assets or liabilities measured at fair value on a recurring basis. At March 31, 2018, the Warrant was measured at fair value on a nonrecurring basis that represented a Level 3 equity instrument under the hierarchy. Refer to Note 8.

Income Taxes

Income Taxes	3 Months Ended
	Mar. 31, 2018
Income Tax Disclosure [Abstract]
Income Taxes	10. Income Taxes We have U.S. federal net operating loss and research and development tax credit carryforwards, as well as state and city net operating loss carryforwards, which may be used to reduce future taxable income and tax liabilities. We also have foreign net operating loss and tax credit carryforwards, and the foreign net operating loss carryforwards do not expire. All of our deferred tax assets have been fully offset by a valuation allowance due to our cumulative losses. The utilization of net operating loss and tax credit carryforwards generated prior to October 2012 is substantially limited under Section 382 of the Internal Revenue Code of 1986, as amended, as a result of our October 2012 equity offering. We generated U.S. federal net operating loss carryforwards, research and development tax credits, and state and local net operating loss carryforwards since 2012. We will update our analysis under Section 382 prior to using these attributes. In December 2017, the U.S. federal government enacted legislation commonly referred to as the “Tax Cuts and Jobs Act” (the “TCJA”). The TCJA makes widespread changes to the IRC, including, among other items, a reduction in the federal corporate tax rate from 35% to 21%, effective January 1, 2018. The carrying value of our deferred tax assets and liabilities is also determined by the enacted U.S. corporate income tax rate. Consequently, any changes in the U.S. corporate income tax rate will impact the carrying value of our deferred tax assets and liabilities. Our deferred income tax assets, net, have provisionally decreased based on the reduction of the U.S. corporate tax rate and the valuation allowance has had a corresponding decrease. The Deemed Repatriation Transition Tax (“Transition Tax”) is a tax on previously untaxed accumulate and current earnings and profit (“E&P”) of certain of our foreign subsidiaries. To determine the amount of Transition Tax, a company must determine, in addition to other factors, the amount of post-1986 E&P of the relevant foreign subsidiaries as well as the amount of non-U.S. income tax paid on such earnings. We believe we have an overall foreign E&P deficit and, accordingly, have not recorded any provisional Transition Tax obligation. However, we are continuing to gather additional information to finalize our Transition Tax liability. We determined that the provisional calculations will be finalized after the underlying timing differences and foreign earnings and profits are finalized with our 2017 federal tax return filing. Furthermore, we are still analyzing certain aspects of the TCJA and refining our calculations which could potentially affect the measurement of these balances or potentially give rise to new or additional deferred tax amounts. We will consider additional guidance from the U.S. Treasury Department, IRS or other standard-setting bodies. Further adjustments, if any, will be recorded by us during the measurement period in 2018, as permitted by SEC Staff Accounting Bulletin 118, Income Tax Accounting Implications of the Tax Cuts and Jobs Act. No amounts were recorded as of March 31, 2018 for these potential adjustments.

Recently Issued Accounting St16

Recently Issued Accounting Standards (Policies)	3 Months Ended
	Mar. 31, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Recently Issued Accounting Standards	Recently Issued Accounting Standards In February 2016, the Financial Accounting Standards Board (“FASB”) issued ASU 2016-02, right-of-use In May 2017, the FASB issued ASU 2017-09,
Revenue Recognition	Other than for our collaboration with Healios that has remaining deliverables, we had recognized the full amount of license fees under our collaboration agreements as contract revenue under the prior guidance associated with multiple-element arrangements, since the performance periods for our multiple element arrangements have concluded. The events triggering any future contingent milestone payments from these arrangements were determined to be non-substantive
Collaborative Arrangements	Healios 2016 Inception of License Arrangement In 2016, we entered into a license agreement (“Healios Agreement”) with Healios to develop and commercialize MultiStem cell therapy for ischemic stroke in Japan and to provide Healios with access to our proprietary MAPC technology for use in its “organ bud” program, initially for transplantation to treat liver disease or dysfunction. Under the Healios Agreement, Healios obtained a right to expand the scope of the collaboration to include the exclusive rights to develop and commercialize MultiStem for the treatment of certain additional indications in Japan, which include acute respiratory distress syndrome (“ARDS”), and, as addressed herein, plans for an expansion of the collaboration are underway.
Royalties	We may also receive tiered royalties on net product sales, starting in the low double-digits and increasing incrementally into the high teens, depending on net sales levels. If Healios exercised its option to expand the collaboration to include ARDS and another indication in the orthopedic area under the Healios Agreement, we would be entitled to receive a cash payment of $10 million at the time of exercise and royalties from product sales and success-based development, regulatory approval and sales milestones, as well as payments for product supply related to the additional indications covered by the option. Under the proposed expansion plans addressed herein, at a minimum, Healios would exercise its option to include the ARDS field under the Healios Agreement, and the $10 million expansion fee was funded by Healios into an escrow account in March 2018, which is due to be released to us by June 1, 2018. For the “organ bud” product, we are entitled to receive a fractional royalty percentage on net sales of the “organ bud” products and will receive payments for manufactured product supplied to Healios under a manufacturing supply agreement. Additionally, we have a right of first negotiation for commercialization of an “organ bud” product in North America, with such right expiring on certain dates in the future.
Fair Value Measurements	Fair Value Measurements We classify the inputs used to measure fair value into the following hierarchy: Level 1 Unadjusted quoted prices in active markets for identical assets or liabilities. Level 2 Unadjusted quoted prices in active markets for similar assets or liabilities, or unadjusted quoted prices for identical or similar assets or liabilities in markets that are not active, or inputs other than quoted prices that are observable for the asset or liability. Level 3 Unobservable inputs for the asset or liability. At March 31, 2018, we had no financial assets or liabilities measured at fair value on a recurring basis. At March 31, 2018, the Warrant was measured at fair value on a nonrecurring basis that represented a Level 3 equity instrument under the hierarchy. Refer to Note 8. We review and reassess the fair value hierarchy classifications on a quarterly basis. Changes from one quarter to the next related to the observability of inputs in a fair value measurement may result in a reclassification between fair value hierarchy levels. There were no reclassifications for all periods presented.

Revenue Recognition and Adopt17

Revenue Recognition and Adoption of New Accounting Pronouncement (Tables)	3 Months Ended
	Mar. 31, 2018
Revenue from Contract with Customer [Abstract]
Schedule of New Accounting Pronouncements and Changes in Accounting Principles	The components of the cumulative effect of the changes made to our consolidated January 1, 2018 balance sheet for the adoption of Topic 606 were as follows (in thousands): As of December 31, Adjustments Due As of January 1, Assets Accounts receivable - Healios $ 153 $ 30 $ 183 Contractual right to consideration from Healios $ — $ 1,436 $ 1,436 Liabilities Deferred revenue - Healios $ (521 ) $ 521 $ — Advance from Healios $ (134 ) $ (116 ) $ (250 ) Equity Accumulated deficit $ 350,630 $ (1,871 ) $ 348,759 In accordance with the new revenue recognition requirements, the disclosure of the impact of adoption on our condensed consolidated balance sheet and statement of operations for the three months ended March 31, 2018 was as follows (in thousands, except per share data): As of March 31, 2018 As Reported Balances without Effect of Change Assets Contractual right to consideration from Healios $ 1,538 $ — $ 1,538 Liabilities Deferred revenue - Healios $ — $ (259 ) $ 259 Equity Accumulated deficit $ 358,914 $ 360,711 $ (1,797 ) Three months ended March 31, 2018 As Reported Balances without Effect of Change Revenues Contract revenues - Healios $ 348 $ 422 $ (74 ) Net loss $ (10,155 ) $ (10,081 ) $ 74 Net loss per common share Basic and diluted $ (0.08 ) $ (0.08 ) $ —
Summary of Revenues Disaggregated by Recognition at Point in Time and Over Time	The following table presents our contract revenues from Healios disaggregated by recognition at a point in time and over time (in thousands). Three months ended March 31, 2018 Recognized at Point in Time Recognized Over Time Total Contract Revenues - Healios Product supply revenue $ 227 $ — 227 Service revenue — 121 121 Total $ 227 $ 121 $ 348

Net Loss per Share (Tables)

Net Loss per Share (Tables)	3 Months Ended
	Mar. 31, 2018
Earnings Per Share [Abstract]
Instruments Excluded from Calculation of Diluted Net Loss Per Share	The following instruments were excluded from the calculation of diluted net loss per share because their effects would be antidilutive: Three months ended March 31, 2018 2017 Stock-based awards 10,294,613 10,091,837 Warrants – see Note 8 20,000,000 — Total 30,294,613 10,091,837

Background and Basis of Prese19

Background and Basis of Presentation - Additional Information (Detail) $ in Thousands	3 Months Ended
	Mar. 31, 2018USD ($)Segment	Dec. 31, 2017USD ($)	Mar. 31, 2017USD ($)	Dec. 31, 2016USD ($)
Accounting Policies and General Information [Line Items]
Number of business segments | Segment	1
Accumulated deficit	$ (358,914)	$ (350,630)
Cash and cash equivalents	49,673	$ 29,316	$ 31,940	$ 14,753
Healios License Agreement [Member]
Accounting Policies and General Information [Line Items]
Expansion fee in Escrow account	$ 10,000

Recently Issued Accounting St20

Recently Issued Accounting Standards - Additional Information (Detail)	Mar. 31, 2018Facility
Accounting Policies [Abstract]
Number of operating leases facilities that need to be evaluated under the ASU 2016-02	2

Revenue Recognition and Adopt21

Revenue Recognition and Adoption of New Accounting Pronouncement - Additional Information (Detail) - USD ($)	3 Months Ended
	Mar. 31, 2018	Jan. 01, 2018
Revenue recognized that was included in the advance from Healios	$ 0
Accounting Standards Update 2014-09 [Member] | Accumulated Deficit [Member]
Cumulative effect adjustment recognized	$ 1,900,000	$ (1,900,000)

Revenue Recognition and Adopt22

Revenue Recognition and Adoption of New Accounting Pronouncement - Schedule of New Accounting Pronouncements and Changes in Accounting Principles (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Jan. 01, 2018	Dec. 31, 2017
Change in Accounting Estimate [Line Items]
Accounts-receivable - Healios	$ 759			$ 586
Assets
Deferred revenue	250			771
Deferred revenue - Healios	250			771
Equity
Accumulated deficit	(358,914)			(350,630)
Revenues
Contract revenues - Healios	348	$ 28
Net loss	$ (10,155)	$ (5,631)
Net loss per common share
Basic and diluted	$ (0.08)	$ (0.06)
Healios License Agreement [Member]
Change in Accounting Estimate [Line Items]
Accounts-receivable - Healios	$ 132			153
Contractual right to consideration	1,538
Assets
Contractual right to consideration from Healios	1,538
Deferred revenue	0
Deferred revenue - Healios	0
Revenues
Contract revenues - Healios	348
Accounting Standards Update 2014-09 [Member]
Change in Accounting Estimate [Line Items]
Contractual right to consideration			$ 1,900
Assets
Contractual right to consideration from Healios			1,900
Equity
Accumulated deficit			348,759
Accounting Standards Update 2014-09 [Member] | Balances without Adoption of Topic 606 [Member]
Equity
Accumulated deficit	360,711			350,630
Revenues
Contract revenues - Healios	422
Net loss	$ (10,081)
Net loss per common share
Basic and diluted	$ (0.08)
Accounting Standards Update 2014-09 [Member] | Effect of Change [Member]
Equity
Accumulated deficit	$ (1,797)		(1,871)
Revenues
Contract revenues - Healios	(74)
Net loss	$ 74
Net loss per common share
Basic and diluted	$ 0
Accounting Standards Update 2014-09 [Member] | Healios License Agreement [Member]
Change in Accounting Estimate [Line Items]
Accounts-receivable - Healios			183
Contractual right to consideration			1,436
Assets
Contractual right to consideration from Healios			1,436
Deferred revenue			0
Advance from Healios			(250)
Deferred revenue - Healios			0
Accounting Standards Update 2014-09 [Member] | Healios License Agreement [Member] | Balances without Adoption of Topic 606 [Member]
Change in Accounting Estimate [Line Items]
Accounts-receivable - Healios				153
Contractual right to consideration	$ 0			0
Assets
Contractual right to consideration from Healios	0			0
Deferred revenue	(259)			(521)
Advance from Healios				(134)
Deferred revenue - Healios	(259)			$ (521)
Accounting Standards Update 2014-09 [Member] | Healios License Agreement [Member] | Effect of Change [Member]
Change in Accounting Estimate [Line Items]
Accounts-receivable - Healios			30
Contractual right to consideration	1,538		1,436
Assets
Contractual right to consideration from Healios	1,538		1,436
Deferred revenue	259		521
Advance from Healios			(116)
Deferred revenue - Healios	$ 259		$ 521

Revenue Recognition and Adopt23

Revenue Recognition and Adoption of New Accounting Pronouncement - Summary of Revenues Disaggregated by Recognition at Point in Time and Over Time (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Contract Revenues
Total	$ 348	$ 28
Healios License Agreement [Member]
Contract Revenues
Product supply revenue	227
Service revenue	121
Total	348
Recognized at Point in Time [Member] | Healios License Agreement [Member]
Contract Revenues
Product supply revenue	227
Service revenue	0
Total	227
Recognized Over Time [Member] | Healios License Agreement [Member]
Contract Revenues
Product supply revenue	0
Service revenue	121
Total	$ 121

Net Loss per Share - Additional

Net Loss per Share - Additional Information (Detail)	Mar. 31, 2018shares
Healios License Agreement [Member]
Dilutive Securities Included And Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Warrant outstanding	1

Net Loss per Share - Instrument

Net Loss per Share - Instruments Excluded from Calculation of Diluted Net Loss Per Share (Detail) - shares	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total	30,294,613	10,091,837
Stock - Based Awards [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total	10,294,613	10,091,837
Warrants [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total	20,000,000	0

Proceeds from Insurance - Addit

Proceeds from Insurance - Additional Information (Detail) $ in Thousands	3 Months Ended
	Mar. 31, 2018USD ($)
Insurance [Abstract]
Insurance recovery gain recognized	$ 363

Collaborative Arrangements an27

Collaborative Arrangements and Revenue Recognition - Additional Information (Detail)	1 Months Ended	3 Months Ended
	Mar. 31, 2018USD ($)	Mar. 31, 2018USD ($)Milestone	Mar. 31, 2017USD ($)	Jan. 01, 2018USD ($)
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Expansion agreement, payment entitlement	$ 35,000,000
Funded in Escrow account	10,000,000	$ 10,000,000
Reduction incurred in royalties		0	$ 0
Accounting Standards Update 2014-09 [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Contract asset				$ 1,900,000
Accounting Standards Update 2014-09 [Member] | Accumulated Deficit [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Cumulative effect adjustment recognized	1,900,000	1,900,000		(1,900,000)
Healios License Agreement [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Up-front cash payment received		15,000,000
Potential near-term payment received		10,000,000
Expansion fee in Escrow account		10,000,000
License revenue		17,300,000
Contract asset	1,538,000	1,538,000
Collabration agreement contingent payment obligation	$ 25,000,000	$ 25,000,000
Healios License Agreement [Member] | Regulatory and Sales Milestones [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Number of future milestones achieved | Milestone		2
Healios License Agreement [Member] | Accounting Standards Update 2014-09 [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Contract asset				$ 1,436,000
RTI Surgical Inc [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Commercial milestone revenue		$ 0	$ 1,000,000
RTI Surgical Inc [Member] | Maximum [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Cash payment eligible to receive on achievement of certain commercial milestone		$ 34,500,000

Stock-Based Compensation - Addi

Stock-Based Compensation - Additional Information (Detail) $ in Thousands	3 Months Ended
	Mar. 31, 2018USD ($)Planshares	Mar. 31, 2017USD ($)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of incentive plan | Plan	1
Common stock authorized for equity incentive plan	20,035,000
Common stock shares issued	4,487,408
Shares available for issuance	6,435,880
Shares of common stock outstanding	10,294,613
Stock-based compensation expense | $	$ 813	$ 689
Estimated compensation cost of unvested restricted stock | $	$ 6,500
Expired Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock shares issued	241,652
Shares of common stock outstanding	941,249

Stockholders' Equity - Addition

Stockholders' Equity - Additional Information (Detail) - USD ($)	1 Months Ended				3 Months Ended		12 Months Ended
	Mar. 31, 2018	Feb. 28, 2018	Oct. 31, 2017	Feb. 28, 2017	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Class of Stock [Line Items]
Common stock share issued in public offering				22,772,300
Proceeds from common stock issued in public offerings				$ 20,900,000	$ 26,411,000	$ 20,877,000
Common stock offering price				$ 1.01
Payment to acquire intellectual property rights			$ 500,000
Future additional payments to acquire intellectual property rights, each quarter			$ 250,000
Additional shares issuable upon issuance of intellectual property rights			500,000
Aspire Capital [Member]
Class of Stock [Line Items]
Equity purchase agreement, term		3 years
Common stock issued as commitment fees		450,000
Common stock registered for resale		24,700,000
Aspire Capital [Member] | Common Stock [Member]
Class of Stock [Line Items]
Common stock share issued in public offering					3,300,000
Sale of additional shares at an average price					$ 1.67
Maximum [Member] | Aspire Capital [Member]
Class of Stock [Line Items]
Equity purchase agreement, value		$ 100,000,000
Healios License Agreement [Member]
Class of Stock [Line Items]
Common stock share issued in public offering	12,000,000
Warrants issued to purchase additional shares of common stock	20,000,000
Warrants to purchase additional shares of common stock, value	$ 21,100,000
Warrants to purchase additional shares of common stock, price per share	$ 1.76
Minimum ownership percentage in outstanding common stock for two board seats	15.00%
Minimum Ownership Percentage In Outstanding Common Stock for board seat.	5.00%
Maximum ownership percentage that Heallios is allowed to own					19.90%
Fair value of the warrant	$ 5,300,000				$ 5,300,000
2015 Agreement [Member] | Aspire Capital [Member]
Class of Stock [Line Items]
Shares remaining for sale		2,000,000
Intellectual Property [Member]
Class of Stock [Line Items]
Stock issued during period, shares, issued for intellectual property rights			1,000,000
Stock issued during period, amount, issued for intellectual property rights			$ 2,300,000
Intellectual Property [Member] | Accrued License Fees [Member] | Contingent Obligation [Member]
Class of Stock [Line Items]
Stock issued during period, shares, issued for intellectual property rights							500,000
Stock issued during period, amount, issued for intellectual property rights					$ 900,000		$ 900,000

Financial Instruments - Additio

Financial Instruments - Additional Information (Detail)	Mar. 31, 2018USD ($)
Fair Value Disclosures [Abstract]
Financial assets measured at fair value on recurring basis	$ 0
Financial liabilities measured at fair value on recurring basis	$ 0

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail)	3 Months Ended	12 Months Ended
	Mar. 31, 2018	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Federal corporate income tax rate	21.00%	35.00%