Acorda Therapeutics (ACORQ) 10-Q 7 Nov 13 2013 Q3 Quarterly report Financial data

Document_and_Entity_Informatio

Document and Entity Information	9 Months Ended
	Sep. 30, 2013	Oct. 31, 2013
Document and Entity Information	'	'
Entity Registrant Name	'ACORDA THERAPEUTICS INC	'
Entity Central Index Key	'0001008848	'
Document Type	'10-Q	'
Document Period End Date	30-Sep-13	'
Amendment Flag	'false	'
Current Fiscal Year End Date	'--12-31	'
Entity Current Reporting Status	'Yes	'
Entity Filer Category	'Large Accelerated Filer	'
Entity Common Stock, Shares Outstanding	'	41,274,587
Document Fiscal Year Focus	'2013	'
Document Fiscal Period Focus	'Q3	'

Consolidated_Balance_Sheets

Consolidated Balance Sheets (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Current assets:	'	'
Cash and cash equivalents	$46,266	$41,876
Restricted cash	136	380
Short-term investments	246,043	191,949
Trade accounts receivable, net of allowances of $639 and $555, as of September 30, 2013 and December 31, 2012, respectively	24,998	26,327
Prepaid expenses	8,617	6,936
Finished goods inventory held by the Company	25,574	20,176
Finished goods inventory held by others	671	781
Deferred tax asset	28,940	35,091
Other current assets	6,558	9,547
Total current assets	387,803	333,063
Long-term investments	57,069	99,363
Property and equipment, net of accumulated depreciation	17,752	16,706
Deferred tax asset	101,725	101,636
Intangible assets, net of accumulated amortization	17,590	9,319
Non-current portion of deferred cost of license revenue	4,332	4,808
Other assets	376	437
Total assets	586,647	565,332
Current liabilities:	'	'
Accounts payable	15,907	22,503
Accrued expenses and other current liabilities	29,920	35,758
Deferred product revenue-Zanaflex	31,221	29,275
Current portion of deferred license revenue	9,057	9,057
Current portion of revenue interest liability	1,009	1,134
Current portion of convertible notes payable	1,144	1,144
Total current liabilities	88,258	98,871
Non-current portion of deferred license revenue	61,892	68,685
Put/call liability	'	329
Non-current portion of revenue interest liability	659	1,111
Non-current portion of convertible notes payable	3,196	4,244
Other non-current liabilities	6,251	6,171
Commitments and contingencies	'	'
Stockholders' equity:	'	'
Common stock, $0.001 par value. Authorized 80,000,000 shares at September 30, 2013 and December 31, 2012; issued and outstanding 40,623,609 and 39,804,493 shares, including those held in treasury, as of September 30, 2013 and December 31, 2012, respectively	41	40
Treasury stock at cost (12,420 shares at September 30, 2013 and December 31, 2012)	-329	-329
Additional paid-in capital	670,855	640,671
Accumulated deficit	-244,274	-254,523
Accumulated other comprehensive income	98	62
Total stockholders' equity	426,391	385,921
Total liabilities and stockholders' equity	$586,647	$565,332

Consolidated_Balance_Sheets_Pa

Consolidated Balance Sheets (Parenthetical) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, except Share data, unless otherwise specified
Consolidated Balance Sheets	'	'
Trade accounts receivable, allowances (in dollars)	$639	$555
Common stock, par value (in dollars per share)	$0.00	$0.00
Common stock, Authorized shares	80,000,000	80,000,000
Common stock, issued shares	40,623,609	39,804,493
Common stock, outstanding shares	40,623,609	39,804,493
Treasury stock, shares	12,420	12,420

Consolidated_Statements_of_Ope

Consolidated Statements of Operations (USD $)	3 Months Ended		9 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Revenues:	'	'	'	'
Net product revenues	$79,760	$72,206	$223,969	$206,992
Royalty revenues	2,895	2,967	13,076	10,557
License revenue	2,264	2,264	6,793	6,793
Total net revenues	84,919	77,437	243,838	224,342
Costs and expenses:	'	'	'	'
Cost of sales	17,213	14,761	47,631	40,802
Cost of license revenue	159	159	476	476
Research and development	13,839	12,031	39,575	35,690
Selling, general and administrative	42,336	40,121	138,538	123,096
Total operating expenses	73,547	67,072	226,220	200,064
Operating income	11,372	10,365	17,618	24,278
Other expense (net):	'	'	'	'
Interest and amortization of debt discount expense	-544	-373	-1,884	-1,501
Interest income	162	135	501	393
Total other expense (net)	-382	-238	-1,383	-1,108
Income before taxes	10,990	10,127	16,235	23,170
Provision for income taxes	-3,513	-533	-5,985	-1,185
Net income	$7,477	$9,594	$10,250	$21,985
Net income per share-basic (in dollars per share)	$0.19	$0.24	$0.26	$0.56
Net income per share-diluted (in dollars per share)	$0.18	$0.24	$0.25	$0.55
Weighted average common shares outstanding used in computing net income per share-basic (in shares)	40,315	39,463	40,037	39,412
Weighted average common shares outstanding used in computing net income per share-diluted (in shares)	41,996	40,159	41,541	40,222

Consolidated_Statements_of_Com

Consolidated Statements of Comprehensive Income (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Consolidated Statements of Comprehensive Income	'	'	'	'
Net income	$7,477	$9,594	$10,250	$21,985
Other comprehensive income (loss):	'	'	'	'
Unrealized losses on available for sale securities, net of tax	44	108	36	3
Other comprehensive income (loss), net of tax	44	108	36	3
Comprehensive income	$7,521	$9,702	$10,286	$21,988

Consolidated_Statements_of_Cas

Consolidated Statements of Cash Flows (USD $)	9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012
Cash flows from operating activities:	'	'
Net income	$10,250	$21,985
Adjustments to reconcile net income to net cash provided by operating activities:	'	'
Share-based compensation expense	18,001	15,349
Amortization of net premiums and discounts on investments	1,774	3,700
Amortization of revenue interest issuance cost	37	58
Depreciation and amortization expense	4,623	3,050
Gain on put/call liability	-329	-476
Deferred tax provision	6,063	'
Changes in assets and liabilities:	'	'
Decrease (increase) in accounts receivable	1,328	-399
Decrease (increase) in prepaid expenses and other current assets	1,308	-4,140
(Increase) decrease in inventory held by the Company	-5,308	8,850
Decrease in inventory held by others	111	292
Decrease in non-current portion of deferred cost of license revenue	476	476
Decrease (increase) in other assets	25	-88
Decrease in accounts payable, accrued expenses, other current liabilities	-13,481	-4,854
Increase in revenue interest liability interest payable	92	495
Decrease in non-current portion of deferred license revenue	-6,793	-6,793
Decrease in other non-current liabilities	-272	-160
Increase (decrease) in deferred product revenue-Zanaflex	1,946	-1,800
Decrease (increase) in restricted cash	244	-167
Net cash provided by operating activities	20,095	35,378
Cash flows from investing activities:	'	'
Purchases of property and equipment	-3,663	-9,167
Purchases of intangible assets	-2,518	-1,865
Acquisition	-7,499	'
Purchases of investments	-128,038	-232,633
Proceeds from maturities of investments	114,500	188,250
Net cash used in investing activities	-27,218	-55,415
Cash flows from financing activities:	'	'
Proceeds from issuance of common stock and option exercises	12,183	2,921
Repayments of revenue interest liability	-670	-812
Net cash provided by financing activities	11,513	2,109
Net increase (decrease) in cash and cash equivalents	4,390	-17,928
Cash and cash equivalents at beginning of period	41,876	57,954
Cash and cash equivalents at end of period	46,266	40,026
Supplemental disclosure:	'	'
Cash paid for interest	1,695	881
Cash paid for taxes	$1,742	$1,097

Organization_and_Business_Acti

Organization and Business Activities	9 Months Ended
	Sep. 30, 2013
Organization and Business Activities	'
Organization and Business Activities	'
	(1) Organization and Business Activities
	Acorda Therapeutics, Inc. (“Acorda” or the “Company”) is a commercial stage biopharmaceutical company dedicated to the identification, development and commercialization of novel therapies that improve neurological function in people with multiple sclerosis (MS), spinal cord injury (SCI) and other disorders of the central nervous system.
	The management of the Company is responsible for the accompanying unaudited interim consolidated financial statements and the related information included in the notes to the consolidated financial statements. In the opinion of management, the unaudited interim consolidated financial statements reflect all adjustments, including normal recurring adjustments necessary for the fair presentation of the Company’s financial position and results of operations and cash flows for the periods presented. Results of operations for interim periods are not necessarily indicative of the results to be expected for the entire year.
	These unaudited interim consolidated financial statements should be read in conjunction with the audited consolidated financial statements of the Company as of and for the year ended December 31, 2012 included in the Company’s Annual Report on Form 10-K for such year, as filed with the Securities and Exchange Commission (the SEC).

Summary_of_Significant_Account

Summary of Significant Accounting Policies	9 Months Ended
	Sep. 30, 2013
Summary of Significant Accounting Policies	'
Summary of Significant Accounting Policies	'
	(2) Summary of Significant Accounting Policies
	Principles of Consolidation
	The accompanying consolidated financial statements are prepared in accordance with accounting principles generally accepted in the United States of America and include the results of operations of the Company and its majority owned subsidiaries. All intercompany accounts and transactions have been eliminated in consolidation.
	Use of Estimates
	The preparation of the consolidated financial statements requires management of the Company to make a number of estimates and assumptions relating to the reported amount of assets and liabilities and the disclosure of contingent assets and liabilities at the date of the consolidated financial statements and the reported amounts of revenues and expenses during the period. Significant items subject to such estimates and assumptions include share-based compensation accounting, which are largely dependent on the fair value of the Company’s equity securities. In addition, the Company recognizes Zanaflex revenue based on estimated prescriptions filled. The Company adjusts its Zanaflex inventory value based on an estimate of inventory that may be returned. Actual results could differ from those estimates.
	Investments
	Both short-term and long-term investments consist of US Treasury bonds. The Company classifies marketable securities available to fund current operations as short-term investments in current assets on its consolidated balance sheets. Marketable securities are classified as long-term investments in long-term assets on the consolidated balance sheets if the Company has the ability and intent to hold them and such holding period is longer than one year. The Company classifies its short-term and long-term investments as available-for-sale. Available-for-sale securities are recorded at fair value of the investments based on quoted market prices.
	Unrealized holding gains and losses on available-for-sale securities, which are determined to be temporary, are excluded from earnings and are reported as a separate component of accumulated other comprehensive income (loss).
	Premiums and discounts on investments are amortized over the life of the related available-for-sale security as an adjustment to yield using the effective-interest method. Dividend and interest income are recognized when earned. Amortized premiums and discounts, dividend and interest income and realized gains and losses are included in interest income.
	Accumulated Other Comprehensive Income
	The Company’s accumulated other comprehensive income is comprised of gains and losses on available for sale securities and is recorded and presented net of income tax.
	Revenue Recognition
	Ampyra
	Ampyra is available only through a network of specialty pharmacy providers that provide the medication to patients by mail; Kaiser Permanente, which distributes Ampyra to patients through a closed network of on-site pharmacies; and ASD Specialty Healthcare, Inc. (an AmerisourceBergen affiliate), which is the exclusive specialty pharmacy distributor for Ampyra to the U.S. Bureau of Prisons and the U.S. Department of Veterans Affairs (VA). Ampyra is not available in retail pharmacies. The Company does not recognize revenue from product sales until there is persuasive evidence of an arrangement, delivery has occurred, the price is fixed and determinable, the buyer is obligated to pay the Company, the obligation to pay is not contingent on resale of the product, the buyer has economic substance apart from the Company, the Company has no obligation to bring about the sale of the product, and the amount of returns can be reasonably estimated and collectability is reasonably assured. The Company recognizes product sales of Ampyra following shipment of product to a network of specialty pharmacy providers, Kaiser Permanente, and the specialty distributor to the VA. The specialty pharmacy providers, Kaiser Permanente, and the specialty distributor to the VA are contractually obligated to hold no more than an agreed number of days of inventory, ranging from 10 to 30 days.
	The Company’s net revenues represent total revenues less allowances for customer credits, including estimated rebates, discounts and returns. These allowances are recorded for cash consideration given by a vendor to a customer that is presumed to be a reduction of the selling prices of the vendor’s products or services and, therefore, are characterized as a reduction of revenue. At the time product is shipped to specialty pharmacies, Kaiser Permanente and the specialty distributor to the VA, an adjustment is recorded for estimated rebates, discounts and returns. These allowances are established by management as its best estimate based on available information and will be adjusted to reflect known changes in the factors that impact such allowances. Allowances for rebates, discounts and returns are established based on the contractual terms with customers, historical trends, communications with customers and the levels of inventory remaining in the distribution channel, as well as expectations about the market for the product and anticipated introduction of competitive products.  Product shipping and handling costs are included in cost of sales.  Effective December 1, 2012, the Company no longer accepts returns of Ampyra with the exception of product damages that occur during shipping.
	Zanaflex
	The Company applies the revenue recognition guidance in Accounting Standards Codification (ASC) 605-15-25, which among other criteria requires that future returns can be reasonably estimated in order to recognize revenue. The amount of future tablet returns is uncertain due to generic competition and customer conversion to Zanaflex Capsules. The Company has accumulated some sales history with Zanaflex Capsules; however, due to existing and potential generic competition and customer conversion from Zanaflex tablets to Zanaflex Capsules, we do not believe we can reasonably determine a return rate at this time. As a result, the Company accounts for these product shipments using a deferred revenue recognition model. Under the deferred revenue model, the Company does not recognize revenue upon product shipment. For these product shipments, the Company invoices the wholesaler, records deferred revenue at gross invoice sales price, and classifies the cost basis of the product held by the wholesaler as a component of inventory. The Company recognizes revenue when prescribed to the end-user, on a first-in first-out (FIFO) basis. The Company’s revenue to be recognized is based on (1) the estimated prescription demand, based on pharmacy sales for its products; and (2) the Company’s analysis of third-party information, including third-party market research data. The Company’s estimates are subject to the inherent limitations of estimates that rely on third-party data, as certain third-party information is itself in the form of estimates, and reflect other limitations. The Company’s sales and revenue recognition reflects the Company’s estimates of actual product prescribed to the end-user. The Company expects to be able to apply a more traditional revenue recognition policy such that revenue is recognized following shipment to the customer when it believes it has sufficient data to develop reasonable estimates of expected returns based upon historical returns and greater certainty regarding generic competition.
	The Company’s net revenues represent total revenues less allowances for customer credits, including estimated discounts, rebates, and chargebacks. These allowances are recorded for cash consideration given by a vendor to a customer that is presumed to be a reduction of the selling prices of the vendor’s products or services and, therefore, should be characterized as a reduction of revenue when recognized in the vendor’s statement of operations. Adjustments are recorded for estimated chargebacks, rebates, and discounts. These allowances are established by management as its best estimate based on available information and are adjusted to reflect known changes in the factors that impact such allowances. Allowances for chargebacks, rebates and discounts are established based on the contractual terms with customers, analysis of historical levels of discounts, chargebacks and rebates, communications with customers and the levels of inventory remaining in the distribution channel, as well as expectations about the market for each product and anticipated introduction of competitive products. In addition, the Company records a charge to cost of goods sold for the cost basis of the estimated product returns the Company believes may ultimately be realized at the time of product shipment to wholesalers. The Company has recognized this charge at the date of shipment since it is probable that it will receive a level of returned products; upon the return of such product it will be unable to resell the product considering its expiration dating; and it can reasonably estimate a range of returns. This charge represents the cost basis for the low end of the range of the Company’s estimated returns. Product shipping and handling costs are included in cost of sales.
	Qutenza
	Qutenza is sold through a specialty distributor, who sells Qutenza to physician offices, hospitals, clinics, and specialty pharmacies. The Company does not recognize revenue from product sales until there is persuasive evidence of an arrangement, delivery has occurred, the price is fixed and determinable, the buyer is obligated to pay the Company, the obligation to pay is not contingent on resale of the product, the buyer has economic substance apart from the Company, the Company has no obligation to bring about the sale of the product, and the amount of returns can be reasonably estimated and collectability is reasonably assured. This means that, for Qutenza, the Company recognizes product sales following shipment of product to its specialty distributor.
	The Company’s net revenues represent total revenues less allowances for customer credits, including estimated rebates and returns. These allowances are recorded for cash consideration given by a vendor to a customer that is presumed to be a reduction of the selling prices of the vendor’s products or services and, therefore, are characterized as a reduction of revenue. At the time product is shipped, an adjustment is recorded for estimated rebates and returns. These allowances are established by management as its best estimate based on available information and will be adjusted to reflect known changes in the factors that impact such allowances. Allowances for rebates and returns are established based on the contractual terms with customers, historical trends, as well as expectations about the market for the product and anticipated introduction of competitive products.  Product shipping and handling costs are included in cost of sales.
	Milestones and royalties
	In order to determine the revenue recognition for contingent milestones, the Company evaluates the contingent milestones using the criteria as provided by the Financial Accounting Standards Boards (FASB) guidance on the milestone method of revenue recognition. At the inception of a collaboration agreement the Company evaluates if payments are substantive.  The criteria requires that (i) the Company determines if the milestone is commensurate with either its performance to achieve the milestone or the enhancement of value resulting from the Company’s activities to achieve the milestone, (ii) the milestone be related to past performance, and (iii) the milestone be reasonable relative to all deliverable and payment terms of the collaboration arrangement.  If these criteria are met then the contingent milestones can be considered substantive milestones and will be recognized as revenue in the period that the milestone is achieved. Royalties are recognized as earned in accordance with the terms of various research and collaboration agreements.
	In-Process Research and Development
	The cost of in-process research and development (IPR&D) acquired directly in a transaction other than a business combination is capitalized if the projects will be further developed or have an alternative future use; otherwise they are expensed. The fair values of IPR&D projects acquired in business combinations are capitalized. Several methods may be used to determine the estimated fair value of the IPR&D acquired in a business combination. The Company utilizes the “income method,” and uses estimated future net cash flows that are derived from projected sales revenues and estimated costs. These projections are based on factors such as relevant market size, patent protection, historical pricing and expected industry trends. The estimated future net cash flows are then discounted to the present value using an appropriate discount rate. These assets are treated as indefinite-lived intangible assets until completion or abandonment of the projects, at which time the assets are amortized over the remaining useful life or written off, as appropriate. IPR&D intangible assets which are determined to have had a drop in their fair value are adjusted downward and an expense recognized on the statement of operations. These are tested at least annually or sooner when a triggering event occurs that could indicate a potential impairment.
	Collaborations
	The Company recognizes collaboration revenues and expenses by analyzing each element of the agreement to determine if it shall be accounted for as a separate element or single unit of accounting. If an element shall be treated separately for revenue recognition purposes, the revenue recognition principles most appropriate for that element are applied to determine when revenue shall be recognized. If an element shall not be treated separately for revenue recognition purposes, the revenue recognition principles most appropriate for the bundled group of elements are applied to determine when revenue shall be recognized. Payments received in excess of revenues recognized are recorded as deferred revenue until such time as the revenue recognition criteria have been met.
	Concentration of Credit Risk
	The Company’s principal direct customers as of September 30, 2013 were a network of specialty pharmacies, Kaiser Permanente, and the specialty distributor to the VA for Ampyra, wholesale pharmaceutical distributors for Zanaflex Capsules and Zanaflex tablets, and a specialty distributor for Qutenza. The Company periodically assesses the financial strength of these customers and establishes allowances for anticipated losses, if necessary. Four customers individually accounted for more than 10% of the Company’s revenue in 2013 and 2012, and three customers in 2011. Four customers individually accounted for more than 10% of the Company’s accounts receivable as of September 30, 2013 and December 31, 2012. The Company’s net product revenues are generated in the United States.
	Segment and Geographic Information
	The Company is managed and operated as one business which is focused on the identification, development and commercialization of novel therapies that improve neurological function in people with MS, SCI and other disorders of the central nervous system. The entire business is managed by a single management team that reports to the chief executive officer. The Company does not operate separate lines of business with respect to any of its products or product candidates and the Company does not prepare discrete financial information with respect to separate products or product candidates or by location.  Accordingly, the Company views its business as one reportable operating segment. Net product revenues reported to date are derived from the sales of Ampyra, Zanaflex and Qutenza in the United States.
	Subsequent Events
	Subsequent events are defined as those events or transactions that occur after the balance sheet date, but before the financial statements are filed with the Securities and Exchange Commission. The Company completed an evaluation of the impact of any subsequent events through the date these financial statements were issued, and determined there were no subsequent events requiring disclosure in or requiring adjustment to these financial statements.
	Recent Accounting Pronouncements
	In February 2013, the FASB amended its guidance to require an entity to present the effect of certain significant reclassifications out of accumulated other comprehensive income on the respective line items in net income. The new accounting guidance does not change the items that must be reported in other comprehensive income or when an item of other comprehensive income must be reclassified to net income. The guidance is effective prospectively for fiscal years beginning after December 15, 2012. The Company adopted these new provisions for the quarter beginning January 1, 2013. As the guidance requires additional presentation only, there was no impact to the Company’s consolidated results of operations or financial position.
	In July 2013, the FASB issued ASU 2013-11, Presentation of an Unrecognized Tax Benefit When a Net Operating Loss Carryforward, a Similar Tax Loss, or a Tax Credit Carryforward Exists, (ASU 2013-11), an amendment to ASC 740, Income Taxes. ASU 2013-11 clarifies that an unrecognized tax benefit, or a portion of an unrecognized tax benefit, should be presented in the financial statements as a reduction to a deferred tax asset for a net operating loss carryforward, a similar tax loss, or a tax credit carryforward if such settlement is required or expected in the event the uncertain tax benefit is disallowed. In situations where a net operating loss carryforward, a similar tax loss, or a tax credit carryforward is not available at the reporting date under the tax law of the applicable jurisdiction or the tax law of the jurisdiction does not require, and the entity does not intend to use, the deferred tax asset for such purpose, the unrecognized tax benefit should be presented in the financial statements as a liability and should not be netted with the deferred tax asset. The amendments in ASU 2013-11 are effective for fiscal years, and interim periods within those years, beginning after December 15, 2013. Early adoption is permitted. The amendments should be applied prospectively to all unrecognized tax benefits that exist at the effective date. Retrospective application is permitted. The Company is currently evaluating the impact that adoption will have on the determination or reporting of its financial results.

Acquisition

Acquisition	9 Months Ended
	Sep. 30, 2013
Acquisition	'
Acquisition	'
	(3) Acquisition
	NeurogesX Acquisition
	On July 8, 2013, Acorda acquired certain assets from NeurogesX, Inc. (“NeurogesX”), including two neuropathic pain management assets: Qutenza and NP-1998. Qutenza is approved by the FDA for the management of neuropathic pain associated with postherpetic neuralgia. NP-1998 is a Phase 3 ready prescription strength capsaicin topical solution being assessed for the treatment of neuropathic pain. NP-1998 was previously referred to as NGX-1998. Prior to the acquisition, NeurogesX was a specialty pharmaceutical company focused on developing and commercializing a portfolio of novel non-opioid pain management therapies headquartered in San Mateo, CA. Acquisition-related costs during the nine-month period ended September 30, 2013 of approximately $1.0 million for advisory, legal, regulatory and valuation costs incurred in connection with the NeurogesX acquisition have been expensed in selling, general and administrative expenses.
	Astellas Pharma Europe Ltd. (“Astellas”) has exclusive commercialization rights for Qutenza in the European Economic Area including the 28 countries of the European Union, Iceland, Norway, and Liechtenstein as well as Switzerland, certain countries in Eastern Europe, the Middle East and Africa. Astellas also has an option to develop NP-1998 in those same territories. Astellas is currently conducting clinical trials of Qutenza including a Phase 3 trial to assess its use in the treatment of pain associated with painful diabetic neuropathy (“PDN”). Under the terms of the agreement, Acorda will have rights to review data from that trial, and the companies may also collaborate and/or share costs of future clinical trials.
	In consideration for the acquisition of assets pursuant to the Asset Purchase Agreement, Acorda paid NeurogesX $7.5 million in cash and will pay up to an additional $5.0 million of post-closing milestone payments (“Milestone Payments”), as follows:
	·                                          $2.0 million upon the approval for sale of an NP-1998 liquid formulation product in the United States for the cutaneous treatment of PDN in humans, if FDA approval is obtained prior to December 31, 2016; and
	·                                          $3.0 million if net sales of an NP-1998 approved product in Acorda’s territory reach $100,000,000 during the first 12 months that such product is sold in Acorda’s territory, commencing with the first date that such product is commercially available for purchase anywhere in Acorda’s territory. Acorda’s territory consists of all territories worldwide other than those jurisdictions covered by the Astellas Agreement, which generally comprise countries in Europe, Africa and the Middle East .
	There is no assurance that any of the conditions for the Milestone Payments will be met. Refer to Note 7 — Fair Value Measurements for more information on the contingent consideration liability.
	Total preliminary estimated purchase price is summarized as follows:
	(in thousands)
	Cash paid to NeurogesX shareholders and its creditors	$	7,499
	Fair value of contingent liabilities	205
	Total preliminary estimated purchase price	$	7,704
	The preliminary allocation of the purchase price to the fair value of assets acquired reflects the estimated fair values of NeurogesX’s assets as of the acquisition date. In accordance with the acquisition method of accounting, the Company allocated the acquisition cost for the NeurogesX transaction to the underlying assets acquired by the Company, based upon the estimated fair values of those assets at the date of acquisition and will classify the fair value of acquired IPR&D as an indefinite-lived asset until the successful completion or abandonment of the associated research and development efforts. The Company accounted for the transaction as a business combination and is in the process of finalizing the valuation of intangible assets and fair value of the contingent purchase price. As a result, the preliminary measurements of intangible assets and certain tangible assets described below are subject to change.  The results of NeurogesX’s operations have been included in the consolidated statements of operations from the date of acquisition.
	The following table presents the preliminary allocation of purchase price to assets acquired:
	(in thousands)
	Inventory	$	90
	Equipment	173
	Identifiable intangible assets:
	Developed technology - Qutenza	450
	In-process research and development – NP-1998	6,991
	Fair value of acquired assets	7,704
	Aggregate purchase price	7,704
	Goodwill	$	—
	Pro Forma Financial Information (Unaudited)
	The following table summarizes certain supplemental pro forma financial information which was prepared as if the acquisition of NeurogesX had occurred as of January 1, 2012.  The unaudited pro forma financial information was prepared for comparative purposes only and is not necessarily indicative of what would have occurred had the acquisition been made at that time or of results which may occur in the future.
		Three-month period ended				Three-month period ended
		September 30, 2013				September 30, 2012
	(In thousands)	Reported		Pro Forma		Reported		Pro Forma
	Net revenues	$	84,919	$	84,919	$	77,437	$	80,285
	Net income	7,477		7,477		9,594		3,595
		Nine-month period ended				Nine-month period ended
		September 30, 2013				September 30, 2012
	(In thousands)	Reported		Pro Forma		Reported		Pro Forma
	Net revenues	$	243,838	$	249,122	$	224,342	$	232,887
	Net income	10,250		6,751		21,985		3,988
	The pro forma financial information includes a non-recurring pro forma adjustment of $1.7 million for the nine-month period ended September 30, 2013, related to transaction costs incurred by the Company and NeurogesX as part of the acquisition. Revenue and earnings from the acquired business since the acquisition date included in our consolidated statements of operations were not material.

Sharebased_Compensation

Share-based Compensation	9 Months Ended
	Sep. 30, 2013
Share-based Compensation	'
Share-based Compensation	'
	(4) Share-based Compensation
	During the three-month periods ended September 30, 2013 and 2012, the Company recognized share-based compensation expense of $6.5 million and $5.6 million, respectively. During the nine-month periods ended September 30, 2013 and 2012, the Company recognized share-based compensation expense of $18.0 million and $15.3 million, respectively. Activity in options and restricted stock during the nine-month period ended September 30, 2013 and related balances outstanding as of that date are reflected below. The weighted average fair value per share of options granted to employees for the three-month periods ended September 30, 2013 and 2012 were approximately $18.02 and $13.00, respectively. The weighted average fair value per share of options granted to employees for the nine-month periods ended September 30, 2013 and 2012 were approximately $15.76 and $13.74, respectively.
	The following table summarizes share-based compensation expense included within the consolidated statements of operations:
		For the three-month						For the nine-month
		period ended September 30,						period ended September 30,
	(In millions)	2013			2012			2013			2012
	Research and development	$	1.5		$	1.4		$	4.2		$	3.7
	Selling, general and administrative	5			4.2			13.8			11.6
	Total	$	6.5		$	5.6		$	18		$	15.3
	A summary of share-based compensation activity for the nine-month period ended September 30, 2013 is presented below:
	Stock Option Activity
		Number of Shares		Weighted Average			Weighted Average		Intrinsic Value
		(In thousands)		Exercise Price			Remaining		(In thousands)
							Contractual
							Term
	Balance at January 1, 2013	5,667		$	22.3
	Granted	1,600		31.05
	Cancelled	(165	)	27.48
	Exercised	(797	)	15.29
	Balance at September 30, 2013	6,305		$	25.27		7		$	56,639
	Vested and expected to vest at September 30, 2013	6,237		$	25.22		7		$	56,316
	Vested and exercisable at September 30, 2013	3,675		$	22.97		5.7		$	41,346
	Restricted Stock Activity
	(In thousands)	Number of Shares
	Restricted Stock
	Nonvested at January 1, 2013	458
	Granted	211
	Vested	(22	)
	Forfeited	(30	)
	Nonvested at September 30, 2013	617
	Unrecognized compensation cost for unvested stock options and restricted stock awards as of September 30, 2013 totaled $46.6 million and is expected to be recognized over a weighted average period of approximately 2.6 years.

Earnings_Per_Share

Earnings Per Share	9 Months Ended
	Sep. 30, 2013
Earnings Per Share	'
Earnings Per Share	'
	(5) Earnings Per Share
	The following table sets forth the computation of basic and diluted earnings per share for the three and nine-month periods ended September 30, 2013 and 2012:
	(In thousands, except per share data)	Three-month			Three-month		Nine-month		Nine-month
		period ended			period ended		period ended		period ended
		September 30, 2013			September 30, 2012		September 30, 2013		September 30, 2012
	Basic and diluted
	Net income	$	7,477		$	9,594	$	10,250	$	21,985
	Weighted average common shares outstanding used in computing net income per share—basic	40,315			39,463		40,037		39,412
	Plus: net effect of dilutive stock options and restricted common shares	1,681			696		1,504		810
	Weighted average common shares outstanding used in computing net income per share—diluted	41,996			40,159		41,541		40,222
	Net income per share—basic	$	0.19		$	0.24	$	0.26	$	0.56
	Net income per share—diluted	$	0.18		$	0.24	$	0.25	$	0.55
	The difference between basic and diluted shares is that diluted shares include the dilutive effect of the assumed exercise of outstanding securities. The Company’s stock options and unvested shares of restricted common stock could have the most significant impact on diluted shares.
	Securities that could potentially be dilutive are excluded from the computation of diluted earnings per share when a loss from continuing operations exists or when the exercise price exceeds the average closing price of the Company’s common stock during the period, because their inclusion would result in an anti-dilutive effect on per share amounts.
	The following amounts were not included in the calculation of net income per diluted share because their effects were anti-dilutive:
	(In thousands)	Three-month		Three-month		Nine-month	Nine-month
		period ended		period ended		period ended	period ended
		September 30,		September 30,		September 30,	September 30,
		2013		2012		2013	2012
	Denominator
	Stock options and restricted common shares	1,558		3,910		2,786	3,831
	Convertible note	39		48		39	48

Income_Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2013
Income Taxes	'
Income Taxes	'
	(6) Income Taxes
	For the three-month periods ended September 30, 2013 and 2012, the Company recorded a $3.5 million and $533,000 provision for income taxes, respectively, based upon its estimated tax liability for the year. The provision for income taxes is based on federal, state and Puerto Rico income taxes. The effective income tax rates for the Company for the three-month periods ended September 30, 2013 and 2012 were 32.0% and 5.2%, respectively.  For the nine-month periods ended September 30, 2013 and 2012, the Company recorded a $5.9 million and $1.2 million provision for income taxes, respectively, based upon its estimated tax liability for the year. The provision for income taxes is based on federal, state and Puerto Rico income taxes. The effective income tax rates for the Company for the nine-month periods ended September 30, 2013 and 2012 were 36.8% and 5.1%, respectively. As a result of the January 2013 extension of the Federal research and development tax credit retroactive to January 2012 the Company recorded a benefit of $1.2 million for the estimated 2012 credit. During the nine-month period ended September 30, 2013 the Company also settled an IRS examination of their corporate income tax returns for years ending December 31, 2009 through December 31, 2011.  The impact of the settlement partially offset the benefit recorded for the research and development tax credit.
	The Company continues to evaluate the realizability of its deferred tax assets and liabilities on a periodic basis and will adjust such amounts in light of changing facts and circumstances including, but not limited to, future projections of taxable income, tax legislation, rulings by relevant tax authorities, the progress of ongoing tax audits and the regulatory approval of products currently under development. Any changes to the valuation allowance or deferred tax assets in the future would impact the Company’s income taxes.

Fair_Value_Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2013
Fair Value Measurements	'
Fair Value Measurements	'
	(7) Fair Value Measurements
	The following table presents information about the Company’s assets and liabilities measured at fair value on a recurring basis as of September 30, 2013 and indicates the fair value hierarchy of the valuation techniques utilized to determine such fair value. In general, fair values determined by Level 1 inputs utilize quoted prices (unadjusted) in active markets for identical assets or liabilities. Fair values determined by Level 2 inputs utilize data points that are observable, such as quoted prices, interest rates and yield curves. Fair values determined by Level 3 inputs utilize unobservable data points for the asset or liability. The Company’s Level 1 assets consist of time deposits and investments in a Treasury money market fund and the Company’s Level 2 assets consist of high-quality government bonds and are valued using market prices on the active markets.  Level 1 instrument valuations are obtained from real-time quotes for transactions in active exchange markets involving identical assets and Level 2 assets are valued using quoted prices for similar assets and liabilities in active markets or other market observable inputs such as interest rates and yield curves. The Company’s Level 3 liabilities represent our put/call liability related to the Paul Royalty Fund (PRF) transaction and contingent consideration related to the NeurogesX acquisition. No changes in valuation techniques or inputs occurred during the nine months ended September 30, 2013.
	(In thousands)	Level 1		Level 2		Level 3
	September 30, 2013
	Assets Carried at Fair Value:
	Cash equivalents	$	38,381	$	—	$	—
	Short-term investments	—		246,043		—
	Long-term investments	—		57,069		—
	Liabilities Carried at Fair Value:
	Put/call liability	—		—		—
	Contingent purchase price	—		—		205
	December 31, 2012
	Assets Carried at Fair Value:
	Cash equivalents	$	27,932	$	—	$	—
	Short-term investments	—		191,949		—
	Long-term investments	—		99,363		—
	Liabilities Carried at Fair Value:
	Put/call liability	—		—		329
	Contingent purchase price	—		—		—
	The following tables present additional information about assets and/or liabilities measured at fair value on a recurring basis and for which the Company utilizes Level 3 inputs to determine fair value.
	Put/call liability
	(In thousands)	Three-month		Three-month		Nine-month			Nine-month
		period ended		period ended		period ended			period ended
		September 30,		September 30,		September 30,			September 30,
		2013		2012		2013			2012
	Put/call liability:
	Balance, beginning of period	$	—	$	511	$	329		$	1,030
	Total realized and unrealized gains included in selling, general and administrative expenses:	—		43		(329		)	(476		)
	Balance, end of period	$	—	$	554	$	—		$	554
	The Company estimates the fair value of its put/call liability using a discounted cash flow valuation technique. Using this approach, historical and expected future cash flows are calculated over the expected life of the PRF agreement, are discounted, and then exercise scenario probabilities are applied. Some of the more significant assumptions made in the valuation include (i) the estimated Zanaflex revenue forecast and (ii) the likelihood of put/call exercise trigger events such as bankruptcy and change of control. The valuation is performed periodically when the significant assumptions change.  Realized gains and losses are included in selling, general and administrative expenses.
	The put/call liability has been classified as a Level 3 liability as its valuation requires substantial judgment and estimation of factors that are not currently observable in the market due to the lack of trading in the security. If different assumptions were used for the various inputs to the valuation approach including, but not limited to, assumptions involving the estimated Zanaflex revenue forecast and the likelihood of trigger events, the estimated fair value could be significantly higher or lower than the fair value we determined. The Company may be required to record losses in future periods, which may be significant.
	Contingent purchase price
	(In thousands)	Three-month		Three-month		Nine-month			Nine-month
		period ended		period ended		period ended			period ended
		September 30,		September 30,		September 30,			September 30,
		2013		2012		2013			2012
	Contingent purchase price:
	Balance, beginning of period	$	—	$	—	$	—		$	—
	Fair value of contingent purchase price as of July 8, 2013	205		—		205			—
	Fair value adjustment to contingent purchase price included in selling, general and administrative expenses:	—		—		—			—
	Balance, end of period	$	205	$	—	$	205		$	—
	The Company measures the fair value of the contingent purchase price using a Monte Carlo simulation. Using this approach, the present value of each of the milestone payments is calculated using the probability of milestone achievement under various different scenarios. Some of the more significant assumptions used in the valuation include (i) the probability of FDA approval for NP-1998 and (ii) the variability in net sales for NP-1998 if FDA approval is achieved. The milestone achievement probabilities range from 0% to 10%, and the milestone payment outcomes range from $0 to $5.0 million. The valuation will be performed periodically when the significant assumptions change.  Fair value adjustments will be included in selling, general and administrative expenses. There is no assurance that any of the conditions for the milestone payments will be met. Refer to Note 3 — Acquisition for more information on the milestones associated with the contingent consideration liability.
	The contingent purchase price has been classified as a Level 3 liability as its valuation requires substantial judgment and estimation of factors that are not currently observable in the market. If different assumptions were used for the various inputs to the valuation approach including, but not limited to, assumptions involving the probability of FDA approval for NP-1998 and the likelihood of trigger events, the estimated fair value could be significantly higher or lower than the fair value we determined. The Company may be required to record losses in future periods.

Investments

Investments	9 Months Ended
	Sep. 30, 2013
Investments	'
Investments	'
	(8) Investments
	The Company has determined that all of its investments are classified as available-for-sale. Available-for-sale securities are carried at fair value with interest on these securities included in interest income and are recorded based primarily on quoted market prices. Available-for-sale securities consisted of the following:
	(In thousands)	Amortized		Gross		Gross			Estimated
		Cost		unrealized		unrealized			fair
				gains		losses			value
	September 30, 2013
	US Treasury bonds	$	302,948	$	164	$	—		$	303,112
	December 31, 2012
	US Treasury bonds	291,209		104		(1		)	291,312
	The contractual maturities of short-term available-for-sale debt securities at September 30, 2013 and December 31, 2012 are greater than 3 months but less than 1 year. The contractual and intended maturities of long-term available-for-sale debt securities at September 30, 2013 and December 31, 2012 are greater than 1 year and up to 15 months. The Company has determined that there were no other-than-temporary declines in the fair values of its investments as of September 30, 2013.
	Short-term investments with maturity of three months or less from date of purchase have been classified as cash equivalents, and amounted to $38.4 million and $27.9 million as of September 30, 2013 and December 31, 2012, respectively.
	The Company holds available-for-sale investment securities which are reported at fair value on the Company’s balance sheet. Unrealized holding gains and losses are reported within accumulated other comprehensive income (AOCI) in the statements of comprehensive (loss) income.  The changes in AOCI associated with the unrealized holding gain on available-for-sale investments during the nine months ended September 30, 2013, were as follows (in thousands):
	(In thousands)	Net Unrealized		Total
		Gains (Losses) on
		Marketable
		Securities
	Balance at December 31, 2012	$	62	$	62
	Other comprehensive income before reclassifications:	36		36
	Amounts reclassified from accumulated other comprehensive income	—		—
	Net current period other comprehensive income	36		36
	Balance at September 30, 2013	$	98	$	98

Collaborations_Alliances_and_O

Collaborations, Alliances, and Other Agreements	9 Months Ended
	Sep. 30, 2013
Collaborations, Alliances, and Other Agreements	'
Collaborations, Alliances, and Other Agreements	'
	(9) Collaborations, Alliances, and Other Agreements
	Biogen
	On June 30, 2009, the Company entered into an exclusive collaboration and license agreement with Biogen Idec International GmbH (Biogen Idec) to develop and commercialize Ampyra (known as Fampyra outside the U.S.) in markets outside the United States (the “Collaboration Agreement”). Under the Collaboration Agreement, Biogen Idec was granted the exclusive right to commercialize Ampyra and other products containing aminopyridines developed under that agreement in all countries outside of the United States, which grant includes a sublicense of the Company’s rights under an existing license agreement between the Company and Alkermes plc (Alkermes), formerly Elan Corporation, plc (Elan). Biogen Idec has responsibility for regulatory activities and future clinical development of Fampyra in ex-U.S. markets worldwide. The Company also entered into a related supply agreement with Biogen Idec (the “Supply Agreement”), pursuant to which the Company will supply Biogen Idec with its requirements for the licensed products through the Company’s existing supply agreement with Alkermes.
	Under the Collaboration Agreement, the Company was entitled to an upfront payment of $110.0 million as of June 30, 2009, which was received in July 2009, and a $25.0 million milestone payment upon approval of the product in the European Union, which was received in August 2011. The Company is also entitled to receive additional payments of up to $10.0 million based on the successful achievement of future regulatory milestones and up to $365.0 million based on the successful achievement of future sales milestones. Due to the uncertainty surrounding the achievement of the future regulatory and sales milestones, these payments will not be recognized as revenue unless and until they are earned. The Company is not able to reasonably predict if and when the milestones will be achieved. Under the Collaboration Agreement, Biogen Idec will be required to make double-digit tiered royalty payments to the Company on ex-U.S. sales. In addition, the consideration that Biogen Idec will pay for licensed products under the Supply Agreement will reflect the price owed to the Company’s suppliers under its supply arrangements with Alkermes or other suppliers for ex-U.S. sales. The Company and Biogen Idec may also carry out future joint development activities regarding licensed product under a cost-sharing arrangement. Under the terms of the Collaboration Agreement, the Company, in part through its participation in joint committees with Biogen Idec, will participate in overseeing the development and commercialization of Ampyra and other licensed products in markets outside the United States pursuant to that agreement. Acorda will continue to develop and commercialize Ampyra independently in the United States.
	As of September 30, 2009, the Company recorded a license receivable and deferred revenue of $110.0 million for the upfront payment due to the Company from Biogen Idec under the Collaboration Agreement. Also, as a result of such payment to Acorda, a payment of $7.7 million became payable by Acorda to Alkermes and was recorded as a cost of license payable and deferred expense. The payment of $110.0 million was received from Biogen Idec on July 1, 2009 and the payment of $7.7 million was made to Alkermes on July 7, 2009.
	The Company considered the following deliverables with respect to the revenue recognition of the $110.0 million upfront payment:  (1) the license to use the Company’s technology, (2) the Collaboration Agreement to develop and commercialize licensed product in all countries outside the U.S., and (3) the Supply Agreement. Due to the inherent uncertainty in obtaining regulatory approval, the applicability of the Supply Agreement is outside the control of the Company and Biogen Idec. Accordingly, the Company has determined the Supply Agreement is a contingent deliverable at the onset of the agreement.  As a result, the Company has determined the Supply Agreement does not meet the definition of a deliverable that needs to be accounted for at the inception of the arrangement. The Company has also determined that there is no significant and incremental discount related to the supply agreement since Biogen Idec will pay the same amount for inventory that the Company would pay and the Company effectively acts as a middle man in the arrangement for which it adds no significant value due to various factors such as the Company does not have any manufacturing capabilities or other knowhow with respect to the manufacturing process.
	The Company has determined that the identified non-contingent deliverables (deliverables 1 and 2 immediately preceding) would have no value on a standalone basis if they were sold separately by a vendor and the customer could not resell the delivered items on a standalone basis, nor does the Company have objective and reliable evidence of fair value for the deliverables. Accordingly, the non-contingent deliverables are treated as one unit of accounting.  As a result, the Company will recognize the non-refundable upfront payment from Biogen Idec as revenue and the associated payment to Alkermes as expense ratably over the estimated term of regulatory exclusivity for the licensed products under the Collaboration Agreement as the Company had determined this was the most probable expected benefit period. The Company recognized $2.3 million and $6.8 million in license revenue, a portion of the $110.0 million received from Biogen Idec, and $159,000 and $476,000 in cost of license revenue, a portion of the $7.7 million paid to Alkermes, during the three and nine-month periods ended September 30, 2013, respectively.
	On January 21, 2011 Biogen Idec announced that the European Medicines Agency’s (EMA) Committee for Medicinal Products for Human Use (CHMP) decided against approval of Fampyra to improve walking ability in adult patients with multiple sclerosis.  Biogen Idec, working closely with the Company, filed a formal appeal of the decision.  In May 2011, the CHMP recommended conditional marketing authorization, and in July 2011 Biogen Idec received conditional approval from the European Commission for, Fampyra (prolonged-release fampridine tablets) for the improvement of walking in adult patients with MS with walking disability (Expanded Disability Status Scale of 4-7). The Company currently estimates the recognition period to be approximately 12 years from the date of the Collaboration Agreement. As part of its ex-U.S. license agreement, Biogen Idec owes Acorda royalties based on ex-U.S. net sales, and milestones based on ex-U.S. regulatory approval, new indications, and ex-U.S. net sales.  These milestones included a $25.0 million payment for approval of the product in the European Union which was recorded and paid in the three month period ended September 30, 2011. Based on Acorda’s worldwide license and supply agreement with Alkermes, Alkermes received 7% of this milestone payment from Acorda during the same period.  For revenue recognition purposes, the Company determined this milestone to be substantive in accordance with applicable accounting guidance related to milestone revenue.  Substantive uncertainty existed at the inception of the arrangement as to whether the milestone would be achieved because of the numerous variables, such as the high rate of failure inherent in the research and development of new products and the uncertainty involved with obtaining regulatory approval. Biogen Idec leveraged Acorda’s U.S. Ampyra study results that contributed to the regulatory approval process. Therefore, the milestone was achieved based in part on Acorda’s past performance.  The milestone was also reasonable relative to all deliverable and payment terms of the collaboration arrangement. Therefore, the payment was recognized in its entirety as revenue and the cost of the milestone revenue was recognized in its entirety as an expense during the three-month period ended September 30, 2011.
	Actavis/Watson
	The Company has an agreement with Watson Pharma, Inc., a subsidiary of Actavis, Inc. (formerly Watson Pharmaceuticals, Inc.), to market tizanidine hydrochloride capsules, an authorized generic version of Zanaflex Capsules which was launched in February 2012.  In accordance with the Watson agreement, the Company receives a royalty based on Watson’s gross margin, as defined by the agreement, of the authorized generic product. During the three-month periods ended September 30, 2013 and 2012, the Company recognized royalty revenue of $869,000 and $1.5 million, respectively, related to the gross margin of the Zanaflex Capsule authorized generic.  During the three-month periods ended September 30, 2013 and 2012, the Company also recognized revenue and a corresponding cost of sales of $1.0 million and $550,000, respectively, related to the purchase and sale of the related Zanaflex Capsule authorized generic product to Watson, which is recorded in net product revenues and cost of sales.
	During the nine-month periods ended September 30, 2013 and 2012, the Company recognized royalty revenue of $6.0 million and $4.7 million, respectively, related to the gross margin of the Zanaflex Capsule authorized generic.  During the nine-month periods ended September 30, 2013 and 2012, the Company also recognized revenue and a corresponding cost of sales of $2.7 and $2.0 million, respectively, related to the purchase and sale of the related Zanaflex Capsule authorized generic product to Watson, which is recorded in net product revenues and cost of sales.
	Neuronex
	In December 2012, the Company acquired Neuronex, Inc., a privately-held development stage pharmaceutical company (Neuronex).  Neuronex is developing Diazepam Nasal Spray under Section 505(b)(2) of the Food, Drug and Cosmetic Act as an acute treatment for selected, refractory patients with epilepsy, on stable regimens of antiepileptic drugs, or AEDs, who require intermittent use of diazepam to control bouts of increased seizure activity also known as cluster or acute repetitive seizures, or ARS.
	Under the terms of the agreement, the Company made an upfront payment of $2.0 million in February 2012.  The Company also paid $1.5 million during the twelve month period ended December 31, 2012 pursuant to a commitment under the agreement to fund research to prepare for the Diazepam Nasal Spray pre-NDA meeting with the Food and Drug Administration (FDA).  In December 2012, the Company completed the acquisition by paying $6.8 million to former Neuronex shareholders less a $300,000 holdback provision to be settled in December 2013.
	The former equity holders of Neuronex are entitled to receive from Acorda up to an additional $18.0 million in contingent earnout payments upon the achievement of specified regulatory and manufacturing-related milestones with respect to the Diazepam Nasal Spray product, and up to $105.0 million upon the achievement of specified sales milestones with respect to the Diazepam Nasal Spray product.  The former equity holders of Neuronex will also be entitled to receive tiered royalty-like earnout payments, ranging from the upper single digits to lower double digits, on worldwide net sales of Diazepam Nasal Spray products.  These payments are payable on a country-by-country basis until the earlier to occur of ten years after the first commercial sale of a product in such country and the entry of generic competition in such country as defined in the Agreement.
	The patent and other intellectual property and other rights relating to the Diazepam Nasal Spray product are licensed from SK Biopharmaceuticals Co., Ltd. (SK).  Pursuant to the SK license, which granted worldwide rights to Neuronex, except certain specified Asian countries, the Company’s subsidiary Neuronex is obligated to pay SK up to $8.0 million upon the achievement of specified development milestones with respect to the Diazepam Nasal Spray product and up to $3.0 million upon the achievement of specified sales milestones with respect to the Diazepam Nasal Spray product.  A $1.0 million milestone was triggered during the three-month period ending September 30, 2013 upon the acceptance of an FDA new drug application (NDA).  Also, Neuronex is obligated to pay SK a tiered, mid-single digit royalty on net sales of Diazepam Nasal Spray products.
	The Company evaluated the transaction based upon the guidance of ASC 805, Business Combinations, and concluded that it only acquired inputs and did not acquire any processes.  At the time of acquisition the Company had to develop its own processes in order to produce an output. Therefore the Company accounted for the transaction as an asset acquisition and accordingly the $2.0 million upfront payment, $1.5 million in research funding and $6.8 million of closing consideration net of tangible net assets acquired of $3.7 million which were primarily the taxable amount of net operating loss carryforwards, were expensed as research and development expense during the twelve-month period ended December 31, 2012.

Commitments_and_Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2013
Commitments and Contingencies	'
Commitments and Contingencies	'
	(10) Commitments and Contingencies
	A summary of the Company’s commitments and contingencies was included in the Company’s Annual Report on Form 10-K for the twelve-month period ended December 31, 2012. The Company’s long-term contractual obligations include commitments and estimated purchase obligations entered into in the normal course of business.
	The Company accrues for amounts related to legal matters if it is probable that a liability has been incurred and the amount is reasonably estimable. While losses, if any, are possible, the Company is not able to estimate any ranges of losses as of September 30, 2013. Litigation expenses are expensed as incurred.

Summary_of_Significant_Account1

Summary of Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2013
Summary of Significant Accounting Policies	'
Principles of Consolidation	'
	Principles of Consolidation
	The accompanying consolidated financial statements are prepared in accordance with accounting principles generally accepted in the United States of America and include the results of operations of the Company and its majority owned subsidiaries. All intercompany accounts and transactions have been eliminated in consolidation.
Use of Estimates	'
	Use of Estimates
	The preparation of the consolidated financial statements requires management of the Company to make a number of estimates and assumptions relating to the reported amount of assets and liabilities and the disclosure of contingent assets and liabilities at the date of the consolidated financial statements and the reported amounts of revenues and expenses during the period. Significant items subject to such estimates and assumptions include share-based compensation accounting, which are largely dependent on the fair value of the Company’s equity securities. In addition, the Company recognizes Zanaflex revenue based on estimated prescriptions filled. The Company adjusts its Zanaflex inventory value based on an estimate of inventory that may be returned. Actual results could differ from those estimates.
Investments	'
	Investments
	Both short-term and long-term investments consist of US Treasury bonds. The Company classifies marketable securities available to fund current operations as short-term investments in current assets on its consolidated balance sheets. Marketable securities are classified as long-term investments in long-term assets on the consolidated balance sheets if the Company has the ability and intent to hold them and such holding period is longer than one year. The Company classifies its short-term and long-term investments as available-for-sale. Available-for-sale securities are recorded at fair value of the investments based on quoted market prices.
	Unrealized holding gains and losses on available-for-sale securities, which are determined to be temporary, are excluded from earnings and are reported as a separate component of accumulated other comprehensive income (loss).
	Premiums and discounts on investments are amortized over the life of the related available-for-sale security as an adjustment to yield using the effective-interest method. Dividend and interest income are recognized when earned. Amortized premiums and discounts, dividend and interest income and realized gains and losses are included in interest income.
Accumulated Other Comprehensive Income	'
	Accumulated Other Comprehensive Income
	The Company’s accumulated other comprehensive income is comprised of gains and losses on available for sale securities and is recorded and presented net of income tax.
Revenue Recognition	'
	Revenue Recognition
	Ampyra
	Ampyra is available only through a network of specialty pharmacy providers that provide the medication to patients by mail; Kaiser Permanente, which distributes Ampyra to patients through a closed network of on-site pharmacies; and ASD Specialty Healthcare, Inc. (an AmerisourceBergen affiliate), which is the exclusive specialty pharmacy distributor for Ampyra to the U.S. Bureau of Prisons and the U.S. Department of Veterans Affairs (VA). Ampyra is not available in retail pharmacies. The Company does not recognize revenue from product sales until there is persuasive evidence of an arrangement, delivery has occurred, the price is fixed and determinable, the buyer is obligated to pay the Company, the obligation to pay is not contingent on resale of the product, the buyer has economic substance apart from the Company, the Company has no obligation to bring about the sale of the product, and the amount of returns can be reasonably estimated and collectability is reasonably assured. The Company recognizes product sales of Ampyra following shipment of product to a network of specialty pharmacy providers, Kaiser Permanente, and the specialty distributor to the VA. The specialty pharmacy providers, Kaiser Permanente, and the specialty distributor to the VA are contractually obligated to hold no more than an agreed number of days of inventory, ranging from 10 to 30 days.
	The Company’s net revenues represent total revenues less allowances for customer credits, including estimated rebates, discounts and returns. These allowances are recorded for cash consideration given by a vendor to a customer that is presumed to be a reduction of the selling prices of the vendor’s products or services and, therefore, are characterized as a reduction of revenue. At the time product is shipped to specialty pharmacies, Kaiser Permanente and the specialty distributor to the VA, an adjustment is recorded for estimated rebates, discounts and returns. These allowances are established by management as its best estimate based on available information and will be adjusted to reflect known changes in the factors that impact such allowances. Allowances for rebates, discounts and returns are established based on the contractual terms with customers, historical trends, communications with customers and the levels of inventory remaining in the distribution channel, as well as expectations about the market for the product and anticipated introduction of competitive products.  Product shipping and handling costs are included in cost of sales.  Effective December 1, 2012, the Company no longer accepts returns of Ampyra with the exception of product damages that occur during shipping.
	Zanaflex
	The Company applies the revenue recognition guidance in Accounting Standards Codification (ASC) 605-15-25, which among other criteria requires that future returns can be reasonably estimated in order to recognize revenue. The amount of future tablet returns is uncertain due to generic competition and customer conversion to Zanaflex Capsules. The Company has accumulated some sales history with Zanaflex Capsules; however, due to existing and potential generic competition and customer conversion from Zanaflex tablets to Zanaflex Capsules, we do not believe we can reasonably determine a return rate at this time. As a result, the Company accounts for these product shipments using a deferred revenue recognition model. Under the deferred revenue model, the Company does not recognize revenue upon product shipment. For these product shipments, the Company invoices the wholesaler, records deferred revenue at gross invoice sales price, and classifies the cost basis of the product held by the wholesaler as a component of inventory. The Company recognizes revenue when prescribed to the end-user, on a first-in first-out (FIFO) basis. The Company’s revenue to be recognized is based on (1) the estimated prescription demand, based on pharmacy sales for its products; and (2) the Company’s analysis of third-party information, including third-party market research data. The Company’s estimates are subject to the inherent limitations of estimates that rely on third-party data, as certain third-party information is itself in the form of estimates, and reflect other limitations. The Company’s sales and revenue recognition reflects the Company’s estimates of actual product prescribed to the end-user. The Company expects to be able to apply a more traditional revenue recognition policy such that revenue is recognized following shipment to the customer when it believes it has sufficient data to develop reasonable estimates of expected returns based upon historical returns and greater certainty regarding generic competition.
	The Company’s net revenues represent total revenues less allowances for customer credits, including estimated discounts, rebates, and chargebacks. These allowances are recorded for cash consideration given by a vendor to a customer that is presumed to be a reduction of the selling prices of the vendor’s products or services and, therefore, should be characterized as a reduction of revenue when recognized in the vendor’s statement of operations. Adjustments are recorded for estimated chargebacks, rebates, and discounts. These allowances are established by management as its best estimate based on available information and are adjusted to reflect known changes in the factors that impact such allowances. Allowances for chargebacks, rebates and discounts are established based on the contractual terms with customers, analysis of historical levels of discounts, chargebacks and rebates, communications with customers and the levels of inventory remaining in the distribution channel, as well as expectations about the market for each product and anticipated introduction of competitive products. In addition, the Company records a charge to cost of goods sold for the cost basis of the estimated product returns the Company believes may ultimately be realized at the time of product shipment to wholesalers. The Company has recognized this charge at the date of shipment since it is probable that it will receive a level of returned products; upon the return of such product it will be unable to resell the product considering its expiration dating; and it can reasonably estimate a range of returns. This charge represents the cost basis for the low end of the range of the Company’s estimated returns. Product shipping and handling costs are included in cost of sales.
	Qutenza
	Qutenza is sold through a specialty distributor, who sells Qutenza to physician offices, hospitals, clinics, and specialty pharmacies. The Company does not recognize revenue from product sales until there is persuasive evidence of an arrangement, delivery has occurred, the price is fixed and determinable, the buyer is obligated to pay the Company, the obligation to pay is not contingent on resale of the product, the buyer has economic substance apart from the Company, the Company has no obligation to bring about the sale of the product, and the amount of returns can be reasonably estimated and collectability is reasonably assured. This means that, for Qutenza, the Company recognizes product sales following shipment of product to its specialty distributor.
	The Company’s net revenues represent total revenues less allowances for customer credits, including estimated rebates and returns. These allowances are recorded for cash consideration given by a vendor to a customer that is presumed to be a reduction of the selling prices of the vendor’s products or services and, therefore, are characterized as a reduction of revenue. At the time product is shipped, an adjustment is recorded for estimated rebates and returns. These allowances are established by management as its best estimate based on available information and will be adjusted to reflect known changes in the factors that impact such allowances. Allowances for rebates and returns are established based on the contractual terms with customers, historical trends, as well as expectations about the market for the product and anticipated introduction of competitive products.  Product shipping and handling costs are included in cost of sales.
	Milestones and royalties
	In order to determine the revenue recognition for contingent milestones, the Company evaluates the contingent milestones using the criteria as provided by the Financial Accounting Standards Boards (FASB) guidance on the milestone method of revenue recognition. At the inception of a collaboration agreement the Company evaluates if payments are substantive.  The criteria requires that (i) the Company determines if the milestone is commensurate with either its performance to achieve the milestone or the enhancement of value resulting from the Company’s activities to achieve the milestone, (ii) the milestone be related to past performance, and (iii) the milestone be reasonable relative to all deliverable and payment terms of the collaboration arrangement.  If these criteria are met then the contingent milestones can be considered substantive milestones and will be recognized as revenue in the period that the milestone is achieved. Royalties are recognized as earned in accordance with the terms of various research and collaboration agreements.
In-Process Research and Development	'
	In-Process Research and Development
	The cost of in-process research and development (IPR&D) acquired directly in a transaction other than a business combination is capitalized if the projects will be further developed or have an alternative future use; otherwise they are expensed. The fair values of IPR&D projects acquired in business combinations are capitalized. Several methods may be used to determine the estimated fair value of the IPR&D acquired in a business combination. The Company utilizes the “income method,” and uses estimated future net cash flows that are derived from projected sales revenues and estimated costs. These projections are based on factors such as relevant market size, patent protection, historical pricing and expected industry trends. The estimated future net cash flows are then discounted to the present value using an appropriate discount rate. These assets are treated as indefinite-lived intangible assets until completion or abandonment of the projects, at which time the assets are amortized over the remaining useful life or written off, as appropriate. IPR&D intangible assets which are determined to have had a drop in their fair value are adjusted downward and an expense recognized on the statement of operations. These are tested at least annually or sooner when a triggering event occurs that could indicate a potential impairment.
Collaborations	'
	Collaborations
	The Company recognizes collaboration revenues and expenses by analyzing each element of the agreement to determine if it shall be accounted for as a separate element or single unit of accounting. If an element shall be treated separately for revenue recognition purposes, the revenue recognition principles most appropriate for that element are applied to determine when revenue shall be recognized. If an element shall not be treated separately for revenue recognition purposes, the revenue recognition principles most appropriate for the bundled group of elements are applied to determine when revenue shall be recognized. Payments received in excess of revenues recognized are recorded as deferred revenue until such time as the revenue recognition criteria have been met.
Concentration of Credit Risk	'
	Concentration of Credit Risk
	The Company’s principal direct customers as of September 30, 2013 were a network of specialty pharmacies, Kaiser Permanente, and the specialty distributor to the VA for Ampyra, wholesale pharmaceutical distributors for Zanaflex Capsules and Zanaflex tablets, and a specialty distributor for Qutenza. The Company periodically assesses the financial strength of these customers and establishes allowances for anticipated losses, if necessary. Four customers individually accounted for more than 10% of the Company’s revenue in 2013 and 2012, and three customers in 2011. Four customers individually accounted for more than 10% of the Company’s accounts receivable as of September 30, 2013 and December 31, 2012. The Company’s net product revenues are generated in the United States.
Segment and Geographic Information	'
	Segment and Geographic Information
	The Company is managed and operated as one business which is focused on the identification, development and commercialization of novel therapies that improve neurological function in people with MS, SCI and other disorders of the central nervous system. The entire business is managed by a single management team that reports to the chief executive officer. The Company does not operate separate lines of business with respect to any of its products or product candidates and the Company does not prepare discrete financial information with respect to separate products or product candidates or by location.  Accordingly, the Company views its business as one reportable operating segment. Net product revenues reported to date are derived from the sales of Ampyra, Zanaflex and Qutenza in the United States.
Subsequent Events	'
	Subsequent Events
	Subsequent events are defined as those events or transactions that occur after the balance sheet date, but before the financial statements are filed with the Securities and Exchange Commission. The Company completed an evaluation of the impact of any subsequent events through the date these financial statements were issued, and determined there were no subsequent events requiring disclosure in or requiring adjustment to these financial statements.
Recent Accounting Pronouncements	'
	Recent Accounting Pronouncements
	In February 2013, the FASB amended its guidance to require an entity to present the effect of certain significant reclassifications out of accumulated other comprehensive income on the respective line items in net income. The new accounting guidance does not change the items that must be reported in other comprehensive income or when an item of other comprehensive income must be reclassified to net income. The guidance is effective prospectively for fiscal years beginning after December 15, 2012. The Company adopted these new provisions for the quarter beginning January 1, 2013. As the guidance requires additional presentation only, there was no impact to the Company’s consolidated results of operations or financial position.
	In July 2013, the FASB issued ASU 2013-11, Presentation of an Unrecognized Tax Benefit When a Net Operating Loss Carryforward, a Similar Tax Loss, or a Tax Credit Carryforward Exists, (ASU 2013-11), an amendment to ASC 740, Income Taxes. ASU 2013-11 clarifies that an unrecognized tax benefit, or a portion of an unrecognized tax benefit, should be presented in the financial statements as a reduction to a deferred tax asset for a net operating loss carryforward, a similar tax loss, or a tax credit carryforward if such settlement is required or expected in the event the uncertain tax benefit is disallowed. In situations where a net operating loss carryforward, a similar tax loss, or a tax credit carryforward is not available at the reporting date under the tax law of the applicable jurisdiction or the tax law of the jurisdiction does not require, and the entity does not intend to use, the deferred tax asset for such purpose, the unrecognized tax benefit should be presented in the financial statements as a liability and should not be netted with the deferred tax asset. The amendments in ASU 2013-11 are effective for fiscal years, and interim periods within those years, beginning after December 15, 2013. Early adoption is permitted. The amendments should be applied prospectively to all unrecognized tax benefits that exist at the effective date. Retrospective application is permitted. The Company is currently evaluating the impact that adoption will have on the determination or reporting of its financial results.

Acquisition_Tables

Acquisition (Tables)	9 Months Ended
	Sep. 30, 2013
Acquisition	'
Summary of preliminary estimated purchase price	'
	(in thousands)
	Cash paid to NeurogesX shareholders and its creditors	$	7,499
	Fair value of contingent liabilities	205
	Total preliminary estimated purchase price	$	7,704
Schedule of preliminary allocation of purchase price to assets acquired	'
	(in thousands)
	Inventory	$	90
	Equipment	173
	Identifiable intangible assets:
	Developed technology - Qutenza	450
	In-process research and development – NP-1998	6,991
	Fair value of acquired assets	7,704
	Aggregate purchase price	7,704
	Goodwill	$	—
Summary of supplemental pro forma financial information	'
		Three-month period ended				Three-month period ended
		September 30, 2013				September 30, 2012
	(In thousands)	Reported		Pro Forma		Reported		Pro Forma
	Net revenues	$	84,919	$	84,919	$	77,437	$	80,285
	Net income	7,477		7,477		9,594		3,595
		Nine-month period ended				Nine-month period ended
		September 30, 2013				September 30, 2012
	(In thousands)	Reported		Pro Forma		Reported		Pro Forma
	Net revenues	$	243,838	$	249,122	$	224,342	$	232,887
	Net income	10,250		6,751		21,985		3,988

Sharebased_Compensation_Tables

Share-based Compensation (Tables)	9 Months Ended
	Sep. 30, 2013
Share-based Compensation	'
Summary of share-based compensation expense	'
		For the three-month						For the nine-month
		period ended September 30,						period ended September 30,
	(In millions)	2013			2012			2013			2012
	Research and development	$	1.5		$	1.4		$	4.2		$	3.7
	Selling, general and administrative	5			4.2			13.8			11.6
	Total	$	6.5		$	5.6		$	18		$	15.3
Summary of stock option activity	'
		Number of Shares		Weighted Average			Weighted Average		Intrinsic Value
		(In thousands)		Exercise Price			Remaining		(In thousands)
							Contractual
							Term
	Balance at January 1, 2013	5,667		$	22.3
	Granted	1,600		31.05
	Cancelled	(165	)	27.48
	Exercised	(797	)	15.29
	Balance at September 30, 2013	6,305		$	25.27		7		$	56,639
	Vested and expected to vest at September 30, 2013	6,237		$	25.22		7		$	56,316
	Vested and exercisable at September 30, 2013	3,675		$	22.97		5.7		$	41,346
Summary of restricted stock activity	'
	(In thousands)	Number of Shares
	Restricted Stock
	Nonvested at January 1, 2013	458
	Granted	211
	Vested	(22	)
	Forfeited	(30	)
	Nonvested at September 30, 2013	617

Earnings_Per_Share_Tables

Earnings Per Share (Tables)	9 Months Ended
	Sep. 30, 2013
Earnings Per Share	'
Schedule of computation of basic and diluted earnings per share	'
	(In thousands, except per share data)	Three-month			Three-month		Nine-month		Nine-month
		period ended			period ended		period ended		period ended
		September 30, 2013			September 30, 2012		September 30, 2013		September 30, 2012
	Basic and diluted
	Net income	$	7,477		$	9,594	$	10,250	$	21,985
	Weighted average common shares outstanding used in computing net income per share—basic	40,315			39,463		40,037		39,412
	Plus: net effect of dilutive stock options and restricted common shares	1,681			696		1,504		810
	Weighted average common shares outstanding used in computing net income per share—diluted	41,996			40,159		41,541		40,222
	Net income per share—basic	$	0.19		$	0.24	$	0.26	$	0.56
	Net income per share—diluted	$	0.18		$	0.24	$	0.25	$	0.55
Schedule of antidilutive securities excluded from computation of earnings per share	'
	(In thousands)	Three-month		Three-month		Nine-month	Nine-month
		period ended		period ended		period ended	period ended
		September 30,		September 30,		September 30,	September 30,
		2013		2012		2013	2012
	Denominator
	Stock options and restricted common shares	1,558		3,910		2,786	3,831
	Convertible note	39		48		39	48

Fair_Value_Measurements_Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2013
Fair Value Measurements	'
Schedule of assets and liabilities measured at fair value on a recurring basis	'
	(In thousands)	Level 1		Level 2		Level 3
	September 30, 2013
	Assets Carried at Fair Value:
	Cash equivalents	$	38,381	$	—	$	—
	Short-term investments	—		246,043		—
	Long-term investments	—		57,069		—
	Liabilities Carried at Fair Value:
	Put/call liability	—		—		—
	Contingent purchase price	—		—		205
	December 31, 2012
	Assets Carried at Fair Value:
	Cash equivalents	$	27,932	$	—	$	—
	Short-term investments	—		191,949		—
	Long-term investments	—		99,363		—
	Liabilities Carried at Fair Value:
	Put/call liability	—		—		329
	Contingent purchase price	—		—		—
Schedule of assets and liabilities measured at fair value on a recurring basis utilizing Level 3 inputs	'
	(In thousands)	Three-month		Three-month		Nine-month			Nine-month
		period ended		period ended		period ended			period ended
		September 30,		September 30,		September 30,			September 30,
		2013		2012		2013			2012
	Put/call liability:
	Balance, beginning of period	$	—	$	511	$	329		$	1,030
	Total realized and unrealized gains included in selling, general and administrative expenses:	—		43		(329		)	(476		)
	Balance, end of period	$	—	$	554	$	—		$	554
Schedule of contingent purchase price	'
	(In thousands)	Three-month		Three-month		Nine-month			Nine-month
		period ended		period ended		period ended			period ended
		September 30,		September 30,		September 30,			September 30,
		2013		2012		2013			2012
	Contingent purchase price:
	Balance, beginning of period	$	—	$	—	$	—		$	—
	Fair value of contingent purchase price as of July 8, 2013	205		—		205			—
	Fair value adjustment to contingent purchase price included in selling, general and administrative expenses:	—		—		—			—
	Balance, end of period	$	205	$	—	$	205		$	—

Investments_Tables

Investments (Tables)	9 Months Ended
	Sep. 30, 2013
Investments	'
Schedule of available-for-sale securities	'
	(In thousands)	Amortized		Gross		Gross			Estimated
		Cost		unrealized		unrealized			fair
				gains		losses			value
	September 30, 2013
	US Treasury bonds	$	302,948	$	164	$	—		$	303,112
	December 31, 2012
	US Treasury bonds	291,209		104		(1		)	291,312
Schedule of changes in accumulated other comprehensive income	'
	The changes in AOCI associated with the unrealized holding gain on available-for-sale investments during the nine months ended September 30, 2013, were as follows (in thousands):
	(In thousands)	Net Unrealized		Total
		Gains (Losses) on
		Marketable
		Securities
	Balance at December 31, 2012	$	62	$	62
	Other comprehensive income before reclassifications:	36		36
	Amounts reclassified from accumulated other comprehensive income	—		—
	Net current period other comprehensive income	36		36
	Balance at September 30, 2013	$	98	$	98

Summary_of_Significant_Account2

Summary of Significant Accounting Policies (Details) (Ampyra)	9 Months Ended
	Sep. 30, 2013
Minimum	'
Revenue Recognition	'
Contractually obligated inventory holdings period	'10 days
Maximum	'
Revenue Recognition	'
Contractually obligated inventory holdings period	'30 days

Summary_of_Significant_Account3

Summary of Significant Accounting Policies (Details 2)	9 Months Ended	12 Months Ended
	Sep. 30, 2013	Dec. 31, 2012	Dec. 31, 2011
	customer	customer	customer
Segment and Geographic Information	'	'	'
Number of reportable operating segments	1	'	'
Revenue	'	'	'
Concentration of Risk - greater than 10% of total	'	'	'
Number of customers	4	4	3
Accounts receivable	'	'	'
Concentration of Risk - greater than 10% of total	'	'	'
Number of customers	4	4	'

Acquisition_Details

Acquisition (Details) (USD $)	0 Months Ended	3 Months Ended		9 Months Ended
	Jul. 08, 2013	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
	item
Estimated purchase price :	'	'	'	'	'
Cash paid to NeurogesX shareholders and its creditors	'	'	'	$7,499,000	'
Pro Forma Financial Information (Unaudited)	'	'	'	'	'
Reported net revenues	'	84,919,000	77,437,000	243,838,000	224,342,000
Reported net income	'	7,477,000	9,594,000	10,250,000	21,985,000
NeurogesX	'	'	'	'	'
Acquisition	'	'	'	'	'
Number of neuropathic pain management assets acquired	2	'	'	'	'
Acquisition-related costs	'	'	'	1,000,000	'
Estimated purchase price :	'	'	'	'	'
Cash paid to NeurogesX shareholders and its creditors	7,499,000	'	'	'	'
Fair value of contingent liabilities	205,000	'	'	'	'
Total preliminary estimated purchase price	7,704,000	'	'	7,704,000	'
Allocation of purchase price to assets acquired	'	'	'	'	'
Inventory	90,000	'	'	'	'
Equipment	173,000	'	'	'	'
Fair value of acquired assets	7,704,000	'	'	'	'
Aggregate purchase price	7,704,000	'	'	7,704,000	'
Pro Forma Financial Information (Unaudited)	'	'	'	'	'
Reported net revenues	'	84,919,000	77,437,000	243,838,000	224,342,000
Reported net income	'	7,477,000	9,594,000	10,250,000	21,985,000
Pro Forma net revenues	'	84,919,000	80,285,000	249,122,000	232,887,000
Pro Forma net income	'	7,477,000	3,595,000	6,751,000	3,988,000
NeurogesX | Maximum	'	'	'	'	'
Acquisition	'	'	'	'	'
Contingent milestone payments	5,000,000	'	'	'	'
NeurogesX | Non-recurring pro forma adjustment related to transaction costs	'	'	'	'	'
Acquisition	'	'	'	'	'
Acquisition-related costs	'	'	'	1,700,000	'
Qutenza and NP-1998 | Astellas Pharma Europe	'	'	'	'	'
Acquisition	'	'	'	'	'
Number of countries	'	'	'	28	'
NP-1998 | In-process research and development	'	'	'	'	'
Allocation of purchase price to assets acquired	'	'	'	'	'
Identifiable intangible assets	6,991,000	'	'	'	'
NP-1998 | Approval for sale of liquid formulation product	'	'	'	'	'
Acquisition	'	'	'	'	'
Contingent milestone payments	2,000,000	'	'	'	'
NP-1998 | Achievement of sales target	'	'	'	'	'
Acquisition	'	'	'	'	'
Contingent milestone payments	3,000,000	'	'	'	'
Target amount of sales to be achieve for contingent consideration	100,000,000	'	'	'	'
Period for achievement of sales target for contingent consideration	'12 months	'	'	'	'
Qutenza | Developed technology	'	'	'	'	'
Allocation of purchase price to assets acquired	'	'	'	'	'
Identifiable intangible assets	$450,000	'	'	'	'

Sharebased_Compensation_Detail

Share-based Compensation (Details) (USD $)	3 Months Ended		9 Months Ended
In Millions, except Per Share data, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Share-based compensation expense	'	'	'	'
Share-based compensation expense recognized	$6.50	$5.60	$18	$15.30
Weighted average fair value of options granted to employees (in dollars per share)	$18.02	$13	$15.76	$13.74
Research and development	'	'	'	'
Share-based compensation expense	'	'	'	'
Share-based compensation expense recognized	1.5	1.4	4.2	3.7
Selling, general, and administrative	'	'	'	'
Share-based compensation expense	'	'	'	'
Share-based compensation expense recognized	$5	$4.20	$13.80	$11.60

Sharebased_Compensation_Detail1

Share-based Compensation (Details 2) (USD $)	9 Months Ended
Share data in Thousands, except Per Share data, unless otherwise specified	Sep. 30, 2013
Share based compensation, other disclosures	'
Total unrecognized compensation costs related to unvested stock options and restricted stock awards that the company expects to recognize	$46,600,000
Weighted average period	'2 years 7 months 6 days
Stock Options	'
Stock Option Activity	'
Beginning balance (in shares)	5,667
Granted (in shares)	1,600
Cancelled (in shares)	-165
Exercised (in shares)	-797
Ending balance (in shares)	6,305
Vested and expected to vest at end of period (in shares)	6,237
Vested and exercisable at end of period (in shares)	3,675
Weighted Average Exercise Price	'
Balance at the beginning of the period (in dollars per share)	$22.30
Granted (in dollars per share)	$31.05
Cancelled (in dollars per share)	$27.48
Exercised (in dollars per share)	$15.29
Balance at the end of the period (in dollars per share)	$25.27
Vested and expected to vest at the end of the period (in dollars per share)	$25.22
Vested and exercisable at the end of the period (in dollars per share)	$22.97
Weighted Average Remaining Contractual Term	'
Balance at the end of the period	'7 years
Vested and expected to vest at the end of the period	'7 years
Vested and exercisable at the end of the period	'5 years 8 months 12 days
Intrinsic Value	'
Balance at the end of the period	56,639,000
Vested and expected to vest at the end of the period	56,316,000
Vested and exercisable at the end of the period	$41,346,000
Restricted Stock	'
Restricted Stock Activity	'
Nonvested at the beginning of the period (in shares)	458
Granted (in shares)	211
Vested (in shares)	-22
Forfeited (in shares)	-30
Nonvested at the end of the period (in shares)	617

Earnings_Per_Share_Details

Earnings Per Share (Details) (USD $)	3 Months Ended		9 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Basic and diluted	'	'	'	'
Net income (in dollars)	$7,477	$9,594	$10,250	$21,985
Weighted average common shares outstanding used in computing net income per share-basic	40,315	39,463	40,037	39,412
Plus: net effect of dilutive stock options and restricted common shares	1,681	696	1,504	810
Weighted average common shares outstanding used in computing net income per share-diluted	41,996	40,159	41,541	40,222
Net income per share-basic (in dollars per share)	$0.19	$0.24	$0.26	$0.56
Net income per share-diluted (in dollars per share)	$0.18	$0.24	$0.25	$0.55

Earnings_Per_Share_Details_2

Earnings Per Share (Details 2)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Stock options and restricted common shares	'	'	'	'
Antidilutive Securities	'	'	'	'
Anti-dilutive securities excluded from computation of earnings per share (in shares)	1,558	3,910	2,786	3,831
Convertible note	'	'	'	'
Antidilutive Securities	'	'	'	'
Anti-dilutive securities excluded from computation of earnings per share (in shares)	39	48	39	48

Income_Taxes_Details

Income Taxes (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Income Taxes	'	'	'	'
Income tax provision	$3,513,000	$533,000	$5,985,000	$1,185,000
Effective income tax rate (as a percent)	32.00%	5.20%	36.80%	5.10%
Tax credit	$1,200,000	'	$1,200,000	'

Fair_Value_Measurements_Detail

Fair Value Measurements (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Assets Carried at Fair Value:	'	'
Short-term investments	$246,043	$191,949
Long-term investments	57,069	99,363
Recurring basis | Level 1	'	'
Assets Carried at Fair Value:	'	'
Cash equivalents	38,381	27,932
Recurring basis | Level 2	'	'
Assets Carried at Fair Value:	'	'
Short-term investments	246,043	191,949
Long-term investments	57,069	99,363
Recurring basis | Level 3	'	'
Liabilities Carried at Fair Value:	'	'
Put/call liability	'	329
Contingent purchase price	$205	'

Fair_Value_Measurements_Detail1

Fair Value Measurements (Details 2) (USD $)	3 Months Ended	9 Months Ended			3 Months Ended	9 Months Ended
	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Jun. 30, 2013	Sep. 30, 2013	Sep. 30, 2013
	Put/call liability	Put/call liability	Put/call liability	Put/call liability	Contingent purchase price	Contingent purchase price
Assets and liabilities measured at fair value on a recurring basis utilizing Level 3 inputs	'	'	'	'	'	'
Balance, beginning of period	$511,000	$329,000	$1,030,000	$247,000	'	'
Fair value of contingent purchase price as of July 8, 2013	'	'	'	'	205,000	205,000
Total realized and unrealized gains included in selling, general and administrative expenses:	43,000	-329,000	-476,000	'	'	'
Balance, end of period	554,000	'	554,000	247,000	205,000	205,000
Milestone payment, minimum (as a percent)	'	'	'	'	0.00%	0.00%
Milestone payment, maximum (as a percent)	'	'	'	'	10.00%	10.00%
Milestone payment, minimum	'	'	'	'	0	0
Milestone payment, maximum	'	'	'	'	$5,000,000	$5,000,000

Investments_Details

Investments (Details) (USD $)	9 Months Ended	12 Months Ended
	Sep. 30, 2013	Dec. 31, 2012
Investments	'	'
Other-than-temporary declines in the fair values of investments	0	'
Short-term investments classified as cash and cash equivalents	38,400,000	27,900,000
Minimum	'	'
Investments	'	'
Short-term investments maturity term	'3 months	'3 months
Long-term investments maturity term	'1 year	'1 year
Maximum	'	'
Investments	'	'
Short-term investments maturity term	'1 year	'1 year
Long-term investments maturity term	'15 months	'15 months
US Treasury bonds	'	'
Investments	'	'
Amortized Cost	302,948,000	291,209,000
Gross unrealized gains	164,000	104,000
Gross unrealized losses	'	-1,000
Estimated fair value	303,112,000	291,312,000

Investments_Details_2

Investments (Details 2) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Changes in accumulated other comprehensive income	'	'	'	'
Balance at the beginning of the period	'	'	$62	'
Other comprehensive income before reclassifications	'	'	36	'
Other comprehensive income (loss), net of tax	44	108	36	3
Balance at the end of the period	98	'	98	'
Net Unrealized Gains (Losses) on Marketable Securities	'	'	'	'
Changes in accumulated other comprehensive income	'	'	'	'
Balance at the beginning of the period	'	'	62	'
Other comprehensive income before reclassifications	'	'	36	'
Other comprehensive income (loss), net of tax	'	'	36	'
Balance at the end of the period	$98	'	$98	'

Collaborations_Alliances_and_O1

Collaborations, Alliances, and Other Agreements (Details) (USD $)

3 Months Ended

9 Months Ended

1 Months Ended

12 Months Ended

0 Months Ended

1 Months Ended

3 Months Ended

9 Months Ended

0 Months Ended

3 Months Ended

9 Months Ended

3 Months Ended

9 Months Ended

3 Months Ended

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Sep. 30, 2012

Dec. 31, 2012

Feb. 29, 2012

Dec. 31, 2012

Sep. 30, 2013

Sep. 30, 2013

Jul. 01, 2009

Aug. 31, 2011

Sep. 30, 2009

Sep. 30, 2013

Sep. 30, 2013

Jun. 30, 2009

Jun. 30, 2009

Jul. 07, 2009

Jun. 30, 2009

Sep. 30, 2013

Sep. 30, 2011

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Sep. 30, 2013

Neuronex Acquisition

DZNS

DZNS

DZNS

DZNS

Biogen Idec

Biogen Idec

Biogen Idec

Biogen Idec

Biogen Idec

Biogen Idec

Biogen Idec

Alkermes License Agreement

Alkermes License Agreement

Alkermes License Agreement

Alkermes License Agreement

Alkermes License Agreement

Actavis/Watson

Actavis/Watson

Actavis/Watson

Actavis/Watson

SK

SK

Neuronex Acquisition

Neuronex Acquisition

Neuronex Acquisition

Neuronex Acquisition

Maximum

Maximum

DZNS

DZNS

Achievement of Manufacturing and Regulatory Milestones

Achievement of Sales Milestones

Forcast Revenue

Neuronex Acquisition

Neuronex Acquisition

Achievement of Manufacturing and Regulatory Milestones

Achievement of Sales Milestones

Collaboration agreement

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

License Revenue

'

'

'

'

'

'

'

'

'

'

$25,000,000

$110,000,000

$2,300,000

$6,800,000

'

$365,000,000

'

'

'

'

'

'

'

'

'

'

'

Additional payments based on the successful achievement of future regulatory milestones

'

'

'

'

'

'

'

'

'

'

'

'

'

'

10,000,000

'

'

'

'

'

'

'

'

'

'

'

'

Cash received

'

'

'

'

'

'

'

'

'

110,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Cost of license revenue

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

7,700,000

159,000

'

476,000

'

'

'

'

1,000,000

'

Payment for product license

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

7,700,000

'

'

'

'

'

'

'

'

'

'

Amount of significant and incremental discount related to the supply agreement

'

'

'

'

'

'

'

'

'

'

'

'

'

0

'

'

'

'

'

'

'

'

'

'

'

'

'

Identified non-contingent deliverables value on standalone basis, if sold separately

'

'

'

'

'

'

'

'

'

'

'

'

'

0

'

'

'

'

'

'

'

'

'

'

'

'

'

Current estimate of license revenue recognition period

'

'

'

'

'

'

'

'

'

'

'

'

'

'12 years

'

'

'

'

'

'

'

'

'

'

'

'

'

Portion of milestone payment from Acorda to Alkermes (as a percent)

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

7.00%

'

'

'

'

'

'

'

Royalty revenues

2,895,000

2,967,000

13,076,000

10,557,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

869,000

1,500,000

6,000,000

4,700,000

'

'

Revenue recognized

79,760,000

72,206,000

223,969,000

206,992,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

1,000,000

550,000

2,700,000

2,000,000

'

'

Cost of sales

17,213,000

14,761,000

47,631,000

40,802,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

1,000,000

550,000

2,700,000

2,000,000

'

'

Business Acquisition

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Payments recorded as research and development expense

'

'

'

'

'

2,000,000

1,500,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Payments to complete the acquisition

'

'

'

'

6,800,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Maximum contingent acquisition payment

'

'

'

'

'

'

'

18,000,000

105,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

8,000,000

3,000,000

Tangible net assets acquired, primarily the taxable amount of net operating loss carryforwards

'

'

'

'

3,700,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Holdback provision

'

'

'

'

300,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Upfront payments recorded as research and development expense

'

'

'

'

2,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Advance funding payments recorded as research and development expense

'

'

'

'

$1,500,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'