Amag Pharmaceuticals (AMAG) 10-Q 7 Nov 14 2014 Q3 Quarterly report Financial data

Document_and_Entity_Informatio

Document and Entity Information	9 Months Ended
	Sep. 30, 2014	Oct. 31, 2014
Document and Entity Information	'	'
Entity Registrant Name	'AMAG PHARMACEUTICALS INC.	'
Entity Central Index Key	'0000792977	'
Document Type	'10-Q	'
Document Period End Date	30-Sep-14	'
Amendment Flag	'false	'
Current Fiscal Year End Date	'--12-31	'
Entity Current Reporting Status	'Yes	'
Entity Filer Category	'Accelerated Filer	'
Entity Common Stock, Shares Outstanding	'	22,094,769
Document Fiscal Year Focus	'2014	'
Document Fiscal Period Focus	'Q3	'

CONDENSED_CONSOLIDATED_BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Current assets:	'	'
Cash and cash equivalents	$196,154	$26,986
Investments	190,088	186,803
Accounts receivable, net	10,873	6,842
Inventories	19,580	17,217
Receivable from collaboration	932	278
Prepaid and other current assets	9,357	3,396
Restricted cash	'	2,883
Total current assets	426,984	244,405
Property and equipment, net	1,582	1,846
Intangible assets, net	16,597	16,844
Restricted cash	400	400
Other long-term assets	5,829	1,964
Total assets	451,392	265,459
Current liabilities:	'	'
Accounts payable	1,899	2,629
Accrued expenses	27,521	22,266
Deferred revenues	9,419	8,226
Total current liabilities	38,839	33,121
Long-term liabilities:	'	'
Convertible 2.5% senior notes, net	165,778	'
Deferred Revenues	36,682	44,534
Acquisition-related contingent consideration	11,188	13,609
Other long-term liabilities	1,924	1,787
Total liabilities	254,411	93,051
Commitments and contingencies	'	'
Stockholders' equity:	'	'
Preferred stock, par value $0.01 per share, 2,000,000 shares authorized; none issued	'	'
Common stock, par value $0.01 per share, 58,750,000 shares authorized; 22,026,189 and 21,772,571 shares issued and outstanding at September 30, 2014 and December 31, 2013, respectively	220	218
Additional paid-in capital	673,767	641,941
Accumulated other comprehensive loss	-3,555	-3,491
Accumulated deficit	-473,451	-466,260
Total stockholders' equity	196,981	172,408
Total liabilities and stockholders' equity	$451,392	$265,459

CONDENSED_CONSOLIDATED_BALANCE1

CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) (USD $)	Sep. 30, 2014	Dec. 31, 2013
CONDENSED CONSOLIDATED BALANCE SHEETS	'	'
Convertible senior notes, interest rate (as a percent)	2.50%	'
Preferred stock, par value (in dollars per share)	$0.01	$0.01
Preferred stock, shares authorized	2,000,000	2,000,000
Preferred stock, shares issued	0	0
Common stock, par value (in dollars per share)	$0.01	$0.01
Common stock, shares authorized	58,750,000	58,750,000
Common stock, shares issued	22,026,189	21,772,571
Common stock, shares outstanding	22,026,189	21,772,571

CONDENSED_CONSOLIDATED_STATEME

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS (USD $)	3 Months Ended		9 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Revenues:	'	'	'	'
U.S. Feraheme product sales, net	$22,547	$19,347	$62,147	$52,381
License fee and other collaboration revenues	2,182	1,998	7,424	6,056
Other product sales and royalties	765	271	1,560	708
Total revenues	25,494	21,616	71,131	59,145
Costs and expenses:	'	'	'	'
Cost of product sales	2,968	2,547	8,548	8,634
Research and development expenses	5,358	4,530	16,396	13,983
Selling, general and administrative expenses	12,875	14,934	46,650	44,150
Total costs and expenses	21,201	22,011	71,594	66,767
Operating Income (Loss)	4,293	-395	-463	-7,622
Other income (expense):	'	'	'	'
Interest expense	-3,129	'	-7,656	'
Interest and dividend income, net	291	246	809	773
Gains on sale of assets	'	'	102	865
Gains on investments, net	3	4	17	36
Total other income (expense)	-2,835	250	-6,728	1,674
Net income (loss)	$1,458	($145)	($7,191)	($5,948)
Net income (loss) per share:	'	'	'	'
Basic (in dollars per share)	$0.07	($0.01)	($0.33)	($0.28)
Diluted (in dollars per share)	$0.06	($0.01)	($0.33)	($0.28)
Weighted average shares outstanding used to compute net income (loss) per share:	'	'	'	'
Basic (in shares)	21,984	21,691	21,912	21,613
Diluted (in shares)	23,467	21,691	21,912	21,613

CONDENSED_CONSOLIDATED_STATEME1

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS)	'	'	'	'
Net income (loss)	$1,458	($145)	($7,191)	($5,948)
Unrealized gains (losses) on securities:	'	'	'	'
Holding gains (losses) arising during period, net of tax	-305	399	-76	-310
Reclassification adjustment for (gains) losses included in net income (loss)	9	'	12	21
Net unrealized gains (losses) on securities	-296	399	-64	-289
Total comprehensive income (loss)	$1,162	$254	($7,255)	($6,237)

CONDENSED_CONSOLIDATED_STATEME2

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $)	9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013
Cash flows from operating activities:	'	'
Net income (loss)	($7,191)	($5,948)
Adjustments to reconcile net loss to net cash used in operating activities:	'	'
Depreciation and amortization	655	2,935
Amortization of premium/discount on purchased securities	1,823	2,076
Write-down of inventory to net realizable value	1,119	502
Non-cash equity-based compensation expense	6,153	5,886
Amortization of debt discount and debt issuance costs	4,531	'
Gains on sale of assets	-102	-865
Gains on investments, net	-17	-36
Change in fair value of contingent consideration	-2,535	279
Changes in operating assets and liabilities:	'	'
Accounts receivable, net	-4,031	-2,368
Inventories	-2,496	640
Receivable from collaboration	-654	13
Prepaid and other current assets	-2,211	313
Other long-term assets	1,001	'
Accounts payable and accrued expenses	87	-7,033
Deferred revenues	-6,659	-4,999
Other long-term liabilities	137	-305
Total adjustments	-3,199	-2,962
Net cash used in operating activities	-10,390	-8,910
Cash flows from investing activities:	'	'
Proceeds from sales or maturities of investments	58,592	84,454
Purchase of investments	-63,747	-88,629
Acquisition of MuGard Rights and inventory	'	-3,434
Proceeds from sale of assets	102	977
Capital expenditures	-144	-1,206
Change in restricted cash	2,883	-400
Net cash used in investing activities	-2,314	-8,238
Cash flows from financing activities:	'	'
Payment of contingent consideration	-186	-4
Proceeds from issuance of convertible debt	200,000	'
Payment of debt issuance costs	-6,711	'
Proceeds from issuance of warrants	25,620	'
Purchase of convertible bond hedges	-39,760	'
Proceeds from the exercise of stock options	2,909	1,629
Proceeds from the issuance of common stock under ESPP	'	176
Net cash provided by financing activities	181,872	1,801
Net increase (decrease) in cash and cash equivalents	169,168	-15,347
Cash and cash equivalents at beginning of the period	26,986	46,293
Cash and cash equivalents at end of the period	$196,154	$30,946

Description_of_Business1

Description of Business1	9 Months Ended
	Sep. 30, 2014
Description of Business	'
Description of Business	'
	A.Description of Business
	AMAG Pharmaceuticals, Inc., a Delaware corporation, was founded in 1981. We are a specialty pharmaceutical company that markets Feraheme®  (ferumoxytol) Injection for Intravenous (“IV”) use to treat iron deficiency anemia (“IDA”) and MuGard®  Mucoadhesive Oral Wound Rinse, for the management of oral mucositis.
	Currently, our principal source of revenue is from the sale of Feraheme, which was approved for marketing in the U.S. in June 2009 by the U.S. Food and Drug Administration (“FDA”) for use as an IV iron replacement therapy for the treatment of IDA in adult patients with chronic kidney disease (“CKD”). We began selling Feraheme in the U.S. in July 2009 through our own commercial organization, including a specialty sales force. We sell Feraheme to authorized wholesalers and specialty distributors, who in turn, sell Feraheme to healthcare providers who administer Feraheme primarily within hospitals, hematology and oncology centers, and nephrology clinics.
	Outside of the U.S., ferumoxytol has been granted marketing approval in Canada, Switzerland and the European Union (“EU”) for use as an IV iron replacement therapy for the treatment of IDA in adult patients with CKD. In March 2010, we entered into a License, Development and Commercialization Agreement (the “Takeda Agreement”), which was amended in June 2012 (the “Amended Takeda Agreement”) with Takeda Pharmaceutical Company Limited (“Takeda”). Under the Amended Takeda Agreement, Takeda has an exclusive license to market and sell ferumoxytol in Canada, the EU and Switzerland, as well as certain other geographic territories. The European marketing authorization for Rienso in the EU is valid in the 28 EU Member States as well as in Iceland, Liechtenstein and Norway. The trade name for ferumoxytol in Canada is Feraheme and outside of the U.S. and Canada the trade name is Rienso.
	On June 6, 2013 (the “Acquisition Date”) we entered into a License Agreement with PlasmaTech Biopharmaceuticals, Inc. (“PlasmaTech”) (formerly known as Access Pharmaceuticals, Inc.) under which we acquired the U.S. commercial rights to MuGard (“the “MuGard License Agreement”). MuGard was launched in the U.S. by PlasmaTech in 2010 after receiving 510(k) clearance from the FDA and is indicated for the management of oral mucositis/stomatitis (that may be caused by radiotherapy and/or chemotherapy) and all types of oral wounds (mouth sores and injuries), including aphthous ulcers/canker sores and traumatic ulcers, such as those caused by oral surgery or ill-fitting dentures or braces. Under the MuGard License Agreement, we obtained an exclusive, royalty-bearing license, with the right to grant sublicenses, to certain intellectual property rights, including know-how, patents and trademarks, to use, import, offer for sale, sell, manufacture and commercialize MuGard in the U.S. and its territories (the “U.S. Territory”) for the management of all diseases or conditions of the oropharyngeal cavity, including mucositis (“the “MuGard Rights”). Additional details regarding the MuGard License Agreement and the MuGard Rights can be found in Note H, “Business Combination.”
	On September 28, 2014, we entered into a definitive agreement to acquire Lumara Health Inc. (“Lumara”), a privately-held pharmaceutical company specializing in women’s health, for $675.0 million ($600.0 million in cash and $75.0 million in stock) and additional contingent consideration of up to $350.0 million based on the achievement of certain sales milestones. Lumara markets Makena® (hydroxyprogesterone caproate injection), a progestin indicated to reduce the risk of preterm birth in women with a singleton pregnancy who have a history of singleton spontaneous preterm birth. Additional details regarding the definitive agreement with Lumara can be found in Note S, “Subsequent Event.”
	Throughout this Quarterly Report on Form 10-Q, AMAG Pharmaceuticals, Inc. and our consolidated subsidiaries are collectively referred to as “the Company,” “AMAG,” “we,” “us,” or “our.” Unless the context suggests otherwise, references to “Feraheme” refer to both Feraheme (the trade name for ferumoxytol in the U.S. and Canada) and Rienso (the trade name for ferumoxytol in the EU and Switzerland).

Basis_of_Presentation_and_Summ

Basis of Presentation and Summary of Significant Accounting Policies	9 Months Ended
	Sep. 30, 2014
Basis of Presentation and Summary of Significant Accounting Policies	'
Basis of Presentation and Summary of Significant Accounting Policies	'
	B.Basis of Presentation and Summary of Significant Accounting Policies
	Basis of Presentation
	These condensed consolidated financial statements are unaudited and, in the opinion of management, include all adjustments necessary for a fair statement of the financial position and results of operations of the Company for the interim periods presented. Such adjustments consisted only of normal recurring items. The year-end condensed consolidated balance sheet data was derived from audited financial statements, but does not include all disclosures required by accounting principles generally accepted in the United States of America (“GAAP”).
	In accordance with GAAP for interim financial reports and the instructions for Form 10-Q and the rules of the Securities and Exchange Commission, certain information and footnote disclosures normally included in annual financial statements have been condensed or omitted. Our accounting policies are described in the Notes to the Financial Statements in our Annual Report on Form 10-K for the year ended December 31, 2013. Interim results are not necessarily indicative of the results of operations for the full year. These interim financial statements should be read in conjunction with our Annual Report on Form 10-K for the year ended December 31, 2013.
	Use of Estimates and Assumptions
	The preparation of condensed consolidated financial statements in conformity with GAAP requires management to make certain estimates and assumptions that affect the reported amounts of assets, liabilities, revenues and expenses, and the related disclosure of contingent assets and liabilities. The most significant estimates and assumptions are used in, but are not limited to, revenue recognition related to product sales and collaboration agreements, product sales allowances and accruals, assessing investments for potential other-than-temporary impairment, determining the fair values of our investments, assets acquired in a business combination, debt obligations, and contingent consideration, the impairment of long-lived assets, including intangible assets, accrued expenses, and equity-based compensation expense. Actual results could differ materially from those estimates.
	Cash and Cash Equivalents
	Cash and cash equivalents consists principally of cash held in commercial bank accounts, money market funds and U.S. Treasury securities having an original maturity of less than three months. We consider all highly liquid investments with a maturity of three months or less as of the acquisition date to be cash equivalents. At September 30, 2014, substantially all of our cash and cash equivalents were held in either commercial bank accounts or money market funds.
	Principles of Consolidation
	The accompanying condensed consolidated financial statements include our accounts and the accounts of our wholly-owned subsidiaries. All intercompany account balances and transactions between the companies have been eliminated.
	Fair Value Measurements
	Under current accounting standards, fair value is defined as the exchange price that would be received for an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. Valuation techniques used to measure fair value must maximize the use of observable inputs and minimize the use of unobservable inputs.
	Current accounting guidance establishes a hierarchy used to categorize how fair value is measured and which is based on three levels of inputs, of which the first two are considered observable and the third unobservable, as follows:
	Level 1 - Quoted prices in active markets for identical assets or liabilities.
	Level 2 - Inputs other than Level 1 that are observable, either directly or indirectly, such as quoted prices for similar assets or liabilities, quoted prices in markets that are not active, or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities.
	Level 3 - Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities.
	We hold certain assets and liabilities that are required to be measured at fair value on a recurring basis, including our cash equivalents, investments, and contingent consideration.
	Revenue Recognition and Related Sales Allowances and Accruals
	We recognize revenue from the sale of our products as well as license fee and other collaboration revenues, including milestone payments, other product sale revenues, and royalties we receive from our licensees. We recognize revenue in accordance with current accounting guidance related to the recognition, presentation and disclosure of revenue in financial statements, which outlines the basic criteria that must be met to recognize revenue and provides guidance for disclosure of revenue in financial statements. We recognize revenue when:
	Persuasive evidence of an arrangement exists;
	Delivery of product has occurred or services have been rendered;
	The sales price charged is fixed or determinable; and
	Collection is reasonably assured.
	U.S. Feraheme Product Sales, Net
	An analysis of our U.S. Feraheme product sales allowances and accruals for the three and nine months ended September 30, 2014 and 2013 is as follows (in thousands):
		Three Months Ended September 30,
		2014			2013
	Provision for U.S. Feraheme product sales allowances and accruals
	Discounts and chargebacks	$	13,876		$	10,205
	Government and other rebates	4,161			3,044
	Medicaid rebate reserve adjustment	—			(625		)
	Returns	212			265
	Total provision for U.S. Feraheme product sales allowances and accruals	18,249			12,889
	Total gross U.S. Feraheme product sales	$	40,796		$	32,236
	Total provision for U.S. Feraheme product sales allowances and accruals as a percent of total gross U.S. Feraheme product sales	45		%	40		%
		Nine Months Ended September 30,
		2014			2013
	Provision for U.S. Feraheme product sales allowances and accruals
	Discounts and chargebacks	$	37,824		$	26,925
	Government and other rebates	11,300			8,106
	Medicaid rebate reserve adjustment	—			(568		)
	Returns	584			697
	Total provision for U.S. Feraheme product sales allowances and accruals	49,708			35,160
	Total gross U.S. Feraheme product sales	$	111,855		$	87,541
	Total provision for U.S. Feraheme product sales allowances and accruals as a percent of total gross U.S. Feraheme product sales	44		%	40		%
	Consistent with industry practice, we generally offer our wholesalers, specialty distributors and other customers a limited right to return Feraheme based on the product’s expiration date which, once packaged, is currently five years in the U.S. We estimate product returns based on the historical return patterns and known or expected changes in the marketplace. We track actual returns by individual production lots. Returns on lots eligible for credits under our returned goods policy are monitored and compared with historical return trends and rates.
	We expect that wholesalers and healthcare providers will not stock significant inventory due to the cost and expense to store Feraheme. We record an estimate of returns at the time of sale. If necessary, our estimated rate of returns may be adjusted for actual return experience as it becomes available and for known or expected changes in the marketplace. During the nine months ended September 30, 2014, we reduced our reserve for product returns by $0.3 million due to the lapse of the product return period on certain manufactured Feraheme lots. We did not significantly adjust our reserve for product returns during the nine months ended September 30, 2013. To date, returns of Feraheme have been relatively limited; however returns experience may change over time. As we continue to gain more historical experience with actual returns, we may be required to make a future adjustment to our product returns estimate, which would result in a corresponding change to our net product sales in the period of adjustment and could be significant.
	In addition, as part of our sales allowances and accruals, we reserve for estimated Medicaid rebates associated with instances where Medicaid will act as the insurer and for which we are required to pay a statutory rebate to Medicaid. We regularly assess our Medicaid reserve balance and the rate at which we accrue for claims against product sales. We did not adjust our Medicaid reserve balance during the nine months ended September 30, 2014. During the nine months ended September 30, 2013, we revised our estimated Medicaid reserve rate based on actual product-specific rebate claims received since the July 2009 launch of Feraheme, our expectations of state level activities, and estimated rebate claims not yet submitted, which resulted in a $0.6 million reduction of our then estimated Medicaid rebate reserve related to prior period Feraheme sales. This change in estimate was reflected as an increase in our net product sales for the nine months ended September 30, 2013 and resulted in reductions to our gross to net percentage in that period. The reduction of our estimated Medicaid rebate reserve had an impact of $0.03 per basic and diluted share for the nine months ended September 30, 2013. If we determine in future periods that our actual rebate experience is not indicative of expected claims, if our actual claims experience changes, or if other factors affect estimated claims rates, we may be required to adjust our current Medicaid accumulated reserve estimate, which would affect our net product sales in the period of the adjustment and could be significant.
	Concentrations and Significant Customer Information
	Financial instruments which potentially subject us to concentrations of credit risk consist principally of cash, investments, and accounts receivable. As of September 30, 2014, our cash, cash equivalents and investments amounted to approximately $386.2 million. We currently invest our excess cash primarily in U.S. government and agency money market funds, and investments in corporate debt securities, U.S. treasury and government agency securities, and commercial paper. As of September 30, 2014, we had approximately $191.3 million of our total $196.2 million cash and cash equivalents balance invested in institutional money market funds, of which $179.9 million was invested in a single fund.
	Our operations are located solely within the U.S. We are currently focused principally on developing, manufacturing, and commercializing Feraheme and commercializing MuGard. We perform ongoing credit evaluations of our customers and generally do not require collateral. The following table sets forth customers who represented 10% or more of our total revenues for the nine months ended September 30, 2014 and 2013:
		Nine Months Ended September 30,
		2014		2013
	AmerisourceBergen Drug Corporation	39	%	43	%
	McKesson Corporation	24	%	23	%
	Cardinal Health, Inc.	18	%	16	%
	Takeda Pharmaceuticals Company Limited	10	%	11	%
	In addition, approximately 27% and 32% of our end-user demand during the nine months ended September 30, 2014 and 2013, respectively, was generated by members of a single group purchasing organization (“GPO”) with which we have contracted. Revenues from customers outside of the U.S. amounted to approximately 11% of our total revenues for the nine months ended September 30, 2014 and 2013 and were principally related to collaboration revenue recognized in connection with our collaboration agreement with Takeda, which is headquartered in Japan.
	We are currently solely dependent on a single supply chain for our Feraheme drug substance and finished drug product. We would be exposed to a significant loss of revenue from the sale of Feraheme if our suppliers and/or manufacturers cannot fulfill demand for any reason.

Investments

Investments	9 Months Ended
	Sep. 30, 2014
Investments	'
Investments	'
	C.Investments
	As of September 30, 2014 and December 31, 2013, our investments equaled $190.1 million and $186.8 million, respectively, and consisted of securities classified as available-for-sale in accordance with accounting standards which provide guidance related to accounting and classification of certain investments in debt and equity securities.
	The following is a summary of our investments as of September 30, 2014 and December 31, 2013 (in thousands):
		September 30, 2014
				Gross		Gross			Estimated
		Amortized		Unrealized		Unrealized			Fair
		Cost		Gains		Losses			Value
	Corporate debt securities
	Due in one year or less	$	47,057	$	56	$	(5	)	$	47,108
	Due in one to three years	87,529		100		(147		)	87,482
	U.S. treasury and government agency securities
	Due in one year or less	22,978		27		—			23,005
	Due in one to three years	30,986		32		(25		)	30,993
	Commercial paper
	Due in one year or less	1,500		—		—			1,500
	Total investments	$	190,050	$	215	$	(177	)	$	190,088
		December 31, 2013
				Gross		Gross			Estimated
		Amortized		Unrealized		Unrealized			Fair
		Cost		Gains		Losses			Value
	Corporate debt securities
	Due in one year or less	$	42,609	$	44	$	(4	)	$	42,649
	Due in one to three years	91,443		137		(106		)	91,474
	U.S. treasury and government agency securities
	Due in one year or less	18,526		19		—			18,545
	Due in one to three years	34,123		37		(25		)	34,135
	Total investments	$	186,701	$	237	$	(135	)	$	186,803
	Impairments and Unrealized Gains and Losses on Investments
	We did not recognize any other-than-temporary impairment losses in our condensed consolidated statements of operations related to our securities during any of the three or nine month periods ended September 30, 2014 and 2013. We considered various factors, including our current intentions to sell, the length of time that each security was in an unrealized loss position and our ability and intent to hold these securities until the recovery of their amortized cost basis occurs. As of September 30, 2014, an insignificant portion of our investments has been in an unrealized loss position for more than one year. Future events may occur, or additional information may become available, which may cause us to identify credit losses where we do not expect to receive cash flows sufficient to recover the entire amortized cost basis of a security and which may necessitate the recording of future realized losses on securities in our portfolio. Significant losses in the estimated fair values of our investments could have a material adverse effect on our earnings in future periods.
	Realized Gains and Losses on Investments
	Gains and losses are determined on the specific identification method. Realized gains were insignificant during the three and nine months ended September 30, 2014 and 2013.

Fair_Value_Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2014
Fair Value Measurements	'
Fair Value Measurements	'
	D.Fair Value Measurements
	The following tables represent the fair value hierarchy as of September 30, 2014 and December 31, 2013 for those assets and liabilities that we measure at fair value on a recurring basis (in thousands):
		Fair Value Measurements at September 30, 2014 Using:
					Quoted Prices in Active		Significant Other		Significant
					Markets for Identical		Observable Inputs		Unobservable
					Assets				Inputs
		Total			(Level 1)		(Level 2)		(Level 3)
	Assets:
	Money market funds	$	191,258		$	191,258	$	—	$	—
	Corporate debt securities	134,590			—		134,590		—
	U.S. treasury and government agency securities	53,998			—		53,998		—
	Commercial paper	1,500			—		1,500		—
	Total Assets	$	381,346		$	191,258	$	190,088	$	—
	Liabilities:
	Acquisition-related contingent consideration	$	11,848		—		—		11,848
	Total Liabilities	$	11,848		$	—	$	—	$	11,848
		Fair Value Measurements at December 31, 2013 Using:
					Quoted Prices in Active		Significant Other		Significant
					Markets for Identical		Observable Inputs		Unobservable
					Assets				Inputs
		Total			(Level 1)		(Level 2)		(Level 3)
	Assets:
	Money market funds	$	18,767		$	18,767	$	—	$	—
	Corporate debt securities	134,123			—		134,123		—
	U.S. treasury and government agency securities	52,680			—		52,680		—
	Total Assets	$	205,570		$	18,767	$	186,803	$	—
	Liabilities:
	Acquisition-related contingent consideration	$	14,550		$	—	$	—	$	14,550
	Total Liabilities	$	14,550		$	—	$	—	$	14,550
	With the exception of our money market funds and our acquisition-related contingent consideration, the fair value of our investments is primarily determined from independent pricing services. Independent pricing services normally derive security prices from recently reported trades for identical or similar securities, making adjustments based upon other significant observable market transactions. At the end of each reporting period, we perform quantitative and qualitative analyses of prices received from third parties to determine whether prices are reasonable estimates of fair value. After completing our analyses, we did not adjust or override any fair value measurements provided by our pricing services as of September 30, 2014. In addition, there were no transfers or reclassifications of any securities between Level 1 and Level 2 during the nine months ended September 30, 2014.
	Contingent consideration
	We accounted for the acquisition of the MuGard Rights as a business combination under the acquisition method of accounting. Additional details regarding the MuGard License Agreement and the MuGard Rights can be found in Note H, “Business Combination.”  The fair value measurements of contingent consideration obligations arising from business combinations are determined using unobservable inputs (“Level 3”). These inputs include (a) the estimated amount and timing of projected cash flows; (b) the probability of the achievement of the factors on which the contingency is based; and (c) the risk-adjusted discount rate used to present value the probability-weighted cash flows. Significant increases or decreases in any of those inputs in isolation could result in a significantly lower or higher fair value measurement.
	The following table presents a reconciliation of contingent consideration obligations related to our acquisition of the MuGard Rights measured on a recurring basis using Level 3 inputs as of September 30, 2014 (in thousands):
	Balance as of December 31, 2013	$	14,550
	Payments made	(186		)
	Adjustments to fair value of contingent consideration	(2,535		)
	Other adjustments	19
	Balance as of September 30, 2014	$	11,848
	During the three months ended September 30, 2014, we revised our forecast of total projected net sales for MuGard and reassessed the fair value of the contingent consideration liability related to the MuGard Rights. As a result, we reduced our contingent consideration liability by $3.7 million and $2.5 million for the three and nine months ended September 30, 2014, respectively. This adjustment is included in selling, general and administrative expenses in our condensed consolidated statements of operations. The $3.7 million adjustment to our contingent consideration liability had an impact of increasing our net income (loss) by $0.17 and $0.16 per basic and diluted share for the three months ended September 30, 2014, respectively, and the $2.5 million adjustment to our contingent consideration liability had an impact of increasing our net income (loss) by $0.12 per basic and diluted share for the nine months ended September 30, 2014. As of September 30, 2014, we estimate that the undiscounted royalty amounts we could pay under the MuGard License Agreement may range from $20.0 million to $28.0 million over a ten year period beginning on the Acquisition Date, which is our best estimate of the period over which we expect the majority of the asset’s cash flows to be derived. This measure is based on significant Level 3 inputs not observable in the market. Key assumptions include a discount rate of approximately 15%. We have classified $0.7 million of the contingent consideration as a short-term liability, which was included in accrued expenses in our condensed consolidated balance sheet as of September 30, 2014.
	Debt
	In February 2014, we issued $200.0 million of 2.5% convertible senior notes due February 15, 2019 (the “Convertible Notes”). Interest is payable semi-annually in arrears on February 15 and August 15 of each year, beginning on August 15, 2014. As of September 30, 2014, the fair value of our Convertible Notes was $271.2 million, which differs from their carrying values. The fair value of our Convertible Notes is influenced by interest rates and our stock price and stock price volatility and is determined by prices for the Convertible Notes observed in market trading, which are Level 2 inputs. In addition, in connection with the pricing of the Convertible Notes, we entered into convertible bond hedge transactions (“convertible bond hedges”) and separate warrant transactions (“warrants”), as discussed in more detail in Note P, “Debt.”

Accounts_Receivable_Net

Accounts Receivable, Net	9 Months Ended
	Sep. 30, 2014
Accounts Receivable, Net	'
Accounts Receivable, Net	'
	E.Accounts Receivable, Net
	Our net accounts receivable were $10.9 million and $6.8 million as of September 30, 2014 and December 31, 2013, respectively, and primarily represented amounts due from wholesalers and distributors to whom we sell Feraheme directly. Accounts receivable are recorded net of reserves for estimated chargeback obligations, prompt payment discounts and any allowance for doubtful accounts.
	Customers which represented greater than 10% of our accounts receivable balances as of September 30, 2014 and December 31, 2013 were as follows:
		September 30, 2014		December 31, 2013
	AmerisourceBergen Drug Corporation	51	%	43	%
	McKesson Corporation	26	%	29	%
	Cardinal Health, Inc.	15	%	19	%

Inventories

Inventories	9 Months Ended
	Sep. 30, 2014
Inventories	'
Inventories	'
	F.Inventories
	Our major classes of inventories were as follows as of September 30, 2014 and December 31, 2013 (in thousands):
		September 30, 2014		December 31, 2013
	Raw materials	$	4,341	$	3,157
	Work in process	7,158		8,322
	Finished goods	8,081		5,738
	Total inventories	$	19,580	$	17,217
	During the nine months ended September 30, 2014, we expensed $0.7 million of commercial inventory, which we determined would be solely used in development activities at our third-party suppliers, which we have recorded in research and development expenses. In addition, during the nine months ended September 30, 2014, we expensed $0.4 million of commercial inventory deemed no longer saleable, which we have recorded in cost of goods sold.

Property_and_Equipment_Net

Property and Equipment, Net	9 Months Ended
	Sep. 30, 2014
Property and Equipment, Net	'
Property and Equipment, Net	'
	G.Property and Equipment, Net
	Property and equipment consisted of the following as of September 30, 2014 and December 31, 2013 (in thousands):
		September 30, 2014			December 31, 2013
	Furniture and fixtures	$	1,509		$	1,536
	Leasehold improvements	430			430
	Laboratory and production equipment	492			376
		2,431			2,342
	Less - accumulated depreciation	(849		)	(496		)
	Property and equipment, net	$	1,582		$	1,846

Business_Combination

Business Combination	9 Months Ended
	Sep. 30, 2014
Business Combination	'
Business Combination	'
	H.Business Combination
	As part of our strategy to expand our portfolio with additional commercial-stage products, in June 2013, we entered into the MuGard License Agreement pursuant to which we obtained an exclusive, royalty-bearing license, with the right to grant sublicenses, to certain intellectual property rights, including know-how, patents and trademarks, to use, import, offer for sale, sell, manufacture and commercialize MuGard in the U.S. Territory for the management of all diseases or conditions of the oropharyngeal cavity, including mucositis.
	In consideration for the license, we paid PlasmaTech an upfront payment of $3.3 million in June 2013. We are required to pay royalties to PlasmaTech on net sales of MuGard until the later of (a) the expiration of the licensed patents or (b) the tenth anniversary of the first commercial sale of MuGard under the MuGard License Agreement in the U.S. Territory (the “Royalty Term”). These tiered, double-digit royalty rates decrease for any part of the Royalty Term occurring after the expiration of the licensed patents and are subject to off-set against certain of our expenses. After the expiration of the Royalty Term, the license shall become a fully paid-up, royalty-free and perpetual license in the U.S. Territory. In addition to making an upfront payment of $3.3 million, we also acquired $0.2 million of existing MuGard inventory from PlasmaTech, which was included in our condensed consolidated balance sheet as of the Acquisition Date.
	We did not assume any pre-existing liabilities related to the MuGard business, contingent or otherwise, arising prior to the Acquisition Date. We accounted for the acquisition of the MuGard Rights as a business combination under the acquisition method of accounting. The following table summarizes the total consideration for the MuGard Rights (in thousands):
	Consideration:
	Cash	$	3,434
	Acquisition-related contingent consideration	13,700
	Total consideration	$	17,134
	The $17.1 million total consideration includes the estimated fair value of the contingent consideration at the Acquisition Date.
	The following table summarizes the estimated fair values of the assets acquired related to the business combination as of the Acquisition Date (in thousands):
	Assets Acquired:
	MuGard intangible asset	$	16,893
	Inventory	241
	Net identifiable assets acquired	$	17,134
	Transaction costs were not included as a component of consideration transferred and were expensed as incurred. We incurred approximately $0.8 million of acquisition-related costs in the nine months ended September 30, 2013. These costs were primarily related to professional and legal fees and were included in selling, general and administrative expenses in our condensed consolidated statements of operations for the nine months ended September 30, 2013.

Intangible_Assets_Net

Intangible Assets, Net	9 Months Ended
	Sep. 30, 2014
Intangible Assets, Net	'
Intangible Assets, Net	'
	I.Intangible Assets, Net
	In June 2013, we acquired the MuGard Rights from PlasmaTech and recorded $16.9 million to finite-lived intangible assets based on the estimated fair value of the MuGard Rights as of the Acquisition Date.
	We amortize the MuGard Rights using an economic consumption model over ten years from the Acquisition Date, which represents our best estimate of the period over which we expect the majority of the asset’s cash flows to be derived. We believe this is the best approximation of the period over which we will derive the majority of value of the MuGard Rights. We recorded approximately $0.1 million and $0.2 million of amortization related to the MuGard Rights in cost of product sales in our condensed consolidated statements of operations for the three and nine months ended September 30, 2014, respectively, and as a result, our intangible asset related to the MuGard Rights was $16.6 million as of September 30, 2014.
	Intangible assets are reviewed for impairment at least annually and whenever facts or circumstances suggest that the carrying value of these assets may not be recoverable. Our policy is to identify and record impairment losses, if necessary, on intangible assets when events and circumstances indicate that the assets might be impaired and the undiscounted cash flows estimated to be generated by those assets are less than the carrying amounts of those assets. We did not record any impairment losses in the nine months ended September 30, 2014 and 2013.

Income_Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2014
Income Taxes	'
Income Taxes	'
	J.Income Taxes
	Deferred tax assets and deferred tax liabilities are recognized based on temporary differences between the financial reporting and tax basis of assets and liabilities using future enacted rates. A valuation allowance is recorded against deferred tax assets if it is more likely than not that some or all of the deferred tax assets will not be realized.
	For the nine months ended September 30, 2014 and 2013, we did not recognize any tax expense or benefit due to our continued net operating loss position. Due to the uncertainty surrounding the realization of favorable tax attributes in future tax returns, we have recorded a full valuation allowance against our otherwise recognizable net deferred tax assets.
	The interest expense related to the Convertible Notes is deductible for income tax purposes, subject to certain limitations.
	On September 26, 2014, we adopted an amendment to our Rights Agreement to help preserve our substantial tax assets associated with net operating loss carry forwards (“NOLs”) and other tax benefits by deterring certain stockholders from increasing their percentage ownership in our stock (the “NOL Amendment”). The NOL Amendment is discussed in more detail in Note Q, “Stockholders’ Equity.”

Accumulated_Other_Comprehensiv

Accumulated Other Comprehensive Loss	9 Months Ended
	Sep. 30, 2014
Accumulated Other Comprehensive Loss	'
Accumulated Other Comprehensive Loss	'
	K.Accumulated Other Comprehensive Loss
	The changes in accumulated other comprehensive loss, net of tax, for the three and nine months ended September 30, 2014 and 2013 consisted of the following (in thousands):
		Three Months Ended September 30,						Nine Months Ended September 30,
		2014			2013			2014			2013
	Beginning Balance	$	(3,259	)	$	(3,935	)	$	(3,491	)	$	(3,247	)
	Other comprehensive income (loss) before reclassifications	(305		)	399			(76		)	(310		)
	Gain reclassified from other accumulated comprehensive loss	9			—			12			21
	Ending Balance	$	(3,555	)	$	(3,536	)	$	(3,555	)	$	(3,536	)
	The amounts reclassified from other comprehensive loss for the three and nine months ended September 30, 2014, primarily represented realized gains on investments, which are included in our condensed consolidated statement of operations under “Gains on investments, net.”

Basic_and_Diluted_Net_Income_L

Basic and Diluted Net Income (Loss) per Share	9 Months Ended
	Sep. 30, 2014
Basic and Diluted Net Income (Loss) per Share	'
Basic and Diluted Net Income (Loss) per Share	'
	L.Basic and Diluted Net Income (Loss) per Share
	We compute basic net income (loss) per share by dividing net income (loss) by the weighted average number of common shares outstanding during the relevant period. Diluted net income per common share has been computed by dividing net income by the diluted number of shares outstanding during the period. Except where the result would be antidilutive to net income, diluted net income per common share has been computed assuming the conversion of the Convertible Notes, the exercise of outstanding stock options, and the vesting of restricted stock units (“RSUs”).
	As we have a choice to settle the conversion obligation under the Convertible Notes in cash, shares or any combination of the two, we currently intend to settle the principal value of the Convertible Notes in cash and the excess conversion premium in shares. The dilutive effect of the conversion premium is reflected in the calculation of diluted earnings per share as if it were a freestanding written call option on our shares. The impact of the conversion premium has been considered in the calculation of diluted net income per share by applying the closing price of our common stock on September 30, 2014 to calculate the number of shares issuable under the conversion premium. The principal value of the Convertible Notes is not included in the calculation of diluted income per share, as we intend to settle this in cash. In February 2014, in connection with the issuance of the Convertible Notes, we entered into convertible bond hedges. The convertible bond hedges are not included for purposes of calculating the number of diluted shares outstanding, as their effect would be anti-dilutive. The convertible bond hedges are generally expected, but not guaranteed, to reduce the potential dilution and/or offset the cash payments we are required to make upon conversion of the Convertible Notes. See Note P, “Debt,” for additional information.
	The dilutive effect of the stock options and RSUs has been calculated using the treasury stock method.
	The components of basic and diluted net income (loss) per share for the three and nine months ended September 30, 2014 and 2013 were as follows (in thousands, except per share data):
		Three Months Ended September 30,						Nine Months Ended September 30,
		2014			2013			2014			2013
	Net income (loss)	$	1,458		$	(145	)	$	(7,191	)	$	(5,948	)
	Weighted average common shares outstanding	21,984			21,691			21,912			21,613
	Effect of dilutive securities:
	Stock options and restricted stock units	369			—			—			—
	Convertible 2.5% senior notes	1,114			—			—			—
	Shares used in calculating dilutive net income (loss) per share	23,467			21,691			21,912			21,613
	Net income (loss) per share:
	Basic	$	0.07		$	(0.01	)	$	(0.33	)	$	(0.28	)
	Diluted	$	0.06		$	(0.01	)	$	(0.33	)	$	(0.28	)
	As discussed above in Note D, “Fair Value Measurements,” we reduced our contingent consideration liability by $3.7 million and $2.5 million for the three and nine months ended September 30, 2014, respectively, in connection with our reassessment of the fair value of the contingent consideration liability relating to our acquisition of the MuGard Rights. The $3.7 million adjustment to our contingent consideration liability increased our net income (loss) by $0.17 and $0.16 per basic and diluted share, respectively, for the three months ended September 30, 2014 and the $2.5 million adjustment to our contingent consideration liability increased our net income (loss) by $0.12 per basic and diluted share for the nine months ended September 30, 2014.
	The following table sets forth the potential common shares issuable upon the exercise of outstanding options, the vesting of RSUs and warrants (prior to consideration of the treasury stock method), which were excluded from our computation of diluted net income (loss) per share because their inclusion would have been anti-dilutive:
		Three Months Ended September 30,				Nine Months Ended September 30,
		2014		2013		2014		2013
	Options to purchase shares of common stock	2,013		2,717		3,081		2,717
	Shares of common stock issuable upon the vesting of restricted stock units	289		497		760		497
	Warrants	7,382		—		7,382		—
	Total	9,684		3,214		11,223		3,214
	During the three and nine months ended September 30, 2014, the average common stock price was below the exercise price of the warrants.

EquityBased_Compensation

Equity-Based Compensation	9 Months Ended
	Sep. 30, 2014
Equity-Based Compensation	'
Equity-Based Compensation	'
	M.Equity-Based Compensation
	We currently maintain two equity compensation plans, our Third Amended and Restated 2007 Equity Incentive Plan (the “2007 Plan”) and our Amended and Restated 2000 Stock Plan (the “2000 Plan”) (under which we no longer grant awards). During the nine months ended September 30, 2014, we also granted equity to certain newly hired executive officers through inducement grants outside of these plans.
	Third Amended and Restated 2007 Equity Incentive Plan
	Our 2007 Plan was originally approved by our stockholders in November 2007. In each of May 2009, May 2010, and May 2013 our stockholders approved proposals to amend and restate our 2007 Plan to, among other things, increase the number of shares authorized for issuance thereunder by 600,000, 800,000 and 1,100,000 shares, respectively.
	As of September 30, 2014, we have granted options and RSUs covering 7,523,252 shares of common stock under our 2007 Plan, of which 3,014,117 stock options and 688,824 RSUs have expired or terminated, and of which 314,295 options have been exercised and 527,546 shares of common stock have been issued pursuant to RSUs that became fully vested. The number of options and RSUs outstanding under this plan as of September 30, 2014, was 2,423,758 and 554,712, respectively. The remaining number of shares available for future grants as of September 30, 2014 was 1,579,800, not including shares subject to outstanding awards under the 2000 Plan, which will be added to the total number of shares available for issuance under the 2007 Plan to the extent that such awards expire or terminate for any reason prior to exercise. All outstanding stock options granted under our 2007 Plan have an exercise price equal to the closing price of a share of our common stock on the grant date and have either a seven or ten-year term.
	Amended and Restated 2000 Stock Plan
	Our 2000 Plan provided for the grant of options and other equity-based awards to our directors, officers, employees and consultants. As of September 30, 2014, we have granted stock options and RSUs covering 2,182,700 shares of common stock under the 2000 Plan, of which 1,034,339 stock options and 1,500 RSUs have expired or terminated, and of which 1,052,045 stock options have been exercised and 42,500 shares of common stock have been issued pursuant to RSUs that became fully vested. The remaining number of shares underlying outstanding stock options which were issued pursuant to our 2000 Plan as of September 30, 2014, was 52,316. There were no remaining RSUs which were issued pursuant to our 2000 Plan as of September 30, 2014. All outstanding stock options granted under the 2000 Plan have an exercise price equal to the closing price of our common stock on the grant date and have a ten year term. In November 2007, the 2000 Plan was succeeded by our 2007 Plan and, accordingly, no further grants may be made under this plan. Any shares that remained available for issuance under the 2000 Plan as of the date of adoption of the 2007 Plan are included in the number of shares that may be issued under the 2007 Plan. Any shares subject to outstanding awards granted under the 2000 Plan that expire or terminate for any reason prior to exercise will be added to the total number of shares available for issuance under the 2007 Plan.
	Other Equity Compensation Grants
	In August 2014, we granted certain members of our senior management performance-based RSUs covering a maximum of 195,000 shares of common stock, which will be earned, if at all, based on the achievement of certain (a) targets based upon the calculated value expected to be realized with respect to certain business and corporate development transactions and (b) stock price minimums, during the 30-month period ending January 2, 2017, measured as of January 4, 2016 and January 2, 2017. Fifty percent of the RSU grant that is earned through January 4, 2016 shall vest as of such date, and 100% of the RSU grant that is earned through January 2, 2017 (less the portion previously vested) shall vest as of January 2, 2017, subject to the continued employment of the grantee through each such date. In the event that the minimum conditions of these RSUs are not met as of the measurement dates, none of the RSUs will vest. The maximum total fair value of these RSUs is $6.3 million, which will be recognized to expense over a period of approximately three years from the date the vesting conditions outlined in these grants are deemed probable, net of any estimated and actual forfeitures.
	During the nine months ended September 30, 2014, our Board granted options to purchase 165,000 shares of our common stock and 65,300 RSUs to certain new-hire members of our senior management to induce them to accept employment with us. The options were granted at an exercise price equal to the fair market value of a share of our common stock on the respective grant dates and will be exercisable in four equal annual installments beginning on the first anniversary of the respective grant dates. The RSU grants will vest in four equal annual installments beginning on the first anniversary of the respective grant dates. The foregoing grants were made pursuant to inducement grants outside of our 2007 Plan as permitted under the NASDAQ Global Market rules. We assessed the terms of these awards and determined there was no possibility that we would have to settle these awards in cash and therefore, equity accounting was applied. During 2012, we began issuing grants pursuant to inducement grants outside of our 2007 Plan as permitted under the NASDAQ Global Market rules. Since then, we have issued a total of 1,015,300 shares of common stock pursuant to inducement grants outside of our 2007 Plan, of which 101,250 stock options and 41,250 RSUs have been forfeited and of which 28,750 options have been exercised and 33,750 shares of common stock have been issued pursuant to RSUs that became fully vested.
	Equity-based compensation expense
	Equity-based compensation expense for the three and nine months ended September 30, 2014 and 2013 consisted of the following (in thousands):
		Three Months Ended September 30,				Nine Months Ended September 30,
		2014		2013		2014		2013
	Cost of product sales	$	32	$	25	$	89	$	83
	Research and development	466		337		1,274		1,634
	Selling, general and administrative	1,448		1,303		4,790		4,169
	Total equity-based compensation expense	$	1,946	$	1,665	$	6,153	$	5,886
	We reduce the compensation expense being recognized to account for estimated forfeitures, which we estimate based primarily on historical experience, adjusted for unusual events such as corporate restructurings, which may result in higher than expected turnover and forfeitures. Under current accounting guidance, forfeitures are estimated at the time of grant and revised, if necessary, in subsequent periods if actual forfeitures differ from those estimates.

Commitments_and_Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2014
Commitments and Contingencies	'
Commitments and Contingencies	'
	N.Commitments and Contingencies
	Legal Proceedings
	We accrue a liability for legal contingencies when we believe that it is both probable that a liability has been incurred and we can reasonably estimate the amount of the loss. We review these accruals and adjust them to reflect ongoing negotiations, settlements, rulings, advice of legal counsel and other relevant information. To the extent new information is obtained and our views on the probable outcomes of claims, suits, assessments, investigations or legal proceedings change, changes in our accrued liabilities would be recorded in the period in which such determination is made. For the matters referenced below, unless otherwise noted, the liability is not probable or the amount cannot be reasonably estimated and, therefore, accruals have not been made. In addition, in accordance with the relevant authoritative guidance, for any matters in which the likelihood of material loss is at least reasonably possible, we will provide disclosure of the possible loss or range of loss. If a reasonable estimate cannot be made, however, we will provide disclosure to that effect.
	A purported class action complaint was originally filed on March 18, 2010 in the U.S. District Court for the District of Massachusetts, entitled Silverstrand Investments et. al. v. AMAG Pharm., Inc., et. al., Civil Action No. 1:10-CV-10470-NMG, and was amended on September 15, 2010 and on December 17, 2010. The second amended complaint (“SAC”), filed on December 17, 2010 alleged that we and our former President and Chief Executive Officer, former Chief Financial Officer, the then-members of our Board, and certain underwriters in our January 2010 offering of common stock violated certain federal securities laws, specifically Sections 11 and 12(a)(2) of the Securities Act of 1933, as amended, and that our former President and Chief Executive Officer and former Chief Financial Officer violated Section 15 of such Act, respectively, by making certain alleged omissions in a registration statement filed in January 2010. The plaintiffs sought unspecified damages on behalf of a purported class of purchasers of our common stock pursuant to our common stock offering on or about January 21, 2010. On August 11 and 15, 2011, respectively, the District Court issued an Opinion and Order dismissing the SAC with prejudice for failure to state a claim upon which relief could be granted. On September 14, 2011, the plaintiffs filed a Notice of Appeal to the U.S. Court of Appeals for the First Circuit (the “Court of Appeals”). The Court of Appeals heard oral argument on May 11, 2012. On February 4, 2013, the Court of Appeals affirmed in part and reversed in part the District Court’s Opinion and Order and remanded the case to the District Court. On February 19, 2013, we filed a Petition for Panel Rehearing and Rehearing En Banc, which was denied on March 15, 2013. On March 22, 2013, we filed a Motion to Stay the Mandate remanding the case to the District Court pending review by the U.S. Supreme Court of the Court of Appeals’ February 4, 2013 decision. The Court of Appeals granted the Motion to Stay the Mandate on April 8, 2013. On June 13, 2013, we filed a Petition for a Writ of Certiorari (the “Petition”) with the U.S. Supreme Court seeking review of the Court of Appeal’s decision and to have that decision overturned. On October 7, 2013 the U.S. Supreme Court denied our Petition, resulting in the case’s return to the District Court for further proceedings relative to the SAC’s surviving claims. On November 6, 2013, we filed a renewed Motion to Dismiss the SAC’s surviving claims. On December 6, 2013, the plaintiffs filed a brief in opposition to our Motion to Dismiss and we filed a reply brief in support of our Motion on December 27, 2013. On April 7, 2014, the District Court denied our renewed Motion to Dismiss. On May 7, 2014, the parties filed a joint status report with the District Court in advance of a status conference held on May 14, 2014. All defendants filed answers and affirmative defenses to the pending complaint on May 19, 2014. On June 6, 2014, the parties requested the District Court to stay the proceedings, which the Court allowed on June 9, 2014. On September 12, 2014, we and the other defendants entered into a stipulation of settlement that will resolve the class action securities lawsuit. Pursuant to the stipulation of settlement, and in exchange for a release of all claims by the class members, among others, and dismissal of the lawsuit with prejudice, we have agreed to cause our insurer to pay eligible class members and their attorneys a total of $3.75 million. On October 2, 2014, the U.S. District Court preliminarily approved the settlement, and potential class members have been notified of the proposed settlement and the procedures by which they can seek to recover from the settlement fund, object to the settlement or request to be excluded from the settlement class. A settlement hearing has been scheduled for January 20, 2015, at which time the stipulation of settlement will be subject to final approval by the U.S. District Court. We have recorded the $3.75 million settlement amount in prepaid and other current assets and a corresponding amount in accrued expenses on our condensed consolidated balance sheet as of September 30, 2014, as the settlement amount will be fully covered by our insurance carrier. There was no impact to our condensed consolidated statement of operations for the nine months ended September 30, 2014.
	In July 2010, Sandoz GmbH (“Sandoz”) filed with the European Patent Office (the “EPO”) an opposition to a previously issued patent which covers ferumoxytol in EU jurisdictions. In October 2012, at an oral hearing, the Opposition Division of the EPO revoked this patent. In December 2012, our notice of appeal of that decision was recorded with the EPO, which also suspended the revocation of our patent. On May 13, 2013, we filed a statement of grounds of appeal and on September 27, 2013, Sandoz filed a response to that statement. We filed a reply to that response on March 17, 2014 and oral proceedings for the appeal is scheduled for June 16, 2015. We will continue to defend the validity of this patent throughout the appeals process, which we expect to take two to three years. However, in the event that we do not experience a successful outcome from the appeals process, under EU regulations ferumoxytol would still be entitled to eight years of data protection and ten years of market exclusivity from the date of approval, which we believe would create barriers to entry for any generic version of ferumoxytol into the EU market until sometime between 2020 and 2022. This decision had no impact on our revenues for the nine months ended September 30, 2014. However, any future unfavorable outcome in this matter could negatively affect the magnitude and timing of future revenues, including royalties and milestone payments we may receive from Takeda pursuant to our collaboration agreement with Takeda. We do not expect to incur any related liability regardless of the outcome of the appeal and therefore have not recorded any liability as of September 30, 2014. We continue to believe the patent is valid and intend to vigorously appeal the decision.
	We may periodically become subject to other legal proceedings and claims arising in connection with ongoing business activities, including claims or disputes related to patents that have been issued or that are pending in the field of research on which we are focused. Other than the above actions, we are not aware of any material claims against us at September 30, 2014. We expense legal costs as they are incurred.

Collaborative_Agreements

Collaborative Agreements	9 Months Ended
	Sep. 30, 2014
Collaborative Agreements	'
Collaborative Agreements	'
	O.Collaborative Agreements
	Our commercial strategy includes the formation of collaborations with other pharmaceutical companies to facilitate the sale and distribution of Feraheme, primarily outside of the U.S., as well as expanding our portfolio through the in-license or acquisition of additional pharmaceutical products or companies, including revenue-generating commercial products and late-stage development assets. As of September 30, 2014, we were a party to the following collaborations:
	Takeda
	In March 2010, we entered into the Takeda Agreement with Takeda under which we granted exclusive rights to Takeda to develop and commercialize Feraheme as a therapeutic agent in Europe, certain Asia-Pacific countries (excluding Japan, China and Taiwan), the Commonwealth of Independent States, Canada, India and Turkey. In June 2012, we entered into the Amended Takeda Agreement, which removed the Commonwealth of Independent States from the territories under which Takeda has the exclusive rights to develop and commercialize Feraheme. In addition, the Amended Takeda Agreement modified the timing and pricing arrangements under a supply agreement to be entered into between us and Takeda, and which was entered into in February 2014 and discussed below. The terms of the Amended Takeda Agreement related to primary and secondary manufacturing for drug substance and drug product, certain patent-related provisions, and the re-allocation of certain of the agreed-upon milestone payments. We analyzed the Amended Takeda Agreement and determined that the amended terms did not result in a material modification of the original Takeda Agreement (and thus did not require us to change our accounting model) because (a) there were no changes to the deliverables under the original Takeda Agreement as a result of the amendment, and (b) the change in arrangement consideration as a result of the amendment was not quantitatively material in relation to the total arrangement consideration.
	In connection with the execution of the original Takeda Agreement, we received a $60.0 million upfront payment from Takeda in April 2010, which we recorded as deferred revenue, as well as approximately $1.0 million reimbursed to us during 2010 for certain expenses incurred prior to entering the agreement, which we considered an additional upfront payment. Because we cannot reasonably estimate the total level of effort required to complete the obligations under the combined deliverable, we are recognizing the entire $60.0 million upfront payment, the $1.0 million reimbursed to us in 2010, as well as any non-substantive milestone payments that are achieved into revenues on a straight-line basis over a period of ten years from March 31, 2010, the date on which we originally entered the Takeda Agreement, which represents the then-current patent life of Feraheme and our best estimate of the period over which we will substantively perform our obligations. We continue to believe that the then-current patent life of Feraheme is our best estimate of the period over which we will substantively perform our obligations under this agreement.
	In addition, the remaining milestone payments we may be entitled to receive under the Amended Takeda Agreement could over time equal up to $186.0 million. For any milestone payments we may receive based upon the approval by certain regulatory agencies, we have determined that these will be deemed substantive milestones and, therefore, will be accounted for as revenue in the period in which they are achieved. We have also determined that any non-substantive milestone payments will be accounted for in accordance with our revenue attribution method for the upfront payment, as described above. During the three and nine months ended September 30, 2014, we recorded $2.0 million and $5.9 million, respectively, in revenues associated with the amortization of the upfront payments in license fee and other collaboration revenues in our condensed consolidated statement of operations. As of September 30, 2014, we had approximately $43.4 million remaining in deferred revenues related to the $61.0 million in upfront payments and the $18.0 million in non-substantive milestone payments previously received from Takeda, of which $7.9 million was classified as short-term and $35.5 million was classified as long-term. Any potential non-substantive milestone payments that may be received in the future will be recognized as revenue on a cumulative catch up basis when they become due and payable.
	Under the terms of the Amended Takeda Agreement, Takeda is responsible for reimbursing us for certain out-of-pocket regulatory and clinical trial supply costs associated with carrying out our regulatory and clinical research activities under the collaboration agreement. Because we are acting as the principal in carrying out these services, any reimbursement payments received from Takeda are recorded in license fee and other collaboration revenues in our condensed consolidated statement of operations to match the costs that we incur during the period in which we perform those services. We recorded $0.2 million and $0.5 million for the three and nine months ended September 30, 2014, respectively, associated with other reimbursement revenues received from Takeda.
	At the time of shipment, we defer recognition of all revenue for Feraheme sold to Takeda in our condensed consolidated balance sheets. We recognize revenues from product sales to Takeda, the related cost of goods sold, and any royalty revenues due from Takeda, in our condensed consolidated statement of operations at the time Takeda reports to us that sales have been made to its customers. During the three and nine months ended September 30, 2014, we recognized $0.3 million and $0.7 million, respectively, in product sales and royalty revenue related to the Amended Takeda Agreement and we have included this revenue in other product sales and royalties in our condensed consolidated statement of operations. As of September 30, 2014, we had approximately $2.7 million in deferred revenue related to product shipped to Takeda but not yet sold through to Takeda’s customers, of which $1.5 million was classified as short-term and $1.2 million was classified as long-term. In addition, we had $2.4 million in deferred cost of product sales, of which $1.4 million was classified as short-term and $1.0 million was classified as long-term. These deferred revenue and deferred cost of product sales are recorded in our condensed consolidated balance sheet as of September 30, 2014.
	In February 2014, we entered into a Supply Agreement with Takeda pursuant to which we sell Feraheme to Takeda to meet Takeda’s requirements for commercial use of Feraheme in the licensed territory. Under the Supply Agreement, Takeda is obligated to periodically provide us with demand forecasts of Takeda’s future Feraheme requirements, which will direct the forecasting and ordering process as well as our supply obligations. Takeda may order Feraheme for commercial use in excess of the forecasts, which we agreed to use commercially reasonable efforts to supply. In addition, the Supply Agreement provides the minimum quantity of Feraheme that shall be ordered in each purchase order for commercial supply. Takeda shall have the right to use the Feraheme ordered under the Supply Agreement for clinical use, provided that the product be subject to all of the terms of the Supply Agreement, including commercial specifications. Takeda shall be solely responsible for labeling and packaging vials of the product in accordance with the terms of the Supply Agreement and the Amended Takeda Agreement. If we are unable, for any reason beyond our reasonable control (including an unanticipated increase in demand beyond the production capacity of the manufacturing sites), to supply sufficient quantities of Feraheme, we agree to promptly establish an allocation procedure with respect to the available supply of Feraheme for the licensed territory and outside the licensed territory. Takeda may obtain Feraheme from a designated second source established by us if necessary to meet increased demand, or upon the occurrence of certain defined insolvency events. If we are unable to perform our supply obligations under the Supply Agreement after a negotiated period of time following an insolvency event, Takeda can seek permanent alternative supply sources and the parties’ supply and purchase obligations under the Supply Agreement will terminate. The Supply Agreement provides that it will otherwise remain in place for the duration of the Amended Takeda Agreement.
	In addition, the Supply Agreement provides pricing terms and provides that Takeda will reimburse us for certain capital expenditures and shall pay us a per-vial manufacturing fee. The Supply Agreement also specifies cost-sharing arrangements relating to future process changes or improvements to the manufacturing process for Feraheme. We generally agree to indemnify Takeda and its affiliates for damages resulting from the willful misconduct or gross negligence by us or a designated second source with respect to the manufacture of Feraheme, or resulting from our breach of the Supply Agreement. Takeda generally agrees to indemnify us, our affiliates and any designated second source for damages resulting with respect to the manufacture of Feraheme by Takeda or its affiliates, or resulting from Takeda’s breach of the Supply Agreement. The Supply Agreement includes quality control and testing terms, representations and warranties of the parties and other provisions customary for an agreement of this type.
	3SBio, Inc.
	In 2008, we entered into a Collaboration and Exclusive License Agreement with 3SBio Inc. (“3SBio”) for the development and commercialization of Feraheme as an IV iron replacement therapeutic agent in China. In consideration of the grant of the license, we received an upfront payment of $1.0 million. In January 2014, we mutually terminated the agreement with 3SBio, effective immediately, due to the fact that, despite the best efforts of the parties, regulatory approval in China could not be obtained within the agreed upon time period. During the nine months ended September 30, 2014, we recognized the $1.0 million upfront payment into revenue as we have no future continuing obligations and have included it in license fee and other collaboration revenues in our condensed consolidated statement of operations.
	PlasmaTech
	Please refer to Note H, “Business Combination,” for a detailed description of the MuGard License Agreement.

Debt

Debt	9 Months Ended
	Sep. 30, 2014
Debt	'
Debt	'
	P.Debt
	2.5% Convertible Notes
	On February 14, 2014, we issued $200.0 million aggregate principal amount of Convertible Notes, which includes $25.0 million principal amount of Convertible Notes issued pursuant to the full exercise of an over-allotment option granted to the underwriters in the offering. We received net proceeds of $193.3 million from the sale of the Convertible Notes, after deducting fees and expenses of $6.7 million. We used $14.1 million of the net proceeds from the sale of the Convertible Notes to pay the cost of the convertible bond hedges, as described below (after such cost was partially offset by the proceeds to us from the sale of warrants in the warrant transactions described below).
	The Convertible Notes are governed by the terms of an indenture between us, as issuer, and Wilmington Trust, National Association, as the Trustee. The Convertible Notes are senior unsecured obligations and bear interest at a rate of 2.5% per year, payable semi-annually in arrears on February 15 and August 15 of each year, beginning on August 15, 2014. The Convertible Notes will mature on February 15, 2019, unless earlier repurchased or converted. The Convertible Notes will be convertible into cash, shares of our common stock, or a combination thereof, at our election, at an initial conversion rate of approximately 36.9079 shares of common stock per $1,000 principal amount of the Convertible Notes, which corresponds to an initial conversion price of approximately $27.09 per share of our common stock and represents a conversion premium of approximately 35% based on the last reported sale price of our common stock of $20.07 on February 11, 2014, the date the notes offering was priced.
	The conversion rate is subject to adjustment from time to time upon the occurrence of certain events, including, but not limited to, the issuance of stock dividends and payment of cash dividends. At any time prior to the close of business on the business day immediately preceding May 15, 2018, holders may convert their Convertible Notes at their option only under the following circumstances:
	(1)during any calendar quarter commencing after the calendar quarter ended on March 31, 2014 (and only during such calendar quarter), if the last reported sale price of our common stock for at least 20 trading days (whether or not consecutive) during a period of 30 consecutive trading days ending on the last trading day of the immediately preceding calendar quarter is greater than or equal to 130% of the conversion price on each applicable trading day;
	(2)during the five business day period after any five consecutive trading day period (the “measurement period”) in which the trading price per $1,000 principal amount of the Convertible Notes for each trading day of the measurement period was less than 98% of the product of the last reported sale price of our common stock and the conversion rate on each such trading day; or
	(3)upon the occurrence of specified corporate events.
	On or after May 15, 2018 until the close of business on the second scheduled trading day immediately preceding the maturity date, holders may convert all or any portion of their Convertible Notes, in multiples of $1,000 principal amount, at the option of the holder regardless of the foregoing circumstances.
	If a make-whole fundamental change, as described in the indenture, occurs and a holder elects to convert its Convertible Notes in connection with such make-whole fundamental change, such holder may be entitled to an increase in the conversion rate as described in the indenture.
	We may not redeem the Convertible Notes prior to the maturity date and no “sinking fund” is provided for the Convertible Notes, which means that we are not required to periodically redeem or retire the Convertible Notes. Upon the occurrence of certain fundamental changes involving us, holders of the Convertible Notes may require us to repurchase for cash all or part of their Convertible Notes at a repurchase price equal to 100% of the principal amount of the Convertible Notes to be repurchased, plus accrued and unpaid interest.
	The indenture does not contain any financial or maintenance covenants or restrictions on the payments of dividends, the incurrence of indebtedness or the issuance or repurchase of securities by us or any of our subsidiaries. The indenture contains customary terms and covenants and events of default. If an event of default (other than certain events of bankruptcy, insolvency or reorganization involving us) occurs and is continuing, the Trustee by notice to us, or the holders of at least 25% in principal amount of the outstanding Convertible Notes by written notice to us and the Trustee, may declare 100% of the principal of and accrued and unpaid interest, if any, on all of the Convertible Notes to be due and payable. Upon such a declaration of acceleration, such principal and accrued and unpaid interest, if any, will be due and payable immediately. Upon the occurrence of certain events of bankruptcy, insolvency or reorganization involving us, 100% of the principal of and accrued and unpaid interest, if any, on all of the Convertible Notes will become due and payable automatically. Notwithstanding the foregoing, the indenture provides that, to the extent we elect and for up to 270 days, the sole remedy for an event of default relating to certain failures by us to comply with certain reporting covenants in the indenture consists exclusively of the right to receive additional interest on the Convertible Notes.
	In accordance with accounting guidance for debt with conversion and other options, we separately account for the liability and equity components of the Convertible Notes by allocating the proceeds between the liability component and the embedded conversion option (“equity component”) due to our ability to settle the Convertible Notes in cash, common stock or a combination of cash and common stock, at our option. The carrying amount of the liability component was calculated by measuring the fair value of a similar liability that does not have an associated convertible feature. The allocation was performed in a manner that reflected our non-convertible debt borrowing rate for similar debt. The equity component of the Convertible Notes was recognized as a debt discount and represents the difference between the proceeds from the issuance of the Convertible Notes and the fair value of the liability of the Convertible Notes on their respective dates of issuance. The excess of the principal amount of the liability component over its carrying amount (“debt discount”) is amortized to interest expense using the effective interest method over five years (the “life of the Convertible Notes”). The equity component is not remeasured as long as it continues to meet the conditions for equity classification.
	Our outstanding convertible note balances as September 30, 2014 consisted of the following (in thousands):
		September 30, 2014
	Liability component:
	Principal	$	200,000
	Less: debt discount, net	(34,222		)
	Net carrying amount	$	165,778
	Equity component	$	38,188
	In connection with the issuance of the Convertible Notes, we incurred approximately $6.7 million of debt issuance costs, which primarily consisted of underwriting, legal and other professional fees, and allocated these costs to the liability and equity components based on the allocation of the proceeds. Of the total $6.7 million of debt issuance costs, $1.3 million were allocated to the equity component and recorded as a reduction to additional paid-in capital and $5.4 million were allocated to the liability component and recorded as assets on the balance sheet. The portion allocated to the liability component is amortized to interest expense over the expected life of the Convertible Notes using the effective interest method.
	We determined the expected life of the debt was equal to the five year term on the Convertible Notes. As of September 30, 2014, the carrying value of the Convertible Notes was $165.8 million and the fair value of the Convertible Notes was $271.2 million. The effective interest rate on the liability component was 7.23% for the period from the date of issuance through September 30, 2014. The following table sets forth total interest expense recognized related to the Convertible Notes during the three and nine months ended September 30, 2014 (in thousands):
		Three Months Ended			Nine Months Ended
		September 30, 2014			September 30, 2014
	Contractual interest expense	$	1,250		$	3,125
	Amortization of debt issuance costs	234			564
	Amortization of debt discount	1,645			3,967
	Total interest expense	$	3,129		$	7,656
	Convertible Bond Hedge and Warrant Transactions
	In connection with the pricing of the Convertible Notes and in order to reduce the potential dilution to our common stock and/or offset cash payments due upon conversion of the Convertible Notes, on February 11, 2014 and February 13, 2014, we entered into convertible bond hedge transactions covering approximately 7.4 million shares of our common stock underlying the $200.0 million aggregate principal amount of the Convertible Notes, including the exercise of the over-allotment option, with JPMorgan Chase Bank, National Association, London Branch, Morgan Stanley & Co. International plc and Royal Bank of Canada (together the “Call Spread Counterparties”). The convertible bond hedges have an exercise price of approximately $27.09 per share, subject to adjustment upon certain events, and are exercisable when and if the Convertible Notes are converted. If upon conversion of the Convertible Notes, the price of our common stock is above the exercise price of the convertible bond hedges, the Call Spread Counterparties will deliver shares of our common stock and/or cash with an aggregate value approximately equal to the difference between the price of our common stock at the conversion date and the exercise price, multiplied by the number of shares of our common stock related to the convertible bond hedges being exercised. The convertible bond hedges are separate transactions entered into by us and are not part of the terms of the Convertible Notes or the warrants, discussed below. Holders of the Convertible Notes will not have any rights with respect to the convertible bond hedges. We paid $39.8 million for these convertible bond hedges and recorded this amount as a reduction to additional paid-in capital, net of tax, in the first quarter of 2014.
	At the same time, we also entered into separate warrant transactions with each of the Call Spread Counterparties relating to, in the aggregate, approximately 7.4 million shares of our common stock underlying the $200.0 million aggregate principal amount of the Convertible Notes, including the exercise of the over-allotment option. The initial exercise price of the warrants is $34.12 per share, subject to adjustment upon certain events, which is 70% above the last reported sale price of our common stock of $20.07 on February 11, 2014. The warrants would separately have a dilutive effect to the extent that the market value per share of our common stock, as measured under the terms of the warrants, exceeds the applicable exercise price of the warrants. The warrants were issued to the Call Spread Counterparties pursuant to the exemption from registration set forth in Section 4(a)(2) of the Securities Act of 1933, as amended. We received $25.7 million for these warrants and recorded this amount to additional paid-in capital in the first quarter of 2014.
	Aside from the initial payment of a $39.8 million premium to the Call Spread Counterparties under the convertible bond hedges, which amount is partially offset by the receipt of a $25.7 million premium under the warrants, we are not required to make any cash payments to the Call Spread Counterparties under the convertible bond hedges and will not receive any proceeds if the warrants are exercised.

Stockholders_Equity

Stockholders' Equity	9 Months Ended
	Sep. 30, 2014
Stockholders' Equity	'
Stockholders' Equity	'
	Q.Stockholders’ Equity
	In connection with the pricing of the Convertible Notes, on February 11, 2014, we and American Stock Transfer & Trust Company, LLC (the “Rights Agent”) entered into an amendment (the “Convertible Notes Amendment”) to our shareholder rights plan, dated as of September 4, 2009 (the “Rights Agreement”) between us and the Rights Agent. The Convertible Notes Amendment, among other things, provides that, notwithstanding anything in the Rights Agreement to the contrary, each Call Spread Counterparty shall be deemed not to beneficially own any common shares underlying, or synthetically owned pursuant to, any warrant held by such Call Spread Counterparty, any common shares held by such Call Spread Counterparty (or any affiliate thereof) to hedge its exposure with respect to the convertible bond hedges and warrants, any common shares underlying, or synthetically owned pursuant to, any Derivative Securities (as such term is defined in the Rights Agreement), including the Convertible Notes, held, or entered into, by such Call Spread Counterparty (or any affiliate thereof) to hedge its exposure with respect to the convertible bond hedges and warrants or any Convertible Notes held by such Call Spread Counterparty (or any affiliate thereof) in its capacity as underwriter in the notes offering.
	On September 26, 2014, we adopted the NOL Amendment to our Rights Agreement to help preserve our substantial tax assets associated with NOLs and other tax benefits by deterring certain stockholders from increasing their percentage ownership in our stock. The NOL Amendment shortens the expiration date of the Rights Agreement from September 17, 2019 to March 31, 2017, decreases the exercise price of the rights from $250.0 to $80.0 in connection therewith, and makes changes to the definition of “beneficial ownership,” as used in the Rights Agreement, as amended, to make it consistent with how ownership is defined under Section 382 of the Internal Revenue Code of 1986, as amended. The original Rights Agreement provided for a dividend distribution of one preferred share purchase right (a “Right”) for each outstanding share of our common stock, which dividend was paid on September 17, 2009. Rights will separate from the common stock and will become exercisable upon the earlier of (a) the close of business on the 10th calendar day following the first public announcement that a person or group of affiliated or associated persons has acquired beneficial ownership of 4.99% or more (which percentage had been 20% before the NOL Amendment) of the outstanding shares of common stock, other than as a result of repurchases of stock by us or certain inadvertent actions by a stockholder or (b) the close of business on the 10th business day (or such later day as the Board may determine) following the commencement of a tender offer or exchange offer that could result, upon its consummation, in a person or group becoming the beneficial owner of 4.99% or more (which percentage had been 20% before the NOL Amendment) of the outstanding shares of common stock (the earlier of such dates being herein referred to as the “Distribution Date”).
	The NOL Amendment provides that the Rights are not exercisable until the Distribution Date and will expire at the earliest of (a) March 31, 2017, (b) the time at which the Rights are redeemed or exchanged, (c) the effective date of the repeal of Section 382 or any successor statute if the Board determines that the NOL Rights Plan is no longer necessary or desirable for the preservation of our tax benefits, (d) the first day of our taxable year to which the Board determines that no tax benefits may be carried forward or (e) September 26, 2015 if stockholder approval of the NOL Amendment has not been obtained by or on such date.
	We expect to submit the NOL Amendment to a vote of our stockholders at our 2015 annual meeting of stockholders. There can be no assurance that the NOL Amendment will result in us being able to preserve all or any of the substantial tax assets associated with NOLs and other tax benefits.
	Total stockholders’ equity increased $24.6 million compared to December 31, 2013. This increase was primarily driven by $38.2 million allocated to the equity portion of our Convertible Notes, as described in Note P, “Debt,” $6.2 million in stock-based compensation expense and $2.9 million from the exercise of stock options. These increases were partially offset by our net loss of $7.2 million, $14.1 million paid for the cost of the convertible bond hedges, net of the sale of warrants, and $1.3 million in debt issuance costs that were allocated to the equity component of the Convertible Notes, also described further in Note P “Debt.”

Recently_Issued_and_Proposed_A

Recently Issued and Proposed Accounting Pronouncements	9 Months Ended
	Sep. 30, 2014
Recently Issued and Proposed Accounting Pronouncements	'
Recently Issued and Proposed Accounting Pronouncements	'
	R.Recently Issued and Proposed Accounting Pronouncements
	In May 2014, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2014-09, Revenue from Contracts with Customers, as a new Topic, Accounting Standards Codification Topic 606. The new revenue recognition standard provides a five-step analysis of transactions to determine when and how revenue is recognized. The core principle is that a company should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. This ASU is effective for us on January 1, 2017 and shall be applied retrospectively to each period presented or as a cumulative-effect adjustment as of the date of adoption. We are in the process of evaluating the effect of adopting this new accounting guidance and are uncertain at this point of the impact on our results of operations, cash flows or financial position.
	In August 2014, the FASB issued ASU No. 2014-15, Presentation of Financial Statements - Going Concern: Disclosure of Uncertainties about an Entity’s Ability to Continue as a Going Concern. ASU No. 2014-15 is intended to define management’s responsibility to evaluate whether there is substantial doubt about an organization’s ability to continue as a going concern and to provide related footnote disclosures, if required. ASU 2014-15 will be effective for annual reporting periods ending after December 15, 2016, which will be our fiscal year ending December 31, 2016, and to annual and interim periods thereafter. We are in the process of evaluating the impact of adoption of ASU 2014-15 on our condensed consolidated financial statements and related disclosures and currently do not expect it to have a material impact our results of operations, cash flows or financial position.
	From time to time, new accounting pronouncements are issued by FASB or other standard setting bodies that are adopted by us as of the specified effective date. Unless otherwise discussed, we believe that the impact of recently issued standards that are not yet effective will not have a material impact on our financial position or results of operations upon adoption.

Subsequent_Event

Subsequent Event	9 Months Ended
	Sep. 30, 2014
Subsequent Event	'
Subsequent Event	'
	S.Subsequent Event
	Lumara Agreement
	On September 28, 2014, we entered into an Agreement and Plan of Merger (the “Lumara Agreement”) with inter alia, Lumara. The Lumara Agreement provides that, at the effective time of the merger, upon the terms and subject to the conditions set forth in the Lumara Agreement, a wholly-owned merger subsidiary of AMAG will merge with and into Lumara, with Lumara continuing as the surviving entity and our wholly-owned subsidiary. Lumara is a privately held pharmaceutical company specializing in women’s health which markets Makena® (hydroxyprogesterone caproate injection), a progestin indicated to reduce the risk of preterm birth in women with a singleton pregnancy who have a history of singleton spontaneous preterm birth.
	Subject to the terms and conditions of the Lumara Agreement, we have agreed to pay an aggregate of $675.0 million in upfront merger consideration consisting of a combination of $600.0 million in cash (the “Cash Consideration”) and 3,209,971 unregistered shares of our common stock.
	The Lumara Agreement includes future contingent payments of up to $350.0 million in cash (or upon mutual agreement between us and the Lumara security holders, future contingent payments may also be made in stock or some combination thereof) payable by us to the Lumara security holders based upon the achievement of certain sales milestones through calendar year 2019.
	The Lumara Agreement contains customary representations, warranties and covenants of the parties as well as customary conditions to closing, including among other things, the representations and warranties of Lumara being true and correct at the closing subject to the terms of the Lumara Agreement and the absence of any material adverse changes affecting Lumara. In addition, the Lumara Agreement provides for limited termination rights, including but not limited to, by the mutual consent of us and the stockholders’ representative; upon certain breaches of representations, warranties, covenants or agreements; and in the event the merger has not been consummated before January 31, 2015. We expect to consummate the merger in the fourth quarter of 2014. We will not incur any termination fees in the event the merger is not consummated.
	Commitment Letter
	Pursuant to the Lumara Agreement, we are obligated to obtain financing to fund a portion of the Cash Consideration. Receipt of financing by us is not a condition to our obligations under the Lumara Agreement.
	Concurrently with the execution and delivery of the Lumara Agreement, Jefferies Finance LLC (“Jefferies”) entered into a commitment letter with us (the “Commitment Letter”), pursuant to which Jefferies and other lenders have committed to provide a senior secured term loan facility to us of up to $340.0 million (the “Term Loan Facility”) subject to customary conditions set forth in the Commitment Letter. We expect to enter into the Term Loan Facility and to use the proceeds of the Term Loan Facility, together with cash on hand and other available sources of funding, to (a) pay a portion of the Cash Consideration and (b) pay various fees and expenses incurred in connection with the Lumara merger and the Term Loan Facility.
	The obligations of the Lenders to provide the financing under the Commitment Letter for the Term Loan Facility are subject to customary conditions for acquisition financings, including conditions that do not relate directly to the Lumara Agreement, such as the tolling of a 15-business-day marketing period (with customary exclusions for holidays) for Jefferies to syndicate the Term Loan Facility. The Commitment Letter expires on the earliest of (a) the date that is five business days after the valid termination of the Lumara Agreement, (b) the closing of the Lumara merger (unless the lenders have failed to fund in breach of their obligations under the Commitment Letter) and (c) January 30, 2015. The Term Loan Facility amortizes in quarterly installments over the term of the Term Loan Facility, is secured by substantially all of our assets and the assets of our subsidiaries and is guaranteed by certain of our subsidiaries.
	Pursuant to the Commitment Letter and in accordance with the terms of a fee letter entered into between Jefferies and us, Jefferies and the lenders expect to receive certain customary fees, some of which are based on their pro rata participation under the Commitment Letter, from us, including certain fees payable depending on various circumstances and contingencies. In addition, the fee letter includes certain “market-flex” provisions. The Term Loan Facility contemplated by the Commitment Letter will impose restrictive covenants on us, including a requirement that we reduce our leverage over time, and obligate us to make certain payments of principal and interest over time.

Basis_of_Presentation_and_Summ1

Basis of Presentation and Summary of Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2014
Basis of Presentation and Summary of Significant Accounting Policies	'
Use of Estimates and Assumptions	'
	Use of Estimates and Assumptions
	The preparation of condensed consolidated financial statements in conformity with GAAP requires management to make certain estimates and assumptions that affect the reported amounts of assets, liabilities, revenues and expenses, and the related disclosure of contingent assets and liabilities. The most significant estimates and assumptions are used in, but are not limited to, revenue recognition related to product sales and collaboration agreements, product sales allowances and accruals, assessing investments for potential other-than-temporary impairment, determining the fair values of our investments, assets acquired in a business combination, debt obligations, and contingent consideration, the impairment of long-lived assets, including intangible assets, accrued expenses, and equity-based compensation expense. Actual results could differ materially from those estimates.
Cash and Cash Equivalents	'
	Cash and Cash Equivalents
	Cash and cash equivalents consists principally of cash held in commercial bank accounts, money market funds and U.S. Treasury securities having an original maturity of less than three months. We consider all highly liquid investments with a maturity of three months or less as of the acquisition date to be cash equivalents. At September 30, 2014, substantially all of our cash and cash equivalents were held in either commercial bank accounts or money market funds.
Principles of Consolidation	'
	Principles of Consolidation
	The accompanying condensed consolidated financial statements include our accounts and the accounts of our wholly-owned subsidiaries. All intercompany account balances and transactions between the companies have been eliminated.
Fair Value Measurements	'
	Fair Value Measurements
	Under current accounting standards, fair value is defined as the exchange price that would be received for an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. Valuation techniques used to measure fair value must maximize the use of observable inputs and minimize the use of unobservable inputs.
	Current accounting guidance establishes a hierarchy used to categorize how fair value is measured and which is based on three levels of inputs, of which the first two are considered observable and the third unobservable, as follows:
	Level 1 - Quoted prices in active markets for identical assets or liabilities.
	Level 2 - Inputs other than Level 1 that are observable, either directly or indirectly, such as quoted prices for similar assets or liabilities, quoted prices in markets that are not active, or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities.
	Level 3 - Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities.
	We hold certain assets and liabilities that are required to be measured at fair value on a recurring basis, including our cash equivalents, investments, and contingent consideration.
Revenue Recognition and Related Sales Allowances and Accruals	'
	Revenue Recognition and Related Sales Allowances and Accruals
	We recognize revenue from the sale of our products as well as license fee and other collaboration revenues, including milestone payments, other product sale revenues, and royalties we receive from our licensees. We recognize revenue in accordance with current accounting guidance related to the recognition, presentation and disclosure of revenue in financial statements, which outlines the basic criteria that must be met to recognize revenue and provides guidance for disclosure of revenue in financial statements. We recognize revenue when:
	Persuasive evidence of an arrangement exists;
	Delivery of product has occurred or services have been rendered;
	The sales price charged is fixed or determinable; and
	Collection is reasonably assured.
	U.S. Feraheme Product Sales, Net
	An analysis of our U.S. Feraheme product sales allowances and accruals for the three and nine months ended September 30, 2014 and 2013 is as follows (in thousands):
		Three Months Ended September 30,
		2014			2013
	Provision for U.S. Feraheme product sales allowances and accruals
	Discounts and chargebacks	$	13,876		$	10,205
	Government and other rebates	4,161			3,044
	Medicaid rebate reserve adjustment	—			(625		)
	Returns	212			265
	Total provision for U.S. Feraheme product sales allowances and accruals	18,249			12,889
	Total gross U.S. Feraheme product sales	$	40,796		$	32,236
	Total provision for U.S. Feraheme product sales allowances and accruals as a percent of total gross U.S. Feraheme product sales	45		%	40		%
		Nine Months Ended September 30,
		2014			2013
	Provision for U.S. Feraheme product sales allowances and accruals
	Discounts and chargebacks	$	37,824		$	26,925
	Government and other rebates	11,300			8,106
	Medicaid rebate reserve adjustment	—			(568		)
	Returns	584			697
	Total provision for U.S. Feraheme product sales allowances and accruals	49,708			35,160
	Total gross U.S. Feraheme product sales	$	111,855		$	87,541
	Total provision for U.S. Feraheme product sales allowances and accruals as a percent of total gross U.S. Feraheme product sales	44		%	40		%
	Consistent with industry practice, we generally offer our wholesalers, specialty distributors and other customers a limited right to return Feraheme based on the product’s expiration date which, once packaged, is currently five years in the U.S. We estimate product returns based on the historical return patterns and known or expected changes in the marketplace. We track actual returns by individual production lots. Returns on lots eligible for credits under our returned goods policy are monitored and compared with historical return trends and rates.
	We expect that wholesalers and healthcare providers will not stock significant inventory due to the cost and expense to store Feraheme. We record an estimate of returns at the time of sale. If necessary, our estimated rate of returns may be adjusted for actual return experience as it becomes available and for known or expected changes in the marketplace. During the nine months ended September 30, 2014, we reduced our reserve for product returns by $0.3 million due to the lapse of the product return period on certain manufactured Feraheme lots. We did not significantly adjust our reserve for product returns during the nine months ended September 30, 2013. To date, returns of Feraheme have been relatively limited; however returns experience may change over time. As we continue to gain more historical experience with actual returns, we may be required to make a future adjustment to our product returns estimate, which would result in a corresponding change to our net product sales in the period of adjustment and could be significant.
	In addition, as part of our sales allowances and accruals, we reserve for estimated Medicaid rebates associated with instances where Medicaid will act as the insurer and for which we are required to pay a statutory rebate to Medicaid. We regularly assess our Medicaid reserve balance and the rate at which we accrue for claims against product sales. We did not adjust our Medicaid reserve balance during the nine months ended September 30, 2014. During the nine months ended September 30, 2013, we revised our estimated Medicaid reserve rate based on actual product-specific rebate claims received since the July 2009 launch of Feraheme, our expectations of state level activities, and estimated rebate claims not yet submitted, which resulted in a $0.6 million reduction of our then estimated Medicaid rebate reserve related to prior period Feraheme sales. This change in estimate was reflected as an increase in our net product sales for the nine months ended September 30, 2013 and resulted in reductions to our gross to net percentage in that period. The reduction of our estimated Medicaid rebate reserve had an impact of $0.03 per basic and diluted share for the nine months ended September 30, 2013. If we determine in future periods that our actual rebate experience is not indicative of expected claims, if our actual claims experience changes, or if other factors affect estimated claims rates, we may be required to adjust our current Medicaid accumulated reserve estimate, which would affect our net product sales in the period of the adjustment and could be significant.

Basis_of_Presentation_and_Summ2

Basis of Presentation and Summary of Significant Accounting Policies (Tables)	9 Months Ended
	Sep. 30, 2014
Basis of Presentation and Summary of Significant Accounting Policies	'
Analysis of U.S. Feraheme product sales allowances and accruals	'
	An analysis of our U.S. Feraheme product sales allowances and accruals for the three and nine months ended September 30, 2014 and 2013 is as follows (in thousands):
		Three Months Ended September 30,
		2014			2013
	Provision for U.S. Feraheme product sales allowances and accruals
	Discounts and chargebacks	$	13,876		$	10,205
	Government and other rebates	4,161			3,044
	Medicaid rebate reserve adjustment	—			(625		)
	Returns	212			265
	Total provision for U.S. Feraheme product sales allowances and accruals	18,249			12,889
	Total gross U.S. Feraheme product sales	$	40,796		$	32,236
	Total provision for U.S. Feraheme product sales allowances and accruals as a percent of total gross U.S. Feraheme product sales	45		%	40		%
		Nine Months Ended September 30,
		2014			2013
	Provision for U.S. Feraheme product sales allowances and accruals
	Discounts and chargebacks	$	37,824		$	26,925
	Government and other rebates	11,300			8,106
	Medicaid rebate reserve adjustment	—			(568		)
	Returns	584			697
	Total provision for U.S. Feraheme product sales allowances and accruals	49,708			35,160
	Total gross U.S. Feraheme product sales	$	111,855		$	87,541
	Total provision for U.S. Feraheme product sales allowances and accruals as a percent of total gross U.S. Feraheme product sales	44		%	40		%
Schedule of customers representing 10% or more of revenues	'
		Nine Months Ended September 30,
		2014		2013
	AmerisourceBergen Drug Corporation	39	%	43	%
	McKesson Corporation	24	%	23	%
	Cardinal Health, Inc.	18	%	16	%
	Takeda Pharmaceuticals Company Limited	10	%	11	%

Investments_Tables

Investments (Tables)	9 Months Ended
	Sep. 30, 2014
Investments	'
Summary of investments	'
	The following is a summary of our investments as of September 30, 2014 and December 31, 2013 (in thousands):
		September 30, 2014
				Gross		Gross			Estimated
		Amortized		Unrealized		Unrealized			Fair
		Cost		Gains		Losses			Value
	Corporate debt securities
	Due in one year or less	$	47,057	$	56	$	(5	)	$	47,108
	Due in one to three years	87,529		100		(147		)	87,482
	U.S. treasury and government agency securities
	Due in one year or less	22,978		27		—			23,005
	Due in one to three years	30,986		32		(25		)	30,993
	Commercial paper
	Due in one year or less	1,500		—		—			1,500
	Total investments	$	190,050	$	215	$	(177	)	$	190,088
		December 31, 2013
				Gross		Gross			Estimated
		Amortized		Unrealized		Unrealized			Fair
		Cost		Gains		Losses			Value
	Corporate debt securities
	Due in one year or less	$	42,609	$	44	$	(4	)	$	42,649
	Due in one to three years	91,443		137		(106		)	91,474
	U.S. treasury and government agency securities
	Due in one year or less	18,526		19		—			18,545
	Due in one to three years	34,123		37		(25		)	34,135
	Total investments	$	186,701	$	237	$	(135	)	$	186,803

Fair_Value_Measurements_Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2014
Fair Value Measurements	'
Schedule of assets and liabilities measured at fair value on a recurring basis	'
	The following tables represent the fair value hierarchy as of September 30, 2014 and December 31, 2013 for those assets and liabilities that we measure at fair value on a recurring basis (in thousands):
		Fair Value Measurements at September 30, 2014 Using:
					Quoted Prices in Active		Significant Other		Significant
					Markets for Identical		Observable Inputs		Unobservable
					Assets				Inputs
		Total			(Level 1)		(Level 2)		(Level 3)
	Assets:
	Money market funds	$	191,258		$	191,258	$	—	$	—
	Corporate debt securities	134,590			—		134,590		—
	U.S. treasury and government agency securities	53,998			—		53,998		—
	Commercial paper	1,500			—		1,500		—
	Total Assets	$	381,346		$	191,258	$	190,088	$	—
	Liabilities:
	Acquisition-related contingent consideration	$	11,848		—		—		11,848
	Total Liabilities	$	11,848		$	—	$	—	$	11,848
		Fair Value Measurements at December 31, 2013 Using:
					Quoted Prices in Active		Significant Other		Significant
					Markets for Identical		Observable Inputs		Unobservable
					Assets				Inputs
		Total			(Level 1)		(Level 2)		(Level 3)
	Assets:
	Money market funds	$	18,767		$	18,767	$	—	$	—
	Corporate debt securities	134,123			—		134,123		—
	U.S. treasury and government agency securities	52,680			—		52,680		—
	Total Assets	$	205,570		$	18,767	$	186,803	$	—
	Liabilities:
	Acquisition-related contingent consideration	$	14,550		$	—	$	—	$	14,550
	Total Liabilities	$	14,550		$	—	$	—	$	14,550
Schedule of reconciliation of contingent consideration obligations related to acquisition of MuGard rights measured on recurring basis using Level 3 inputs	'
	The following table presents a reconciliation of contingent consideration obligations related to our acquisition of the MuGard Rights measured on a recurring basis using Level 3 inputs as of September 30, 2014 (in thousands):
	Balance as of December 31, 2013	$	14,550
	Payments made	(186		)
	Adjustments to fair value of contingent consideration	(2,535		)
	Other adjustments	19
	Balance as of September 30, 2014	$	11,848

Accounts_Receivable_Net_Tables

Accounts Receivable, Net (Tables)	9 Months Ended
	Sep. 30, 2014
Accounts Receivable, Net	'
Schedule of customers representing greater than 10% of accounts receivable balances	'
		September 30, 2014		December 31, 2013
	AmerisourceBergen Drug Corporation	51	%	43	%
	McKesson Corporation	26	%	29	%
	Cardinal Health, Inc.	15	%	19	%

Inventories_Tables

Inventories (Tables)	9 Months Ended
	Sep. 30, 2014
Inventories	'
Schedule of major classes of inventories	'
	Our major classes of inventories were as follows as of September 30, 2014 and December 31, 2013 (in thousands):
		September 30, 2014		December 31, 2013
	Raw materials	$	4,341	$	3,157
	Work in process	7,158		8,322
	Finished goods	8,081		5,738
	Total inventories	$	19,580	$	17,217

Property_and_Equipment_Net_Tab

Property and Equipment, Net (Tables)	9 Months Ended
	Sep. 30, 2014
Property and Equipment, Net	'
Schedule of property and equipment	'
	Property and equipment consisted of the following as of September 30, 2014 and December 31, 2013 (in thousands):
		September 30, 2014			December 31, 2013
	Furniture and fixtures	$	1,509		$	1,536
	Leasehold improvements	430			430
	Laboratory and production equipment	492			376
		2,431			2,342
	Less - accumulated depreciation	(849		)	(496		)
	Property and equipment, net	$	1,582		$	1,846

Business_Combination_Tables

Business Combination (Tables)	9 Months Ended
	Sep. 30, 2014
Business Combination	'
Summary of total consideration for the MuGard Rights	'
	The following table summarizes the total consideration for the MuGard Rights (in thousands):
	Consideration:
	Cash	$	3,434
	Acquisition-related contingent consideration	13,700
	Total consideration	$	17,134
Summary of estimated fair values of the assets acquired related to the business combination	'
	The following table summarizes the estimated fair values of the assets acquired related to the business combination as of the Acquisition Date (in thousands):
	Assets Acquired:
	MuGard intangible asset	$	16,893
	Inventory	241
	Net identifiable assets acquired	$	17,134

Accumulated_Other_Comprehensiv1

Accumulated Other Comprehensive Loss (Tables)	9 Months Ended
	Sep. 30, 2014
Accumulated Other Comprehensive Loss	'
Schedule of changes in accumulated other comprehensive loss, net of tax	'
	The changes in accumulated other comprehensive loss, net of tax, for the three and nine months ended September 30, 2014 and 2013 consisted of the following (in thousands):
		Three Months Ended September 30,						Nine Months Ended September 30,
		2014			2013			2014			2013
	Beginning Balance	$	(3,259	)	$	(3,935	)	$	(3,491	)	$	(3,247	)
	Other comprehensive income (loss) before reclassifications	(305		)	399			(76		)	(310		)
	Gain reclassified from other accumulated comprehensive loss	9			—			12			21
	Ending Balance	$	(3,555	)	$	(3,536	)	$	(3,555	)	$	(3,536	)

Basic_and_Diluted_Net_Income_L1

Basic and Diluted Net Income (Loss) per Share (Tables)	9 Months Ended
	Sep. 30, 2014
Basic and Diluted Net Income (Loss) per Share	'
Schedule of components of basic and diluted net income (loss) per share	'
	The components of basic and diluted net income (loss) per share for the three and nine months ended September 30, 2014 and 2013 were as follows (in thousands, except per share data):
		Three Months Ended September 30,						Nine Months Ended September 30,
		2014			2013			2014			2013
	Net income (loss)	$	1,458		$	(145	)	$	(7,191	)	$	(5,948	)
	Weighted average common shares outstanding	21,984			21,691			21,912			21,613
	Effect of dilutive securities:
	Stock options and restricted stock units	369			—			—			—
	Convertible 2.5% senior notes	1,114			—			—			—
	Shares used in calculating dilutive net income (loss) per share	23,467			21,691			21,912			21,613
	Net income (loss) per share:
	Basic	$	0.07		$	(0.01	)	$	(0.33	)	$	(0.28	)
	Diluted	$	0.06		$	(0.01	)	$	(0.33	)	$	(0.28	)
Schedule of anti-dilutive securities from computation of diluted net Income (loss) per share	'
		Three Months Ended September 30,				Nine Months Ended September 30,
		2014		2013		2014		2013
	Options to purchase shares of common stock	2,013		2,717		3,081		2,717
	Shares of common stock issuable upon the vesting of restricted stock units	289		497		760		497
	Warrants	7,382		—		7,382		—
	Total	9,684		3,214		11,223		3,214

EquityBased_Compensation_Table

Equity-Based Compensation (Tables)	9 Months Ended
	Sep. 30, 2014
Equity-Based Compensation	'
Schedule of equity-based compensation expense	'
	Equity-based compensation expense for the three and nine months ended September 30, 2014 and 2013 consisted of the following (in thousands):
		Three Months Ended September 30,				Nine Months Ended September 30,
		2014		2013		2014		2013
	Cost of product sales	$	32	$	25	$	89	$	83
	Research and development	466		337		1,274		1,634
	Selling, general and administrative	1,448		1,303		4,790		4,169
	Total equity-based compensation expense	$	1,946	$	1,665	$	6,153	$	5,886

Debt_Tables

Debt (Tables)	9 Months Ended
	Sep. 30, 2014
Debt	'
Schedule of outstanding convertible note balances	'
	Our outstanding convertible note balances as September 30, 2014 consisted of the following (in thousands):
		September 30, 2014
	Liability component:
	Principal	$	200,000
	Less: debt discount, net	(34,222		)
	Net carrying amount	$	165,778
	Equity component	$	38,188
Schedule of total interest expense recognized related to the Convertible Notes	'
	The following table sets forth total interest expense recognized related to the Convertible Notes during the three and nine months ended September 30, 2014 (in thousands):
		Three Months Ended			Nine Months Ended
		September 30, 2014			September 30, 2014
	Contractual interest expense	$	1,250		$	3,125
	Amortization of debt issuance costs	234			564
	Amortization of debt discount	1,645			3,967
	Total interest expense	$	3,129		$	7,656

Description_of_Business_Detail

Description of Business (Details) (Lumara Health Inc Member, USD $)	0 Months Ended			9 Months Ended	0 Months Ended
	Sep. 28, 2014	Sep. 28, 2014	Sep. 30, 2014	Sep. 30, 2014	Sep. 28, 2014	Sep. 28, 2014
			Commitment Letter Member	Commitment Letter Member	Subsequent Event [Member]	Subsequent Event [Member]
				Merger Agreement Terminated
Subsequent event	'	'	'	'	'	'
Upfront merger consideration	$675,000,000	'	'	'	$675,000,000	'
Amount in cash	600,000,000	'	'	'	600,000,000	'
Value in common stocks to pay	75,000,000	'	'	'	'	'
Number of common stock used to pay (in shares)	'	'	'	'	3,209,971	'
Maximum contingent consideration	'	350,000,000	'	'	'	350,000,000
Maximum borrowing capacity	'	'	$340,000,000	'	'	'
Maximum number of days for the commitment letter to expire	'	'	'	'5 days	'	'

Basis_of_Presentation_and_Summ3

Basis of Presentation and Summary of Significant Accounting Policies (Details ) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Provision for U.S. Feraheme product sales allowances and accruals	'	'	'	'
Discounts and chargebacks	$13,876,000	$10,205,000	$37,824,000	$26,925,000
Government and other rebates	4,161,000	3,044,000	11,300,000	8,106,000
Medicaid rebate reserve adjustment	'	-625,000	'	-568,000
Returns	212,000	265,000	584,000	697,000
Total provision for U.S. Feraheme product sales allowances and accruals	18,249,000	12,889,000	49,708,000	35,160,000
Total gross U.S. Feraheme product sales	40,796,000	32,236,000	111,855,000	87,541,000
Total provision for U.S. Feraheme product sales allowances and accruals as a percent of total gross U.S. Feraheme product sales	45.00%	40.00%	44.00%	40.00%
Current expiration for Feraheme	'	'	'5 years	'
Impact of Medicaid rebate reserve adjustment to basic and diluted earnings per share	'	'	'	$0.03
Product Returns	'	'	'	'
Reduction of reserve for product returns	'	'	$300,000	'

Basis_of_Presentation_and_Summ4

Basis of Presentation and Summary of Significant Accounting Policies (Details 2) (USD $)

Sep. 30, 2014

Dec. 31, 2013

Sep. 30, 2013

Dec. 31, 2012

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2014

Sep. 30, 2013

Sales Revenue, Net [Member]

Sales Revenue, Net [Member]

Sales Revenue, Net [Member]

Sales Revenue, Net [Member]

Sales Revenue, Net [Member]

Sales Revenue, Net [Member]

Sales Revenue, Net [Member]

Sales Revenue, Net [Member]

Sales Revenue, Net [Member]

Sales Revenue, Net [Member]

Sales Revenue, Net [Member]

Sales Revenue, Net [Member]

Customer Concentration Risk [Member]

Customer Concentration Risk [Member]

Customer Concentration Risk [Member]

Customer Concentration Risk [Member]

Customer Concentration Risk [Member]

Customer Concentration Risk [Member]

Customer Concentration Risk [Member]

Customer Concentration Risk [Member]

Customer Concentration Risk [Member]

Customer Concentration Risk [Member]

Geographic Concentration Risk [Member]

Geographic Concentration Risk [Member]

Amerisource Bergen Drug Corporation [Member]

Amerisource Bergen Drug Corporation [Member]

McKesson Corporation [Member]

McKesson Corporation [Member]

Cardinal Health Inc [Member]

Cardinal Health Inc [Member]

Takeda Pharmaceutical Company Limited [Member]

Takeda Pharmaceutical Company Limited [Member]

Group Purchasing Organization [Member]

Group Purchasing Organization [Member]

Investment Concentration Risk

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Cash, cash equivalents and investments

$386,200,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Investment in institutional money market funds

191,300,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Cash and cash equivalents

196,154,000

26,986,000

30,946,000

46,293,000

'

'

'

'

'

'

'

'

'

'

'

'

Amount invested in a single fund

$179,900,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Customers representing 10% or more of revenues

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Percentage of revenues from major customer

'

'

'

'

39.00%

43.00%

24.00%

23.00%

18.00%

16.00%

10.00%

11.00%

27.00%

32.00%

'

'

Percentage of revenues From customers outside of the U.S.

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Approximate percentage of revenues from customers outside the U.S.

'

'

'

'

'

'

'

'

'

'

'

'

'

'

11.00%

11.00%

Investments_Details

Investments (Details) (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Summary of Investments	'	'
Available-for-sale securities, Amortized Cost	$190,050	$186,701
Available-for-sale securities, Gross Unrealized Gains	215	237
Available-for-sale securities, Gross Unrealized Losses	-177	-135
Available-for-sale securities, Estimated Fair Value	190,088	186,803
Corporate Debt Securities [Member]	'	'
Summary of Investments	'	'
Available-for-sale securities due in one year or less, Amortized Cost	47,057	42,609
Available-for-sale securities due in one to three years, Amortized Cost	87,529	91,443
Available-for-sale securities due in one year or less, Gross Unrealized Gains	56	44
Available-for-sale securities due in one to three years, Gross Unrealized Gains	100	137
Available-for-sale securities due in one year or less, Gross Unrealized Losses	-5	-4
Available-for-sale securities due in one to three years, Gross Unrealized Losses	-147	-106
Available-for-sale securities due in one year or less, Estimated Fair Value	47,108	42,649
Available-for-sale securities due in one to three years, Estimated Fair Value	87,482	91,474
US Treasury and Government [Member]	'	'
Summary of Investments	'	'
Available-for-sale securities due in one year or less, Amortized Cost	22,978	18,526
Available-for-sale securities due in one to three years, Amortized Cost	30,986	34,123
Available-for-sale securities due in one year or less, Gross Unrealized Gains	27	19
Available-for-sale securities due in one to three years, Gross Unrealized Gains	32	37
Available-for-sale securities due in one to three years, Gross Unrealized Losses	-25	-25
Available-for-sale securities due in one year or less, Estimated Fair Value	23,005	18,545
Available-for-sale securities due in one to three years, Estimated Fair Value	30,993	34,135
Commercial Paper, Not Included with Cash and Cash Equivalents [Member]	'	'
Summary of Investments	'	'
Available-for-sale securities due in one year or less, Amortized Cost	1,500	'
Available-for-sale securities due in one year or less, Estimated Fair Value	$1,500	'

Fair_Value_Measurements_Detail

Fair Value Measurements (Details) (Fair Value, Measurements, Recurring [Member], USD $)	Sep. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Fair value of assets and liabilities measured on a recurring basis	'	'
Transfers or reclassifications of securities from Level 1 to Level 2	$0	'
Transfers or reclassifications of securities from Level 2 to Level 1	0	'
Estimate of Fair Value Measurement [Member]	'	'
Fair value of assets and liabilities measured on a recurring basis	'	'
Total Assets	381,346	205,570
Total Liabilities	11,848	14,550
Estimate of Fair Value Measurement [Member] | Acquisition Related Contingent Consideration [Member]	'	'
Fair value of assets and liabilities measured on a recurring basis	'	'
Total Liabilities	11,848	14,550
Estimate of Fair Value Measurement [Member] | Money Market Funds [Member]	'	'
Fair value of assets and liabilities measured on a recurring basis	'	'
Total Assets	191,258	18,767
Estimate of Fair Value Measurement [Member] | Corporate Debt Securities [Member]	'	'
Fair value of assets and liabilities measured on a recurring basis	'	'
Total Assets	134,590	134,123
Estimate of Fair Value Measurement [Member] | US Treasury and Government [Member]	'	'
Fair value of assets and liabilities measured on a recurring basis	'	'
Total Assets	53,998	52,680
Estimate of Fair Value Measurement [Member] | Commercial Paper, Not Included with Cash and Cash Equivalents [Member]	'	'
Fair value of assets and liabilities measured on a recurring basis	'	'
Total Assets	1,500	'
Fair Value, Inputs, Level 1 [Member]	'	'
Fair value of assets and liabilities measured on a recurring basis	'	'
Total Assets	191,258	18,767
Fair Value, Inputs, Level 1 [Member] | Money Market Funds [Member]	'	'
Fair value of assets and liabilities measured on a recurring basis	'	'
Total Assets	191,258	18,767
Fair Value, Inputs, Level 2 [Member]	'	'
Fair value of assets and liabilities measured on a recurring basis	'	'
Total Assets	190,088	186,803
Fair Value, Inputs, Level 2 [Member] | Corporate Debt Securities [Member]	'	'
Fair value of assets and liabilities measured on a recurring basis	'	'
Total Assets	134,590	134,123
Fair Value, Inputs, Level 2 [Member] | US Treasury and Government [Member]	'	'
Fair value of assets and liabilities measured on a recurring basis	'	'
Total Assets	53,998	52,680
Fair Value, Inputs, Level 2 [Member] | Commercial Paper, Not Included with Cash and Cash Equivalents [Member]	'	'
Fair value of assets and liabilities measured on a recurring basis	'	'
Total Assets	1,500	'
Fair Value, Inputs, Level 3 [Member]	'	'
Fair value of assets and liabilities measured on a recurring basis	'	'
Total Liabilities	11,848	14,550
Fair Value, Inputs, Level 3 [Member] | Acquisition Related Contingent Consideration [Member]	'	'
Fair value of assets and liabilities measured on a recurring basis	'	'
Total Liabilities	$11,848	$14,550

Fair_Value_Measurements_Detail1

Fair Value Measurements (Details 2) (USD $)

3 Months Ended

9 Months Ended

3 Months Ended

9 Months Ended

3 Months Ended

9 Months Ended

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2014

Feb. 14, 2014

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

Convertible Debt [Member]

Convertible Debt [Member]

Fair Value, Inputs, Level 2 [Member]

PlasmaTech Biopharmaceuticals Inc Member

PlasmaTech Biopharmaceuticals Inc Member

PlasmaTech Biopharmaceuticals Inc Member

PlasmaTech Biopharmaceuticals Inc Member

PlasmaTech Biopharmaceuticals Inc Member

PlasmaTech Biopharmaceuticals Inc Member

PlasmaTech Biopharmaceuticals Inc Member

Convertible Debt [Member]

Licensing Agreements [Member]

Licensing Agreements [Member]

Licensing Agreements [Member]

Licensing Agreements [Member]

Licensing Agreements [Member]

Fair Value, Inputs, Level 3 [Member]

Minimum [Member]

Maximum [Member]

Reconciliation of contingent consideration obligations related to acquisition of MuGard rights

'

'

'

'

'

'

'

'

'

'

'

'

'

Balance at beginning of period

'

'

'

'

'

'

'

'

'

$14,550,000

'

'

'

Payments made

'

'

'

'

'

'

'

'

'

-186,000

'

'

'

Adjustments to fair value of contingent consideration

'

-2,535,000

279,000

'

'

'

-3,700,000

-2,500,000

-3,700,000

-2,535,000

'

'

'

Impact of the adjustment on contingent consideration liability to earning per share basic and diluted (USD per share)

'

$0.12

'

'

'

'

'

'

'

'

'

'

'

Impact of the adjustment on contingent consideration liability to earning per share basic (USD per share)

$0.17

'

'

'

'

'

'

'

'

'

'

'

'

Impact of the adjustment on contingent consideration liability to earning per share diluted (USD per share)

$0.16

'

'

'

'

'

'

'

'

'

'

'

'

Other adjustments

'

'

'

'

'

'

'

'

'

19,000

'

'

'

Balance at end of period

'

'

'

'

'

'

'

'

11,848,000

11,848,000

'

'

'

Estimated undiscounted royalty amounts payable

'

'

'

'

'

'

'

'

'

'

'

20,000,000

28,000,000

Period over which estimated undiscounted royalty amounts could be paid

'

'

'

'

'

'

'

'

'

'10 years

'

'

'

Discount rate (as a percent)

'

'

'

'

'

'

'

'

'

'

15.00%

'

'

Contingent consideration classified as short term liability

'

'

'

'

'

'

'

'

700,000

700,000

'

'

'

Aggregate principal amount of notes issued

'

'

'

'

200,000,000

'

'

'

'

'

'

'

'

Interest rate (as a percent)

2.50%

2.50%

'

2.50%

'

'

'

'

'

'

'

'

'

Estimated fair value of the Notes

$271,200,000

$271,200,000

'

'

'

$271,200,000

'

'

'

'

'

'

'

Accounts_Receivable_Net_Detail

Accounts Receivable, Net (Details) (USD $)	9 Months Ended	12 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Accounts Receivable, Net	'	'
Net Accounts receivable	10,873	6,842
Accounts Receivable [Member] | Credit Concentration Risk [Member] | Amerisource Bergen Drug Corporation [Member]	'	'
Customers representing greater than 10% of accounts receivable balances	'	'
Accounts receivable by major customer (as a percent)	51.00%	43.00%
Accounts Receivable [Member] | Credit Concentration Risk [Member] | McKesson Corporation [Member]	'	'
Customers representing greater than 10% of accounts receivable balances	'	'
Accounts receivable by major customer (as a percent)	26.00%	29.00%
Accounts Receivable [Member] | Credit Concentration Risk [Member] | Cardinal Health Inc [Member]	'	'
Customers representing greater than 10% of accounts receivable balances	'	'
Accounts receivable by major customer (as a percent)	15.00%	19.00%

Inventories_Details

Inventories (Details) (USD $)	9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2013
Inventories	'	'	'
Raw materials	$4,341	'	$3,157
Work in process	7,158	'	8,322
Finished goods	8,081	'	5,738
Total inventories	19,580	'	17,217
Inventories disclosure	'	'	'
Inventory expensed	1,119	502	'
Cost of Sales [Member]	'	'	'
Inventories disclosure	'	'	'
Inventory expensed	400	'	'
Research and Development Expense [Member]	'	'	'
Inventories disclosure	'	'	'
Inventory expensed	$700	'	'

Property_and_Equipment_Net_Det

Property and Equipment, Net (Details) (USD $)	9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2013
Property and Equipment	'	'	'
Property and Equipment, gross	$2,431	'	$2,342
Less - accumulated depreciation	-849	'	-496
Property and equipment, net	1,582	'	1,846
Additions to leasehold improvements, furniture and fixtures	144	1,206	'
Furniture and Fixtures [Member]	'	'	'
Property and Equipment	'	'	'
Property and Equipment, gross	1,509	'	1,536
Leasehold Improvements [Member]	'	'	'
Property and Equipment	'	'	'
Property and Equipment, gross	430	'	430
Laboratory and Production Equipment [Member]	'	'	'
Property and Equipment	'	'	'
Property and Equipment, gross	$492	'	$376

Business_Combination_Details

Business Combination (Details) (Licensing Agreements [Member], USD $)	0 Months Ended	1 Months Ended	9 Months Ended
	Jun. 06, 2013	Jun. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Assets Acquired	'	'	'	'
Acquired finite-lived intangible assets	$16,900,000	'	16,600,000	'
PlasmaTech Biopharmaceuticals Inc Member	'	'	'	'
Business Combination	'	'	'	'
Upfront payment in consideration of license	'	3,300,000	'	'
Consideration:	'	'	'	'
Cash	3,434,000	'	'	'
Acquisition-related contingent consideration	13,700,000	'	'	'
Total consideration	17,134,000	'	'	'
Fair value inputs	'	'	'	'
Period over which estimated undiscounted royalty amounts could be paid	'	'	'10 years	'
Assets Acquired	'	'	'	'
Acquired finite-lived intangible assets	16,893,000	'	'	'
Inventory	241,000	'	'	'
Net identifiable assets acquired	17,134,000	'	'	'
Acquisition-related costs	'	'	'	800,000
PlasmaTech Biopharmaceuticals Inc Member | Fair Value, Inputs, Level 3 [Member]	'	'	'	'
Fair value inputs	'	'	'	'
Discount rate (as a percent)	'	'	15.00%	'
PlasmaTech Biopharmaceuticals Inc Member | Minimum [Member]	'	'	'	'
Fair value inputs	'	'	'	'
Estimated undiscounted royalty amounts payable	'	'	20,000,000	'
PlasmaTech Biopharmaceuticals Inc Member | Maximum [Member]	'	'	'	'
Fair value inputs	'	'	'	'
Estimated undiscounted royalty amounts payable	'	'	28,000,000	'

Intangible_Assets_Net_Details

Intangible Assets, Net (Details) (Licensing Agreements [Member], USD $)	0 Months Ended	3 Months Ended	9 Months Ended
	Jun. 06, 2013	Sep. 30, 2014	Sep. 30, 2014
Licensing Agreements [Member]	'	'	'
Intangible Assets, Net	'	'	'
Acquired finite-lived intangible assets	$16,900,000	$16,600,000	$16,600,000
Useful life	'10 years	'	'
Amortization of MuGard intangible asset	'	$100,000	$200,000

Accumulated_Other_Comprehensiv2

Accumulated Other Comprehensive Loss (Details) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Changes in accumulated other comprehensive income, net of tax	'	'	'	'
Beginning Balance	($3,259)	($3,935)	($3,491)	($3,247)
Other comprehensive income (loss) before reclassifications	-305	399	-76	-310
Gain reclassified from other accumulated comprehensive loss	9	'	12	21
Ending Balance	($3,555)	($3,536)	($3,555)	($3,536)

Basic_and_Diluted_Net_Income_L2

Basic and Diluted Net Income (Loss) per Share (Details) (USD $)	3 Months Ended		9 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Components of basic and diluted net income (loss) per share	'	'	'	'
Net income (loss)	$1,458	($145)	($7,191)	($5,948)
Weighted average common shares outstanding	21,984	21,691	21,912	21,613
Effect of dilutive securities:	'	'	'	'
Stock options and restricted stock units (in shares)	369	'	'	'
Covertible 2.5% senior notes	1,114	'	'	'
Shares used in calculating dilutive net income (loss) per share (in shares)	23,467	21,691	21,912	21,613
Net income (loss) per share:	'	'	'	'
Basic (in dollars per share)	$0.07	($0.01)	($0.33)	($0.28)
Diluted (in dollars per share)	$0.06	($0.01)	($0.33)	($0.28)
Anti-dilutive securities excluded from the computation of diluted net income (loss) per share	'	'	'	'
Anti-dilutive securities (in shares)	9,684	3,214	11,223	3,214
Adjustments to fair value of contingent consideration	'	'	-2,535	279
Impact of the adjustment on contingent consideration liability to earning per share basic and diluted (USD per share)	'	'	$0.12	'
Impact of the adjustment on contingent consideration liability to earning per share basic (USD per share)	$0.17	'	'	'
Impact of the adjustment on contingent consideration liability to earning per share diluted (USD per share)	$0.16	'	'	'
PlasmaTech Biopharmaceuticals Inc Member	'	'	'	'
Anti-dilutive securities excluded from the computation of diluted net income (loss) per share	'	'	'	'
Adjustments to fair value of contingent consideration	($3,700)	'	($2,500)	'
Employee and Non Employee Stock Option [Member]	'	'	'	'
Anti-dilutive securities excluded from the computation of diluted net income (loss) per share	'	'	'	'
Anti-dilutive securities (in shares)	2,013	2,717	3,081	2,717
Restricted Stock Units (RSUs) [Member]	'	'	'	'
Anti-dilutive securities excluded from the computation of diluted net income (loss) per share	'	'	'	'
Anti-dilutive securities (in shares)	289	497	760	497
Warrant [Member]	'	'	'	'
Anti-dilutive securities excluded from the computation of diluted net income (loss) per share	'	'	'	'
Anti-dilutive securities (in shares)	7,382	'	7,382	'

EquityBased_Compensation_Detai

Equity-Based Compensation (Details) (USD $)

9 Months Ended

1 Months Ended

9 Months Ended

33 Months Ended

9 Months Ended

33 Months Ended

1 Months Ended

9 Months Ended

33 Months Ended

1 Months Ended

In Millions, except Share data, unless otherwise specified

Sep. 30, 2014

31-May-13

31-May-10

31-May-09

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

Aug. 31, 2014

Sep. 30, 2014

Sep. 30, 2014

Aug. 31, 2014

Aug. 31, 2014

plan

Equity Incentive Plan 2007 [Member]

Equity Incentive Plan 2007 [Member]

Equity Incentive Plan 2007 [Member]

Equity Incentive Plan 2007 [Member]

Equity Incentive Plan 2007 [Member]

Equity Incentive Plan 2007 [Member]

Stock Plan 2000 [Member]

Stock Plan 2000 [Member]

Other Equity Compensation Grants [Member]

Other Equity Compensation Grants [Member]

Other Equity Compensation Grants [Member]

Other Equity Compensation Grants [Member]

Other Equity Compensation Grants [Member]

Other Equity Compensation Grants [Member]

Share Based Compensation Award Vesting At Specific Date One Member

Share Based Compensation Award Vesting At Specific Date Two Member

Employee and Non Employee Stock Option [Member]

Employee and Non Employee Stock Option [Member]

Employee and Non Employee Stock Option [Member]

Senior Management [Member]

Employee and Non Employee Stock Option [Member]

Employee and Non Employee Stock Option [Member]

Restricted Stock Units (RSUs) [Member]

Restricted Stock Units (RSUs) [Member]

Restricted Stock Units (RSUs) [Member]

Other Equity Compensation Grants [Member]

Other Equity Compensation Grants [Member]

Minimum [Member]

Maximum [Member]

Senior Management [Member]

Senior Management [Member]

Senior Management [Member]

Senior Management [Member]

Senior Management [Member]

Restricted Stock Units (RSUs) [Member]

Restricted Stock Units (RSUs) [Member]

Senior Management [Member]

Senior Management [Member]

Equity-Based Compensation

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Number of equity compensation plans

2

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Equity compensation plans

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Shares authorized for issuance

'

1,100,000

800,000

600,000

'

'

'

'

'

'

'

'

'

'

'

'

'

Award vesting period

'

'

'

'

'

'

'

'

'

'

'4 years

'

'

'4 years

'

'

'

Number of options and restricted stock units granted since inception (in shares)

'

'

'

'

7,523,252

'

'

2,182,700

'

'

'

'

'

'

'

'

'

Number of stock options expired or terminated since inception (in shares)

'

'

'

'

3,014,117

'

'

1,034,339

'

'

'

'

'

'

'

'

'

Number of restricted stock units forfeited since inception (in shares)

'

'

'

'

'

'

'

1,500

'

'

'

'

'

'

'

'

'

Number of restricted stock units expired since inception (in shares)

'

'

'

'

688,824

'

'

'

'

'

'

'

'

'

'

'

'

Stock options exercised since inception (in shares)

'

'

'

'

314,295

'

'

1,052,045

'

'

'

'

'

'

'

'

'

Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period

'

'

'

'

'

'

'

'

'

'

'

28,750

'

'

'

'

'

Shares of common stock issued pursuant to vested restricted stock units since inception

'

'

'

'

527,546

'

'

42,500

'

'

'

'

'

'

'

'

'

Number of stock options outstanding (in shares)

'

'

'

'

2,423,758

'

'

52,316

'

'

'

'

'

'

'

'

'

Number of restricted stock units outstanding (in shares)

'

'

'

'

554,712

'

'

0

'

'

'

'

'

'

'

'

'

Remaining number of shares available for future grants

'

'

'

'

1,579,800

'

'

0

'

'

'

'

'

'

'

'

'

Expiration term

'

'

'

'

'

'7 years

'10 years

'

'10 years

'

'

'

'

'

'

'

'

Forfeited (in shares)

'

'

'

'

'

'

'

'

'

'

'

-101,250

'

'

'

'

'

Granted (in shares)

'

'

'

'

'

'

'

'

'

1,015,300

165,000

'

195,000

65,300

'

'

'

Vested (in shares)

'

'

'

'

'

'

'

'

'

'

'

'

'

'

-33,750

'

'

Forfeited (in shares)

'

'

'

'

'

'

'

'

'

'

'

'

'

'

-41,250

'

'

Fair value of awards granted

'

'

'

'

'

'

'

'

'

'

'

'

$6.30

'

'

'

'

Expense recognition period

'

'

'

'

'

'

'

'

'

'

'

'

'3 years

'

'

'

'

Vesting rights percentage

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

50.00%

100.00%

EquityBased_Compensation_Detai1

Equity-Based Compensation (Details 2) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Equity-based compensation expense	'	'	'	'
Total equity-based compensation expense	$1,946	$1,665	$6,153	$5,886
Cost of Sales [Member]	'	'	'	'
Equity-based compensation expense	'	'	'	'
Total equity-based compensation expense	32	25	89	83
Research and Development Expense [Member]	'	'	'	'
Equity-based compensation expense	'	'	'	'
Total equity-based compensation expense	466	337	1,274	1,634
Selling, General and Administrative Expenses [Member]	'	'	'	'
Equity-based compensation expense	'	'	'	'
Total equity-based compensation expense	$1,448	$1,303	$4,790	$4,169

Commitments_and_Contingencies_

Commitments and Contingencies (Details) (USD $)	0 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 12, 2014	Sep. 30, 2014	Sep. 30, 2014	Sep. 30, 2014
	Settled Litigation [Member]	Settled Litigation [Member]	Minimum [Member]	Maximum [Member]
Litigation settlement	'	'	'	'
Agreed settlement amount	$3.75	'	'	'
Prepaid expense and other assets recorded relating to settlement amount	'	3.75	'	'
Accrual expenses	'	$3.75	'	'
Patent appeals and market exclusivity	'	'	'	'
Estimated term to defend the validity of patent through the appeals process	'	'	'2 years	'3 years
Ferumoxytol term of data and market exclusivity even if there is no successful outcome from the appeals process	'	'	'8 years	'10 years

Collaborative_Agreements_Detai

Collaborative Agreements (Details) (USD $)

Sep. 30, 2014

Dec. 31, 2013

Apr. 30, 2010

Mar. 31, 2010

Sep. 30, 2014

Sep. 30, 2014

Dec. 31, 2010

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

Dec. 31, 2008

License Development and Commercialization Agreement with Takeda [Member]

License Development and Commercialization Agreement with Takeda [Member]

License Development and Commercialization Agreement with Takeda [Member]

License Development and Commercialization Agreement with Takeda [Member]

License Development and Commercialization Agreement with Takeda [Member]

License Development and Commercialization Agreement with Takeda [Member]

License Development and Commercialization Agreement with Takeda [Member]

License Development and Commercialization Agreement with Takeda [Member]

Collaboration and Exclusive License Agreement with 3SBio Inc [Member]

Collaboration and Exclusive License Agreement with 3SBio Inc [Member]

Maximum [Member]

Upfront Payment And Non Substantive Milestone Payments Received Member

Product Shipped But Not Yet Sold Member

Collaborative Agreements

'

'

'

'

'

'

'

'

'

'

'

'

Upfront payment received

'

'

$60,000,000

'

'

'

'

'

'

'

'

$1,000,000

Additional upfront payment

'

'

'

'

'

'

1,000,000

'

'

'

'

'

Period of recognition of deferred revenues

'

'

'

'10 years

'

'

'

'

'

'

'

'

Milestone payments expected to be received under the agreement

'

'

'

'

'

'

'

186,000,000

'

'

'

'

Deferred revenue recognized in earnings related to upfront payments

'

'

'

'

2,000,000

5,900,000

'

'

'

'

1,000,000

'

Other reimbursement revenues

'

'

'

'

200,000

500,000

'

'

'

'

'

'

Product sales and royalty revenue recognized

'

'

'

'

300,000

700,000

'

'

'

'

'

'

Total upfront payments received

'

'

'

'

'

'

'

'

61,000,000

'

'

'

Total non-substantive milestone payments received

'

'

'

'

'

'

'

'

18,000,000

'

'

'

Deferred revenues

'

'

'

'

'

'

'

'

43,400,000

2,700,000

'

'

Deferred revenues, short-term

9,419,000

8,226,000

'

'

'

'

'

'

7,900,000

1,500,000

'

'

Deferred revenues, long-term

36,682,000

44,534,000

'

'

'

'

'

'

35,500,000

1,200,000

'

'

Deferred costs

'

'

'

'

2,400,000

2,400,000

'

'

'

'

'

'

Deferred costs, short-term

'

'

'

'

1,400,000

1,400,000

'

'

'

'

'

'

Deferred costs, long-term

'

'

'

'

$1,000,000

$1,000,000

'

'

'

'

'

'

Debt_Details

Debt (Details) (USD $)

0 Months Ended

3 Months Ended

9 Months Ended

0 Months Ended

3 Months Ended

9 Months Ended

9 Months Ended

Share data in Millions, except Per Share data, unless otherwise specified

Feb. 13, 2014

Sep. 30, 2014

Sep. 30, 2014

Feb. 28, 2014

Feb. 14, 2014

Sep. 30, 2014

Sep. 30, 2014

Feb. 11, 2014

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

Convertible Debt [Member]

Convertible Debt [Member]

Convertible Debt [Member]

Convertible Debt [Member]

Convertible Debt [Member]

Convertible Debt [Member]

Convertible Debt [Member]

Convertible Debt [Member]

Debt Instrument Convertible Covenant One [Member]

Debt Instrument Convertible Covenant Two [Member]

Debt Instrument Convertible Covenant Two [Member]

Debt Instrument Convertible Covenant Three [Member]

item

Maximum [Member]

Liability component:

'

'

'

'

'

'

'

'

'

'

'

'

Principal

'

$200,000,000

$200,000,000

'

'

'

'

'

'

'

'

'

Less: debt discount, net

'

-34,222,000

-34,222,000

'

'

'

'

'

'

'

'

'

Net carrying amount

'

165,778,000

165,778,000

'

'

165,800,000

165,800,000

'

'

'

'

'

Debt Instrument, Fair Value Disclosure

'

271,200,000

271,200,000

'

'

'

'

'

'

'

'

'

Equity component

'

38,188,000

38,188,000

'

'

'

'

'

'

'

'

'

Net proceeds from issuance of convertible debt

'

'

'

'

193,300,000

'

'

'

'

'

'

'

Aggregate principal amount of notes issued

'

'

'

'

200,000,000

'

'

'

'

'

'

'

Amount pertaining to full exercise of over-allotment of debt by underwriters

'

'

'

'

25,000,000

'

'

'

'

'

'

'

Fees and expenses

'

'

'

'

6,700,000

'

'

'

'

'

'

'

Proceeds used to pay the cost of the bond hedges (after such cost was partially offset by proceeds from the sale of warrants)

'

'

14,100,000

'

14,100,000

'

'

'

'

'

'

'

Interest rate (as a percent)

'

2.50%

2.50%

'

'

2.50%

2.50%

'

'

'

'

'

Initial conversion rate of common stock per $1000 of principal amount of Notes (in shares)

'

'

'

'

'

'

36.9079

'

'

'

'

'

Principal amount used for debt instrument conversion ratio

'

'

'

'

'

1,000

1,000

'

'

1,000

'

1,000

Initial conversion price of convertible notes into common stock (in dollars per share)

'

'

'

'

'

$27.09

$27.09

'

'

'

'

'

Conversion premium (as a percent)

'

'

'

'

'

35.00%

35.00%

'

'

'

'

'

Sale price of common stock (in dollars per share)

'

'

'

'

'

'

'

$20.07

'

'

'

'

Number of days during 30 consecutive trading days in which the closing price of the entity's common stock must exceed or equal the conversion price for the notes to be convertible

'

'

'

'

'

'

'

'

20

'

'

'

Number of consecutive trading days during which the closing price of the entity's common stock must exceed or equal the conversion price for at least 20 days in order for the notes to be convertible

'

'

'

'

'

'

'

'

'30 days

'

'

'

Percentage of the closing sales price of the entity's common stock that the conversion price must exceed or be equal in order for the notes to be convertible

'

'

'

'

'

'

'

'

130.00%

'

'

'

Number of consecutive business days after any five consecutive trading day period during the note measurement period

'

'

'

'

'

'

'

'

'

'5 days

'

'

Number of consecutive trading days before five consecutive business days during the note measurement period

'

'

'

'

'

'

'

'

'

'5 days

'

'

Percentage of product of the last reported sale price of the entity's common stock and the conversion rate of convertible debt instruments

'

'

'

'

'

'

'

'

'

'

98.00%

'

Repurchase price as a percentage of principal amount of notes plus accrued and unpaid interest

'

'

'

'

'

'

100.00%

'

'

'

'

'

Minimum percentage of principal amount held by holders to declare notes due and payable

'

'

'

'

'

'

25.00%

'

'

'

'

'

Percentage of principal amount due and payable in an event of default

'

'

'

'

'

'

100.00%

'

'

'

'

'

Percentage of principal amount due and payable in the event of default, arising out of certain events of bankruptcy, insolvency or reorganization

'

'

'

'

'

'

100.00%

'

'

'

'

'

Maximum period to comply any remedy for specified event of default relating to certain failures

'

'

'

'

'

'

'270 days

'

'

'

'

'

Debt issuance costs allocated to equity component

'

'

1,300,000

'

1,300,000

'

'

'

'

'

'

'

Debt issuance costs allocated to the liability component

'

'

'

'

5,400,000

'

'

'

'

'

'

'

Expected life of the debt

'

'

'

'

'

'

'5 years

'

'

'

'

'

Effective interest rate on liability component (as a percent)

'

'

'

'

'

7.23%

7.23%

'

'

'

'

'

Total interest expense recognized

'

'

'

'

'

'

'

'

'

'

'

'

Contractual interest expense

'

'

'

'

'

1,250,000

3,125,000

'

'

'

'

'

Amortization of debt issuance costs

'

'

'

'

'

234,000

564,000

'

'

'

'

'

Amortization of debt discount

'

'

'

'

'

1,645,000

3,967,000

'

'

'

'

'

Total interest expense

'

3,129,000

7,656,000

'

'

3,129,000

7,656,000

'

'

'

'

'

Convertible Bond Hedge

'

'

'

'

'

'

'

'

'

'

'

'

Common stock covered under convertible bond hedge (in shares)

7.4

'

'

'

'

'

'

'

'

'

'

'

Exercise price (in dollars per unit)

$27.09

'

'

'

'

'

'

'

'

'

'

'

Purchase of convertible bond hedge

'

'

39,760,000

'

'

'

'

'

'

'

'

'

Warrant Transactions

'

'

'

'

'

'

'

'

'

'

'

'

Number of shares of common stock called by warrants

'

'

'

7.4

'

'

'

'

'

'

'

'

Exercise price (in dollars per share)

'

'

'

$34.12

'

'

'

'

'

'

'

'

Exercise price above last reported sale price of common stock (as a percent)

'

'

'

70.00%

'

'

'

'

'

'

'

'

Amount received on warrants sold

'

'

$25,620,000

'

'

'

'

'

'

'

'

'

Stockholders_Equity_Details

Stockholders' Equity (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Feb. 28, 2014
Stockholders' Equity	'	'	'	'	'
Increase in total stockholders' equity	'	'	$24,600,000	'	'
Increase in total stockholders' equity allocated to equity portion of Convertible Notes	38,188,000	'	38,188,000	'	'
Increase in total stockholders' equity allocated to stock-based compensation expense	'	'	6,153,000	5,886,000	'
Increase in total stockholders' equity due to proceeds from exercise of stock options	'	'	2,909,000	1,629,000	'
Increase in total stockholders' equity partially offset by net loss	-1,458,000	145,000	7,191,000	5,948,000	'
Increase in total stockholders' equity partially offset by the cost of the convertible bond hedges, net of the sale of warrants	'	'	14,100,000	'	'
Increase in total stockholders' equity partially offset by debt issuance costs allocated to equity component of the Convertible Notes	'	'	$1,300,000	'	'
Preferred Stock	'	'	'	'	'
Exercise price (in dollars per share)	'	'	'	'	$34.12
Rights [Member]	'	'	'	'	'
Preferred Stock	'	'	'	'	'
Exercise price (in dollars per share)	$80	'	$80	'	'
Exercise price before adjustment (in dollars per share)	'	'	$250	'	'
Percentage of ownership before the NOL Amendment	'	'	20.00%	'	'
Rights [Member] | Minimum [Member]	'	'	'	'	'
Preferred Stock	'	'	'	'	'
Percentage of beneficial ownership to acquire to make the Rights exercisable	'	'	4.99%	'	'

Subsequent_Event_Details

Subsequent Event (Details) (Lumara Health Inc Member, USD $)	0 Months Ended			9 Months Ended	0 Months Ended		9 Months Ended
	Sep. 28, 2014	Sep. 28, 2014	Sep. 30, 2014	Sep. 30, 2014	Sep. 28, 2014	Sep. 28, 2014	Sep. 30, 2014
			Commitment Letter Member	Commitment Letter Member	Subsequent Event [Member]	Subsequent Event [Member]	Subsequent Event [Member]
				Merger Agreement Terminated			Commitment Letter Member
Subsequent event	'	'	'	'	'	'	'
Upfront merger consideration	$675,000,000	'	'	'	$675,000,000	'	'
Amount in cash	600,000,000	'	'	'	600,000,000	'	'
Value in common stocks to pay	75,000,000	'	'	'	'	'	'
Number of common stock used to pay (in shares)	'	'	'	'	3,209,971	'	'
Maximum contingent consideration	'	350,000,000	'	'	'	350,000,000	'
Maximum borrowing capacity	'	'	$340,000,000	'	'	'	'
Maximum number of days for the commitment letter to expire	'	'	'	'5 days	'	'	'
Number of business days for lender to syndicate the loan	'	'	'	'	'	'	'15 days