Amag Pharmaceuticals (AMAG) 10-K 18 Feb 15 2014 FY Annual report Financial data

Document_and_Entity_Informatio

Document and Entity Information (USD $)	12 Months Ended
	Dec. 31, 2014	Feb. 04, 2015	Jun. 30, 2014
Document and Entity Information
Entity Registrant Name	AMAG PHARMACEUTICALS INC.
Entity Central Index Key	792977
Document Type	10-K
Document Period End Date	31-Dec-14
Amendment Flag	FALSE
Current Fiscal Year End Date	-19
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Filer Category	Accelerated Filer
Entity Public Float			$453,000,000
Entity Common Stock, Shares Outstanding		25,615,978
Document Fiscal Year Focus	2014
Document Fiscal Period Focus	FY

Consolidated_Balance_Sheets

Consolidated Balance Sheets (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Current assets:
Cash and cash equivalents	$119,296	$26,986
Investments	24,890	186,803
Accounts receivable, net	38,172	6,842
Inventories	40,610	17,217
Receivable from collaboration	4,518	278
Deferred tax assets	32,094
Prepaid and other current assets	14,456	3,396
Restricted cash		2,883
Total current assets	274,036	244,405
Property and equipment, net	1,519	1,846
Goodwill	205,824
Intangible assets, net	887,908	16,844
Restricted cash	2,397	400
Other long-term assets	17,249	1,964
Total assets	1,388,933	265,459
Current liabilities:
Accounts payable	7,301	2,629
Accrued expenses	80,811	22,266
Current portion of long-term debt	34,000
Deferred revenues	44,376	8,226
Total current liabilities	166,488	33,121
Long-term liabilities:
Long-term debt, net	293,905
Convertible 2.5% senior notes, net	167,441
Acquisition-related contingent consideration	217,984	13,609
Deferred income tax liability	77,619
Deferred revenues		44,534
Other long-term liabilities	5,543	1,787
Total liabilities	928,980	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; 25,599,550 and 21,772,571 shares issued and outstanding at December 31, 2014 and 2013, respectively	256	218
Additional paid-in capital	793,757	641,941
Accumulated other comprehensive loss	-3,617	-3,491
Accumulated deficit	-330,443	-466,260
Total stockholders' equity	459,953	172,408
Total liabilities and stockholders' equity	$1,388,933	$265,459

Consolidated_Balance_Sheets_Pa

Consolidated Balance Sheets (Parenthetical) (USD $)	Dec. 31, 2014	Dec. 31, 2013
Consolidated Balance Sheets
Interest rate (as a percent)	2.50%	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	25,599,550	21,772,571
Common stock, shares outstanding	25,599,550	21,772,571

Consolidated_Statements_of_Ope

Consolidated Statements of Operations (USD $)	12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Revenues:
U.S. product sales, net	$108,795	$71,362	$58,287
License fee and other collaboration revenues	10,886	8,385	26,475
Other product sales and royalties	4,703	1,109	616
Total revenues	124,384	80,856	85,378
Costs and expenses:
Cost of product sales	20,306	11,960	14,220
Research and development expenses	24,160	20,564	33,296
Selling, general and administrative expenses	72,254	59,167	53,071
Acquisition-related costs	9,478	782
Restructuring expenses	2,023		2,215
Total costs and expenses	128,221	92,473	102,802
Operating loss	-3,837	-11,617	-17,424
Other income (expense):
Interest expense	-14,697
Interest and dividend income, net	975	1,051	1,286
Gains on sale of assets	103	924
Gains (losses) on investments, net	114	40	-1,466
Total other income (expense)	-13,505	2,015	-180
Net income (loss) before income taxes	-17,342	-9,602	-17,604
Income tax benefit	153,159		854
Net income (loss)	$135,817	($9,602)	($16,750)
Net Income (Loss) per share:
Basic (in dollars per share)	$6.06	($0.44)	($0.78)
Diluted (in dollars per share)	$5.45	($0.44)	($0.78)
Weighted average shares outstanding used to compute net income (loss) per share:
Basic (in shares)	22,416	21,703	21,392
Diluted (in shares)	25,225	21,703	21,392

Consolidated_Statements_of_Com

Consolidated Statements of Comprehensive Income (Loss) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Consolidated Statements of Comprehensive Income (Loss)
Net income (loss)	$135,817	($9,602)	($16,750)
Unrealized gains (losses) on securities:
Holding gains (losses) arising during period, net of tax	-191	-268	129
Reclassification adjustment for (gains) losses included in net income (loss)	65	24	1,466
Net unrealized gains (losses) on securities	-126	-244	1,595
Total comprehensive income (loss)	$135,691	($9,846)	($15,155)

Consolidated_Statements_of_Sto

Consolidated Statements of Stockholders' Equity (USD $)	Common Stock	Additional Paid-in Capital	Accumulated Other Comprehensive Income (Loss)	Retained Earnings	Total
In Thousands, unless otherwise specified
Balance at Dec. 31, 2011	$213	$625,133	($4,842)	($439,908)	$180,596
Balance (in shares) at Dec. 31, 2011	21,306
Increase (Decrease) in Stockholders' Equity
Net shares issued in connection with the exercise of stock options and vesting of restricted stock units	2	98			100
Net shares issued in connection with the exercise of stock options and restricted stock units (in shares)	178
Shares issued in connection with employee stock purchase plan		270			270
Shares issued in connection with employee stock purchase plan (in shares)	23
Non-cash equity-based compensation		6,986			6,986
Unrealized gains (losses) on securities, net of tax of $0.9 million			1,595		1,595
Net income (loss)				-16,750	-16,750
Balance at Dec. 31, 2012	215	632,487	-3,247	-456,658	172,797
Balance (in shares) at Dec. 31, 2012	21,507
Increase (Decrease) in Stockholders' Equity
Net shares issued in connection with the exercise of stock options and vesting of restricted stock units	3	1,274			1,277
Net shares issued in connection with the exercise of stock options and restricted stock units (in shares)	252
Shares issued in connection with employee stock purchase plan		176			176
Shares issued in connection with employee stock purchase plan (in shares)	14
Non-cash equity-based compensation		8,004			8,004
Unrealized gains (losses) on securities, net of tax of $0.9 million			-244		-244
Net income (loss)				-9,602	-9,602
Balance at Dec. 31, 2013	218	641,941	-3,491	-466,260	172,408
Balance (in shares) at Dec. 31, 2013	21,773
Increase (Decrease) in Stockholders' Equity
Equity component of Convertible Notes, net of issuance costs		36,907			36,907
Purchase of convertible bond hedges		-39,760			-39,760
Proceeds from issuance of warrants		25,620			25,620
Net shares issued in connection with the acquisition of Lumara Health	32	111,932			111,964
Net shares issued in connection with the acquisition of Lumara Health (in shares)	3,210
Net shares issued in connection with the exercise of stock options and vesting of restricted stock units	6	8,492			8,498
Net shares issued in connection with the exercise of stock options and restricted stock units (in shares)	617
Non-cash equity-based compensation		8,625			8,625
Unrealized gains (losses) on securities, net of tax of $0.9 million			-126		-126
Net income (loss)				135,817	135,817
Balance at Dec. 31, 2014	$256	$793,757	($3,617)	($330,443)	$459,953
Balance (in shares) at Dec. 31, 2014	25,600

Consolidated_Statements_of_Sto1

Consolidated Statements of Stockholders' Equity (Parenthetical) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2012
Consolidated Statements of Stockholders' Equity
Unrealized gains (losses) on securities, tax	$0.90

Consolidated_Statements_of_Cas

Consolidated Statements of Cash Flows (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Cash flows from operating activities:
Net income (loss)	$135,817	($9,602)	($16,750)
Adjustments to reconcile net income ( loss) to net cash provided by (used in) operating activities:
Depreciation and amortization	6,984	3,085	3,084
Impairment loss on assets held for sale			1,100
Amortization of premium/discount on purchased securities	2,080	2,758	2,808
Write-down of inventory to net realizable value	1,309	2,175	1,822
Non-cash equity-based compensation expense	8,625	8,004	7,024
Amortization of debt discount and debt issuance costs	6,870
Non-cash income tax benefit			-854
Gains on sale of assets	-103	-924
(Gains) losses on investments, net	-114	-40	1,466
Change in fair value of contingent consideration	-681	1,074
Deferred income taxs	-153,159
Changes in operating assets and liabilities:
Accounts receivable, net	3,588	-432	-478
Inventories	-1,360	-1,040	4,069
Receivable from collaboration	-4,239	-15	165
Prepaid and other current assets	2,331	2,817	75
Other long-term assets	1,964	-1,964
Accounts payable and accrued expenses	10,694	-5,730	-12,195
Deferred revenues	-8,384	-6,694	7,912
Other long-term liabilities	-808	-246	-405
Total adjustments	-124,403	2,828	15,593
Net cash provided by (used in) operating activities	11,414	-6,774	-1,157
Cash flows from investing activities:
Acquisition of Lumara Health, net of acquired cash	-595,602
Proceeds from sales or maturities of investments	223,568	106,030	133,061
Purchase of investments	-63,747	-115,046	-149,406
Acquisition of MuGard Rights and inventory		-3,434
Proceeds from sale of assets	103	2,970
Change in restricted cash	2,883	-2,823
Capital expenditures	-147	-1,632	-47
Net cash (used in) investing activities	-432,942	-13,935	-16,392
Cash flows from financing activities:
Payment of contingent consideration	-270	-51
Proceeds from term loan	327,509
Proceeds from issuance of convertible 2.5% senior notes	200,000
Payment of debt issuance costs	-7,760
Proceeds from issuance of warrants	25,620
Purchase of convertible bond hedges	-39,760
Proceeds from the exercise of stock options	8,499	1,277	98
Proceeds from the issuance of common stock under ESPP		176	270
Net cash provided by financing activities	513,838	1,402	368
Net increase (decrease) in cash and cash equivalents	92,310	-19,307	-17,181
Cash and cash equivalents at beginning of the year	26,986	46,293	63,474
Cash and cash equivalents at end of the year	119,296	26,986	46,293
Supplemental data of cash flow information:
Interest paid on convertible 2.5% senior notes	2,500
Non-cash investing activities:
Accrued construction in progress	0		228
Fair value of acquisition-related contingent consideration	205,000	13,700
Fair value of common stock issued in connection with the Lumara Health acquisition	$111,964

Description_of_Business

Description of Business	12 Months Ended
	Dec. 31, 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 Makena® (hydroxyprogesterone caproate injection), Feraheme® (ferumoxytol) Injection for Intravenous ("IV") use and MuGard® Mucoadhesive Oral Wound Rinse.
	On November 12, 2014, we acquired Lumara Health Inc. ("Lumara Health"), a privately held pharmaceutical company specializing in women's health, for approximately $600.0 million in upfront cash consideration (subject to finalization of certain adjustments related to Lumara Health's financial position at the time of closing, including adjustments related to net working capital, net debt and transaction expenses) and approximately 3.2 million shares of our common stock having a fair value of approximately $112.0 million at the time of closing (the "Lumara Agreement"). The Lumara Agreement includes future contingent payments of up to $350.0 million in cash (or upon mutual agreement between us and the former Lumara Health security holders, future contingent payments may also be made in common stock or some combination thereof) payable by us to the former Lumara Health security holders based upon the achievement of certain sales milestones through calendar year 2019. In connection with the acquisition of Lumara Health, we acquired Makena, 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. We sell Makena to specialty pharmacies and distributors, who, in turn sell Makena to healthcare providers, hospitals, government agencies and integrated delivery systems. Additional details regarding the acquisition of Lumara Health can be found in Note C, "Business Combinations," to our consolidated financial statements included in this Annual Report on Form 10-K.
	We also market and sell 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 iron deficiency anemia ("IDA") in adult patients with chronic kidney disease ("CKD"). We began selling Feraheme in the U.S. in July 2009 through our 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 the European Union ("EU"), Canada and Switzerland 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"). On December 29, 2014, we entered into an agreement with Takeda to terminate the Amended Takeda Agreement and we will regain all worldwide development and commercialization rights for Feraheme following the transfer of marketing authorizations (the "Takeda Termination Agreement"). Additional details regarding the Takeda Termination Agreement can be found in Note R, "Collaborative Agreements". Under the Amended Takeda Agreement, Takeda had an exclusive license to market and sell ferumoxytol in the EU, Canada and Switzerland, as well as certain other geographic territories. The EU marketing authorization for Rienso is valid in the 28 EU Member States as well as in Iceland, Liechtenstein and Norway. We have recently come to a mutual decision with Takeda to initiate withdrawal of the marketing authorization for Rienso in the EU and Switzerland. We are also currently assessing the commercial opportunity for Feraheme in Canada. The trade name for ferumoxytol in Canada is Feraheme and outside of the U.S. and Canada the trade name is Rienso.
	We are subject to risks common to companies in the pharmaceutical industry including, but not limited to (as such risks pertain to our business) our dependence on the success of our product portfolio and maintaining commercialization of our products, including Makena and Feraheme; intense competition, including from generic products; maintaining the proprietary nature of our technology; our dependence upon third party manufacturers; our reliance on other third parties in our business, including to conduct our clinical trials and undertake our product distribution; our reliance on and the extent of reimbursement from third parties for the use of our products, including Makena's high Medicaid reimbursement concentration; the impact of Makena's loss of orphan drug exclusivity in February 2018; competition from compounded pharmacies; our ability to implement Makena's lifecycle management program; perceptions related to pricing and access for Makena; post-marketing commitments for Makena; limitations on Feraheme sales given its narrow CKD indication and the potential impact on sales of any actual or perceived safety problems; our ability to receive regulatory approval for Feraheme in the broader IDA indication and Feraheme's ability to compete in such market even if regulatory approval is pursued and received; our customer concentration, especially with regard to Feraheme; the impact of the termination of our license arrangement with Takeda and our commercialization efforts, if any and including cessation thereof, for Feraheme outside of the U.S., including the impact on U.S. sales; uncertainties regarding federal and state legislative initiatives; potential inability to obtain raw or other materials; our potential inadvertent failure to comply with federal, state or foreign healthcare fraud and abuse laws, marketing disclosure laws or other federal, state or foreign laws and regulations; uncertainties regarding reporting and payment obligations under government pricing programs and our level of indebtedness, our access to sufficient capital, the availability of net operating loss carryforwards and other tax assets, employee retention, our ability to be profitable in the future, the potential fluctuation of our operating results, potential differences between actual future results and the estimates or assumptions used by us in preparation of our consolidated financial statements, the volatility of our stock price, potential litigation, including securities and product liability suits and the impact of market overhang on our stock price.
	Throughout this Annual Report on Form 10-K, 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).

Summary_of_Significant_Account

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2014
Summary of Significant Accounting Policies
Summary of Significant Accounting Policies
	B.    SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES
	Use of Estimates and Assumptions
	The preparation of consolidated financial statements in conformity with accounting principles generally accepted in the U.S. ("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 to determine amounts and values of, but are not limited to: revenue related to product sales and collaboration agreements; product sales allowances and accruals; potential other-than-temporary impairment of investments; acquisition date fair value and subsequent fair value estimates used to assess impairment of long-lived assets, including goodwill, in-process research and development ("IPR&D") and other intangible assets; contingent consideration; debt obligations; accrued expenses; income taxes and equity-based compensation expense. Actual results could differ materially from those estimates.
	Basis of Presentation and Principles of Consolidation
	The accompanying consolidated financial statements have been prepared in conformity with GAAP and include the accounts of our wholly owned subsidiaries. All intercompany balances and transactions have been eliminated in consolidation. As of November 12, 2014 (the "Lumara Acquisition Date"), the operating results of Lumara Health have been consolidated with ours. See Note C, "Business Combinations," for additional information.
	Cash and Cash Equivalents
	Cash and cash equivalents consist 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 December 31, 2014, substantially all of our cash and cash equivalents were held in either commercial bank accounts or money market funds.
	Investments
	We account for and classify our investments as either "available-for-sale," "trading," or "held-to-maturity," in accordance with current guidance related to the accounting and classification of certain investments in debt and equity securities. The determination of the appropriate classification by us is based on a variety of factors, including management's intent at the time of purchase. As of December 31, 2014 and 2013, all of our investments were classified as available-for-sale securities.
	Available-for-sale securities are those securities which we view as available for use in current operations, if needed. We generally classify our available-for-sale securities as short-term investments, even though the stated maturity date may be one year or more beyond the current balance sheet date. Available-for-sale investments are stated at fair value with their unrealized gains and losses included as a separate component of stockholders' equity entitled "Accumulated other comprehensive loss," until such gains and losses are realized or until an unrealized loss is considered other-than-temporary.
	We recognize and report other-than-temporary impairments of our debt securities in accordance with current accounting guidance, which requires that for debt securities with a decline in fair value below amortized cost basis, an other-than-temporary impairment exists if (a) we have the intent to sell the security or (b) it is more likely than not that we will be required to sell the security prior to recovery of its amortized cost basis. If either of these conditions is met, we recognize the difference between the amortized cost of the security and its fair value at the impairment measurement date in our consolidated statement of operations. If neither of these conditions is met, we must perform additional analyses to evaluate whether the unrealized loss is associated with the creditworthiness of the security rather than other factors, such as interest rates or market factors. These factors include evaluation of the security, issuer and other factors such as the duration of the period that, and extent to which, the fair value was less than cost basis, the financial health of and business outlook for the issuer, including industry and sector performance, operational and financing cash flow factors, overall market conditions and trends, underlying collateral, whether we have a favorable history in redeeming similar securities at prices at or above fair value, and credit ratings with respect to our investments provided by investments ratings agencies. If we determine from this analysis that we do not expect to receive cash flows sufficient to recover the entire amortized cost of the security, a credit loss exists. In this situation, the impairment is considered other-than-temporary and is recognized in our consolidated statement of operations.
	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 acquisition-related contingent consideration.
	We also analyze when the volume and level of activity for an asset or liability have significantly decreased and when circumstances indicate that a transaction may not be considered orderly. In order to determine whether the volume and level of activity for an asset or liability have significantly decreased, we assess current activity as compared to normal market activity for the asset or liability. We rely on many factors such as trading volume, trading frequency, the levels at which market participants indicate their willingness to buy and sell our securities, as reported by market participants, and current market conditions. Using professional judgment and experience, we evaluate and weigh the relevance and significance of all applicable factors to determine if there has been a significant decrease in the volume and level of activity for an asset, group of similar assets or liabilities. Similarly, in order to identify transactions that are not orderly, we take into consideration the activity in the market which can influence the determination and occurrence of an orderly transaction. Also, we inquire as to whether there may have been restrictions on the marketing of the security to a single or limited number of participants. Where possible, we assess the financial condition of the seller to determine whether observed transactions may have been forced. If there is a significant disparity between the trading price for a security held by us as compared to the trading prices of similar recent transactions, we consider whether this disparity is an indicator of a disorderly trade. Using professional judgment and experience, we evaluate and weigh the relevance and significance of all applicable factors to determine if the evidence suggests that a transaction or group of similar transactions is not orderly. Based upon these procedures, we determined that market activity for our assets appeared normal and that transactions did not appear disorderly as of December 31, 2014 and 2013.
	Inventory
	Inventory is stated at the lower of cost or market (net realizable value), with approximate cost being determined on a first-in, first-out basis. Prior to initial approval from the FDA or other regulatory agencies, we expense costs relating to the production of inventory in the period incurred. After such time as the product receives initial regulatory approval, we begin to capitalize the inventory costs related to the product. We continue to expense costs associated with clinical trial material as research and development expense.
	On a quarterly basis, we analyze our inventory levels to determine whether we have any obsolete, expired, or excess inventory. If any inventory is expected to expire prior to being sold, has a cost basis in excess of its net realizable value, is in excess of expected sales requirements as determined by internal sales forecasts, or fails to meet commercial sale specifications, the inventory is written-down through a charge to cost of product sales. The determination of whether inventory costs will be realizable requires estimates by management of future expected inventory requirements, based on sales forecasts. Once packaged, Feraheme currently has a shelf-life of five years in the U.S. and between two and three years outside of the U.S. and Makena has a shelf-life of three years. As a result of comparison to internal sales forecasts, we expect to fully realize the carrying value of our current Feraheme and Makena finished goods inventory. If actual market conditions are less favorable than those projected by management, inventory write-downs may be required. Charges for inventory write-downs are not reversed if it is later determined that the product is saleable.
	Restricted Cash
	As of December 31, 2014 and 2013, we classified $2.4 million and $3.3 million as restricted cash, respectively. The $2.4 million in our December 31, 2014 restricted cash balances includes $2.0 million held in a restricted fund previously established by Lumara Health in connection with its Chapter 11 plan of reorganization to pay potential claims against its former directors and officers and a $0.4 million security deposit delivered to the landlord of our Waltham, Massachusetts headquarters in the form of an irrevocable letter of credit. Included in the $3.3 million restricted cash balance as of December 31, 2013 was a $2.9 million escrow payment related to a business development transaction that we did not complete as well as the $0.4 million security deposit related to our Waltham, Massachusetts headquarters described above. The escrow payment was returned to us in January 2014 and as such was classified as short-term as of December 31, 2013.
	Property and Equipment
	Property and equipment are recorded at cost and depreciated when placed into service using the straight-line method based on their estimated useful lives. Our laboratory and production equipment and furniture and fixtures are being depreciated over five years. Furniture, fixtures, and leasehold improvements associated with our facility lease are being depreciated over the shorter of their useful lives or the remaining life of the original lease (excluding optional lease renewal terms).
	Costs for capital assets not yet placed in service are capitalized on our balance sheets and will be depreciated in accordance with the above guidelines once placed into service. Costs for maintenance and repairs are expensed as incurred. Upon sale or other disposition of property and equipment, the cost and related depreciation are removed from the accounts and any resulting gain or loss is charged to our consolidated statement of operations. Long-lived assets to be held and used are evaluated for impairment whenever events or changes in circumstances indicate that the carrying value of the asset may not be recoverable. Determination of recoverability is based on an estimate of undiscounted future cash flows resulting from the use of the asset (asset group) and its eventual disposition. In the event such cash flows are not expected to be sufficient to recover the carrying amount of the assets, the assets are written down to their estimated fair values. Assets classified as held for sale are no longer subject to depreciation and are recorded at the lower of carrying value or estimated net realizable value.
	Business Combinations
	We account for acquired businesses using the acquisition method of accounting, which requires that assets acquired and liabilities assumed be recognized at their estimated fair values as of the acquisition date. Acquisition-related costs are expensed as incurred. Any excess of the consideration transferred over the estimated fair values of the net assets acquired is recorded as goodwill.
	Acquisition-Related Contingent Consideration
	Contingent consideration arising from a business combination is included as part of the purchase price and is recognized at fair value as of the acquisition date. Subsequent to the acquisition date, we measure contingent consideration arrangements at fair value for each period until the contingency is resolved. These changes in fair value are recognized in our consolidated statements of operations. Changes in fair values reflect new information about the likelihood of the payment of the contingent consideration and the passage of time.
	Goodwill and Intangible Assets
	Goodwill represents the excess purchase price paid in a business combination over the fair value of identifiable net assets acquired. Goodwill is not amortized, but is reviewed for impairment on an annual basis or more frequently if indicators of impairment are present. We determine whether goodwill may be impaired by comparing the carrying value of the reporting unit, including goodwill, to the fair value of the reporting unit. If the fair value is less than the carrying amount, a more detailed analysis is performed to determine whether goodwill is impaired. The impairment loss, if any, is measured as the excess of the carrying value of the goodwill over the implied value of the goodwill and is recorded in our consolidated statements of operations.
	Finite-lived intangible assets are amortized to their estimated residual values over their estimated useful lives and reviewed for impairment if certain events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. When such facts and circumstances exist, management compares the projected undiscounted future cash flows associated with the asset over its estimated useful life against the carrying amount. The impairment loss, if any, is measured as the excess of the carrying amount of the asset over its fair value.
	Acquired IPR&D represents the fair value assigned to research and development assets that we acquire that have not been completed at the date of acquisition. The fair value of IPR&D acquired in a business combination is capitalized on our consolidated balance sheet at the acquisition-date fair value. IPR&D is not amortized, but is reviewed for impairment on an annual basis or more frequently if indicators of impairment are present, until completion or abandonment of the projects. If we determine that IPR&D becomes impaired or is abandoned, the carrying value of the IPR&D is written down to its fair value with the related impairment charge recognized in our consolidated statement of operations in the period in which the impairment occurs. Upon successful completion of each project and launch of the product, we will make a separate determination of the estimated useful life of the IPR&D intangible asset and the related amortization will be recorded as an expense prospectively over its estimated useful life.
	The projected discounted cash flow models used to estimate our IPR&D reflect significant assumptions regarding the estimates a market participant would make in order to evaluate a drug development asset including the following:
	•	Probability of successfully completing clinical trials and obtaining regulatory approval;
	•	Market size, market growth projections, and market share;
	•	Estimates regarding the timing of and the expected costs to advance our clinical programs to commercialization;
	•	Estimates of future cash flows from potential product sales; and
	•	a discount rate.
	Patents
	We expense all patent-related costs as incurred.
	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. Product Sales, Net
	We record product sales allowances and accruals related to prompt payment discounts, chargebacks, government and other rebates, distributor, wholesaler and group purchasing organization ("GPO") fees, and product returns as a reduction of revenue in our consolidated statement of operations at the time product sales are recorded. Calculating these gross to net sales adjustments involves estimates and judgments based primarily on actual product sales data, forecasted customer buying patterns, and market research data related to utilization rates by various end-users. In addition, we also monitor our distribution channel to determine whether additional allowances or accruals are required based on inventory in our sales channel.
	An analysis of our U.S. product sales allowances and accruals for the years ended December 31, 2014, 2013 and 2012 is as follows (in thousands):
			Years Ended December 31,
			2014			2013			2012
	Provision for U.S. product sales allowances and accruals
	Discounts and chargebacks		$	55,420		$	37,098		$	26,517
	Government and other rebates			25,091			10,868			6,058
	Medicaid rebate reserve adjustment			—			(568	)		(621	)
	Returns			(1,160	)		952			(1,516	)
	Total provision for U.S. product sales allowances and accruals		$	79,351		$	48,350		$	30,438
	Total gross U.S. product sales		$	188,146		$	119,712		$	88,725
	Total provision for U.S. product sales allowances and accruals as a percent of total gross U.S. product sales			42%			40%			34%
	The increases in discounts and chargebacks and government and other rebates primarily reflects the addition of the Makena product to our portfolio as a result of the November 2014 acquisition of Lumara Health. In addition, as discussed below, we reduced our reserve for Feraheme product returns by approximately $1.8 million and $2.2 million during 2014 and 2012, respectively.
Classification of U.S. Product Sales Allowances and Accruals
Product sales allowances and accruals are primarily comprised of both direct and indirect fees, discounts and rebates and provisions for estimated product returns. Direct fees, discounts and rebates are contractual fees and price adjustments payable to wholesalers, specialty distributors and other customers that purchase products directly from us. Indirect fees, discounts and rebates are contractual price adjustments payable to healthcare providers and organizations, such as certain physicians, clinics, hospitals, GPOs, and dialysis organizations that typically do not purchase products directly from us but rather from wholesalers and specialty distributors. In accordance with guidance related to accounting for fees and consideration given by a vendor to a customer, including a reseller of a vendor's products, these fees, discounts and rebates are presumed to be a reduction of the selling price. Product sales allowances and accruals are based on definitive contractual agreements or legal requirements (such as Medicaid laws and regulations) related to the purchase and/or utilization of the product by these entities and are recorded in the same period that the related revenue is recognized. We estimate product sales allowances and accruals using either historical, actual and/or other data, including estimated patient usage, applicable contractual rebate rates, contract performance by the benefit providers, other current contractual and statutory requirements, historical market data based upon experience of our products and other products similar to them, specific known market events and trends such as competitive pricing and new product introductions, current and forecasted customer buying patterns and inventory levels, and the shelf life of our products. As part of this evaluation, we also review changes to federal and other legislation, changes to rebate contracts, changes in the level of discounts, and changes in product sales trends. Although allowances and accruals are recorded at the time of product sale, certain rebates are typically paid out, on average, up to three months or longer after the sale.
Allowances against receivable balances primarily relate to prompt payment discounts, provider chargebacks and certain government agency rebates and are recorded at the time of sale, resulting in a reduction in product sales revenue and the reporting of product sales receivables net of allowances. Accruals related to Medicaid and provider volume rebates, wholesaler and distributor fees, GPO fees, other discounts to healthcare providers and product returns are recorded at the time of sale, resulting in a reduction in product sales revenue and the recording of an increase in accrued expenses.
Discounts
We typically offer a 2% prompt payment discount to our customers as an incentive to remit payment in accordance with the stated terms of the invoice, generally thirty days. Because we anticipate that those customers who are offered this discount will take advantage of the discount, we accrue 100% of the prompt payment discount, at the time of sale, based on the gross amount of each invoice. We adjust the accrual quarterly to reflect actual experience.
Chargebacks
Chargeback reserves represent our estimated obligations resulting from the difference between the prices at which we sell our products to wholesalers and the sales price ultimately paid to wholesalers under fixed price contracts by third-party payers, including governmental agencies. We determine our chargeback estimates based on actual product sales data and forecasted customer buying patterns. Actual chargeback amounts are determined at the time of resale to the qualified healthcare provider, and we generally issue credits for such amounts within several weeks of receiving notification from the wholesaler. Estimated chargeback amounts are recorded at the time of sale, and we adjust the allowance quarterly to reflect actual experience.
Government and Other Rebates
Government and other rebate reserves relate to our reimbursement arrangements with state Medicaid programs, and contractual or performance rebate agreements with certain classes of trade. We determine our estimates for Medicaid rebates, if applicable, based on actual product sales data and our historical product claims experience. In estimating these reserves, we provide for a Medicaid rebate associated with both those expected instances where Medicaid will act as the primary insurer as well as in those instances where we expect Medicaid will act as the secondary insurer. For rebates associated with reaching defined performance goals, we determine our estimates using actual product sales data and forecasted customer buying and utilization patterns. Rebate amounts generally are invoiced quarterly and are paid in arrears, and we expect to pay such amounts within several weeks of notification by the Medicaid or provider entity. Estimated government and other rebates are recorded at the time of sale and, with the exception of Medicaid as discussed below, we adjust the accrual quarterly to reflect actual experience.
During 2013 and 2012, we revised our estimated Feraheme Medicaid reserve rate based on actual product-specific rebate claims received since the 2009 launch of Feraheme, our expectations of state level activities, and estimated rebate claims not yet submitted, which resulted in a reduction of our then estimated Medicaid rebate reserve related to prior period Feraheme sales of $0.6 million in each of the respective years. These changes in estimates were reflected as an increase in our net product sales for 2013 and 2012 and resulted in reductions to our gross to net percentages in those periods. The reduction of our estimated Medicaid rebate reserve had an impact of $0.03 per basic and diluted share for each of the respective years. We regularly assess our Medicaid reserve balance and the rate at which we accrue for claims against product sales. If we determine in future periods that our actual rebate experience is not indicative of expected claims, or if 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 net product sales in the period of the adjustment and could be significant.
Distributor/Wholesaler and Group Purchasing Organization Fees
Fees under our arrangements with distributors and wholesalers are usually based upon units of product purchased during the prior month or quarter and are usually paid by us within several weeks of our receipt of an invoice from the wholesaler or distributor, as the case may be. Fees under our arrangements with GPOs are usually based upon member purchases during the prior quarter and are generally billed by the GPO within 30 days after period end. Current accounting standards related to consideration given by a vendor to a customer, including a reseller of a vendor's products, specify that cash consideration given by a vendor to a customer is presumed to be a reduction of the selling price of the vendor's products or services and therefore should be characterized as a reduction of revenue. Consideration should be characterized as a cost incurred if we receive, or will receive, an identifiable benefit (goods or services) in exchange for the consideration and we can reasonably estimate the fair value of the benefit received. Because the fees we pay to wholesalers do not meet the foregoing conditions to be characterized as a cost, we have characterized these fees as a reduction of revenue and have included them in government and other rebates in the table above. We generally pay such amounts within several weeks of our receipt of an invoice from the distributor, wholesaler or GPO. Accordingly, we accrue the estimated fee due at the time of sale, based on the contracted price invoiced to the customer. We adjust the accrual quarterly to reflect actual experience.
Product Returns
Consistent with industry practice, we generally offer our wholesalers, specialty distributors and other customers a limited right to return our products based on the product's expiration date. Currently the expiration dates for Feraheme in the U.S., Makena and MuGard are five years, three years and three years, respectively. 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 of the product, the expense to store our products, and/or that our products are readily available for distribution. 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 2014, we reduced our reserve for Feraheme product returns by approximately $1.8 million, primarily as a result of a lower than expected rate of product returns. We did not significantly adjust our reserve for product returns during 2013. During 2012, we reduced our reserve for Feraheme product returns by approximately $2.2 million, primarily as a result of a lower than expected rate of product returns as well as the lapse of the product return period on certain manufactured Feraheme lots. The reduction of our reserve had an impact of increasing our 2014 net income by $0.12 and $0.14 per basic and diluted share, respectively, and by $0.10 per basic and diluted share in 2012. 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 and continue to gain additional experience with return rates for Makena, 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.
Other Product Sales and Royalties
Other product sales and royalties primarily included Feraheme product sales to Takeda and royalties from Takeda as well as net product sales of MuGard. Prior to the Takeda Termination Agreement, we recorded all product sales of Feraheme sold to Takeda in deferred revenues in our consolidated balance sheet. We recognized these deferred revenues, and the associated cost of product sales, in our consolidated statement of operations at the time Takeda reported to us that sales had been made to its customers. At December 31, 2014, as the result of terminating the Amended Takeda Agreement, we recognized these remaining balances of deferred revenues and associated cost of product sales.
License Fee and Other Collaboration Revenues
The terms of product development and commercialization agreements entered into between us and our collaborative licensees may include non-refundable license fees, payments based on the achievement of certain milestones and performance goals, reimbursement of certain out-of-pocket costs, payment for manufacturing services, and royalties on product sales. We recognize license fee and research and development revenue under collaborative arrangements over the term of the applicable agreements using a proportional performance model, if practical. Otherwise, we recognize such revenue on a straight-line basis. Under this model, revenue is generally recognized in an amount equal to the lesser of the amount due under the agreements or an amount based on the proportional performance to date. In cases where project costs or other performance metrics are not estimable but there is an established contract period, revenues are recognized on a straight-line basis over the term of the relevant agreement. In cases where we are reimbursed for certain research and development costs associated with our collaboration agreements and where we are acting as the principal in carrying out these services, any reimbursement payments are recorded in license fee and other collaboration revenues in our consolidated statement of operations to match the costs that we incur during the period in which we perform those services. Nonrefundable payments and fees are recorded as deferred revenue upon receipt and may require deferral of revenue recognition to future periods.
Multiple Element Arrangements and Milestone Payments
We evaluate revenue from arrangements that have multiple elements to determine whether the components of the arrangement represent separate units of accounting as defined in the accounting guidance related to revenue arrangements with multiple deliverables. Under current accounting guidance, which governs any agreements that contain multiple elements that are either entered into or materially modified subsequent to January 1, 2011, companies are required to establish the fair value of undelivered products and services based on a separate revenue recognition process using management's best estimate of the selling price for an undelivered item when there is no vendor-specific objective evidence or third-party evidence to determine the fair value of that undelivered item. Agreements entered into prior to January 1, 2011, that have not been materially modified are accounted for under previous accounting guidance, which provides that an element of a contract can be accounted for separately if the delivered elements have standalone value and the fair value of all undelivered elements is determinable. If an element is considered to have standalone value but the fair value of any of the undelivered items cannot be determined, all elements of the arrangement are recognized as revenue as a single unit of accounting over the period of performance for such undelivered items or services. Significant management judgment is required in determining what elements constitute deliverables and what deliverables or combination of deliverables should be considered units of accounting.
When multiple deliverables are combined and accounted for as a single unit of accounting, we base our revenue recognition pattern on the last to be delivered element. Revenue is recognized using either a proportional performance or straight-line method, depending on whether we can reasonably estimate the level of effort required to complete our performance obligations under an arrangement and whether such performance obligations are provided on a best-efforts basis. To the extent we cannot reasonably estimate our performance obligations, we recognize revenue on a straight-line basis over the period we expect to complete our performance obligations. Significant management judgment is required in determining the level of effort required under an arrangement and the period over which we are expected to complete our performance obligations under an arrangement. We may have to revise our estimates based on changes in the expected level of effort or the period we expect to complete our performance obligations.
Our collaboration agreements may entitle us to additional payments upon the achievement of performance-based milestones. If a milestone involves substantive effort on our part and its achievement is not considered probable at the inception of the collaboration, we recognize the milestone consideration as revenue in the period in which the milestone is achieved only if it meets the following additional criteria:
•	The milestone consideration received is commensurate with either the level of effort required to achieve the milestone or the enhancement of the value of the item delivered as a result of a specific outcome resulting from our performance to achieve the milestone;
•	The milestone is related solely to our past performance; and
•	The milestone consideration is reasonable relative to all deliverables and payment terms in the arrangement.
There is significant judgment involved in determining whether a milestone meets all of these criteria. For milestones that do not meet the above criteria and are therefore not considered substantive milestones, we recognize that portion of the milestone payment equal to the percentage of the performance period completed at the time the milestone is achieved and the above conditions are met. The remaining portion of the milestone will be recognized over the remaining performance period using a proportional performance or straight-line method.
Amounts received prior to satisfying the above revenue recognition criteria are recorded as deferred revenue in our consolidated balance sheets. Amounts not expected to be recognized within the next 12 months are classified as long-term deferred revenue.
Research and Development Expenses
Research and development expenses include external expenses, such as costs of clinical trials, contract research and development expenses, certain manufacturing research and development costs, regulatory filing fees, consulting and professional fees and expenses, and internal expenses, such as compensation of employees engaged in research and development activities, the manufacture of product needed to support research and development efforts, related costs of facilities, and other general costs related to research and development. Manufacturing costs are generally expensed as incurred until a product has received the necessary initial regulatory approval.
Advertising Costs
Advertising costs are expensed as incurred and are included in selling, general and administrative expenses in our consolidated statements of operations. Advertising costs, including promotional expenses and costs related to trade shows were $2.1 million, $1.9 million and $1.8 million for the years ended December 31, 2014, 2013 and 2012, respectively.
Shipping and Handling Costs
We utilize two third-party logistics providers, both of which are subsidiaries of one of our distribution customers, to provide us with various shipping and handling services related to sales of our products. As we receive an identifiable benefit and we can reasonably estimate the fair value of this benefit, we have recorded $0.3 million, $0.3 million and $0.2 million as a selling, general and administrative expense during 2014, 2013 and 2012, respectively.
Equity-Based Compensation
Under the fair value recognition guidance of equity-based compensation accounting rules, equity-based compensation cost is generally required to be measured at the grant date (based upon an estimate of the fair value of the compensation granted) and recorded to expense over the requisite service period, which generally is the vesting period. Because equity-based compensation expense is based on awards ultimately expected to vest, we must make certain judgments about whether employees and directors will complete the requisite service period. Accordingly, we have reduced the compensation expense being recognized for estimated 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. Forfeitures are estimated based upon historical experience and adjusted for unusual events such as corporate restructurings, which can result in higher than expected turnover and forfeitures. If factors change and we employ different forfeiture rate assumptions in future periods, the compensation expense that we record in the future may differ significantly from what we have recorded in the current period.
We estimate the fair value of equity-based compensation involving stock options based on the Black-Scholes option pricing model. We estimate the fair value of our restricted stock units ("RSUs") whose vesting is contingent upon market conditions using the Monte-Carlo simulation model. These models require the input of several factors such as the expected option term, the expected risk-free interest rate over the expected option term, the expected volatility of our stock price over the expected option term, and the expected dividend yield over the expected option term and are subject to various assumptions. The fair value of awards whose fair values are calculated using the Black-Scholes option pricing model is generally being amortized on a straight-line basis over the requisite service period and is recognized based on the proportionate amount of the requisite service period that has been rendered during each reporting period. The fair value of awards with market conditions is being amortized based upon the estimated derived service period, even if the market condition is never achieved. The fair value of awards with performance conditions is being amortized over the requisite service period if we determine that it is probable that the performance condition will be achieved. We believe our valuation methodologies are appropriate for estimating the fair value of the equity awards we grant to our employees and directors. Our equity award valuations are estimates and thus may not be reflective of actual future results or amounts ultimately realized by recipients of these grants. These amounts, and the amounts applicable to future quarters, are also subject to future quarterly adjustments based upon a variety of factors, which include, but are not limited to, changes in estimated forfeiture rates and the issuance of new equity-based awards. The fair value of service-based RSUs granted to our employees and directors is determined based upon the quoted closing market price per share on the date of grant, adjusted for estimated forfeitures.
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 our deferred tax assets will not be realized.
We account for uncertain tax positions using a "more-likely-than-not" threshold for recognizing and resolving uncertain tax positions. The evaluation of uncertain tax positions is based on factors that include, but are not limited to, changes in tax law, the measurement of tax positions taken or expected to be taken in tax returns, the effective settlement of matters subject to audit, new audit activity and changes in facts or circumstances related to a tax position. We evaluate uncertain tax positions on a quarterly basis and adjust the level of the liability to reflect any subsequent changes in the relevant facts surrounding the uncertain positions. Any changes to these estimates, based on the actual results obtained and/or a change in assumptions, could impact our income tax provision in future periods. Interest and penalty charges, if any, related to unrecognized tax benefits would be classified as a provision for income tax in our consolidated statement of operations.
Concentrations and Significant Customer Information
Financial instruments which potentially subject us to concentrations of credit risk consist principally of cash and cash equivalents, investments, and accounts receivable. As of December 31, 2014, our cash, cash equivalents and investments amounted to approximately $144.2 million. We currently invest our excess cash primarily in corporate debt securities. As of December 31, 2014, we had approximately $77.3 million of our total $119.3 million cash and cash equivalents balance invested in institutional money market funds, of which $60.3 million was invested in a single fund.
Our operations are located solely within the U.S. We are focused principally on developing, manufacturing, and commercializing Makena and 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 2014, 2013 and 2012:
		Years Ended
		December 31,
		2014			2013			2012
AmerisourceBergen Drug Corporation			34%			41%			34%
McKesson Corporation			21%			24%			17%
Cardinal Health, Inc.			15%			16%			12%
Takeda Pharmaceuticals Company Limited			11%			11%			31%
In addition, approximately 26%, 30% and 32% of our Feraheme end-user demand in 2014, 2013 and 2012, respectively, was generated by members of a single GPO with which we have contracted. Revenues from customers outside of the U.S. amounted to approximately 12%, 11% and 32% of our total revenues for 2014, 2013 and 2012, respectively, and were principally related to collaboration revenue recognized in connection with the Amended Takeda Agreement with Takeda, which is headquartered in Japan.
We are currently solely dependent on a single supply chain for Feraheme drug substance and drug product and a single supply chain for Makena drug product. We are exposed to a significant loss of revenue from the sale of Feraheme and Makena if our suppliers and/or manufacturers cannot fulfill demand for any reason.
Comprehensive Income (Loss)
The current accounting guidance related to comprehensive income (loss) requires us to display comprehensive income (loss) and its components as part of our consolidated financial statements. Our comprehensive income (loss) consists of net income (loss) and other comprehensive income (loss). Other comprehensive income (loss) includes changes in equity that are excluded from net income (loss), which for all periods presented in these financial statements related to unrealized holding gains and losses on available-for-sale investments, net of tax.
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 (loss) per common share has been computed by dividing net income (loss) by the diluted number of shares outstanding during the period. Except where the result would be antidilutive to net income (loss), diluted net income (loss) per common share would be computed assuming the impact of the conversion of the $200.0 million of 2.5% convertible senior notes due February 15, 2019 (the "Convertible Notes"), the exercise of outstanding stock options, and the vesting of RSUs.
We have a choice to settle the conversion obligation under the Convertible Notes in cash, shares or any combination of the two. Pursuant to certain covenants in our Term Loan Facility (as defined in Note S, "Debt" below), which we entered into to partially fund the acquisition of Lumara Health, we may be restricted from settling conversion in whole or in part with cash unless certain conditions in the Term Loan Facility are satisfied, including a first lien leverage ratio. Therefore, after November 12, 2014 we utilized the if-converted method, which assumes the conversion of the Convertible Notes and reflects the elimination of the interest expense recorded from November 12, 2014 through December 31, 2014. 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 weighted average of the closing price of our common stock, over a certain number of days pursuant to the terms of the Convertible Notes, to calculate the number of shares issuable under the conversion premium. In addition, 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 S, "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 were as follows (in thousands, except per share data):
		Years Ended December 31,
		2014			2013			2012
Net income (loss)		$	135,817		$	(9,602	)	$	(16,750	)
Weighted average common shares outstanding (basic)			22,416			21,703			21,392
Effect of dilutive securities (in shares):
Stock options and restricted stock units			520			—			—
Convertible 2.5% senior notes			2,289			—			—
Shares used in calculating dilutive net income (loss) per share			25,225			21,703			21,392
Net income (loss) per share:
Basic		$	6.06		$	(0.44	)	$	(0.78	)
Diluted		$	5.45		$	(0.44	)	$	(0.78	)
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 (in thousands):
		Years Ended December 31,
		2014			2013			2012
Options to purchase shares of common stock			2,708			2,820			2,190
Shares of common stock issuable upon the vesting of restricted stock units			322			465			374
Warrants			7,382			—			—
Total			10,412			3,285			2,564
During 2014, the average common stock price was below the exercise price of the warrants.
Reclassifications
Certain amounts in prior periods have been reclassified in order to conform to the current period presentation.

Business_Combinations

Business Combinations	12 Months Ended
	Dec. 31, 2014
Business Combinations
Business Combinations
	C.    BUSINESS COMBINATIONS
	As part of our strategy to expand our portfolio with additional commercial-stage products, in November 2014, we acquired Lumara Health and its product Makena. In addition, 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. and its territories (the "U.S. Territory") for the management of all diseases or conditions of the oropharyngeal cavity, including mucositis.
	Lumara Health
	On the Lumara Acquisition Date, we completed our acquisition of 100% of the equity ownership of Lumara Health, excluding the assets and liabilities of the Women's Health Division and certain other assets and liabilities, pursuant to the Lumara Agreement upon which time Lumara Health became our wholly owned subsidiary. In connection with the acquisition of Lumara Health, we acquired Makena, 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.
	Upon the closing of the Lumara Health acquisition (the "Closing"), we paid approximately $600.0 million in cash (subject to finalization of certain adjustments related to Lumara Health's financial position at the time of closing, including adjustments related to net working capital, net debt and transaction expenses) (the "Cash Consideration") and issued approximately 3.2 million shares of our common stock, par value $0.01, having a value of approximately $112.0 million at the time of the Closing, to the holders of Lumara Health common stock, stock options, and RSUs.
	We have agreed to pay additional merger consideration, up to a maximum of $350.0 million, based on the achievement of certain net sales milestones of Makena for the period from December 1, 2014 through December 19, 2019 as follows:
	•	A one-time payment of $100.0 million payable upon achievement of $300.0 million in aggregate net sales in any consecutive 12-month period commencing in the month following the Lumara Acquisition Date ("the First Milestone"); plus
	•	A one-time payment of $100.0 million payable upon achievement of $400.0 million in aggregate net sales in any consecutive 12-month period commencing in the month following the last month in the First Milestone period (the "Second Milestone"); if the Third Milestone payment (described below) has been or is required to be made prior to achieving the Second Milestone, the Second Milestone payment shall be reduced from $100.0 million to $50.0 million; plus
	•	A one-time payment of $50.0 million payable if aggregate net sales equal or exceed $700.0 million in any consecutive 24-calendar month period (which may include the First Milestone period) (the "Third Milestone"); however, no Third Milestone payment will be made if the Second Milestone payment has been or is required to be made in the full amount of $100.0 million; plus
	•	A one-time payment of $100.0 million payable upon achievement of $500.0 million in aggregate net sales in any consecutive 12-month period commencing in the month following the last month in the Second Milestone period (the "Fourth Milestone"); plus
	•	A one-time payment of $50.0 million payable upon achievement of $200.0 million in aggregate net sales in each of the five consecutive calendar years from and including the 2015 calendar year to the 2019 calendar year (the "Fifth Milestone").
	In the event that the conditions to more than one contingent payment are met in any calendar year, any portion of the total amount of contingent payment due in such calendar year in excess of $100.0 million shall be deferred until the next calendar year in which less than $100.0 million in contingent payments is due.
	The following table summarizes the components of the estimated total purchase price at fair value, subject to adjustment upon finalization of Lumara Health's net working capital, net debt and transaction expenses as of the Lumara Acquisition Date (in thousands):
			Total Acquisition Date
			Fair Value
	Cash consideration		$	600,000
	Fair value of 3.2 million shares of AMAG common stock			111,964
	Fair value of contingent milestone payments			205,000
	Estimated working capital and other adjustments			821
	Purchase price paid at closing			917,785
	Less:
	Due from sellers			(5,119	)
	Cash acquired from Lumara Health			(5,219	)
	Total purchase price		$	907,447
	We financed the $600.0 million upfront cash portion of the acquisition through $327.5 million of net proceeds from borrowings under a new $340.0 million term loan (the "Term Loan Facility"), as discussed in more detail in Note S, "Debt", and $272.5 million of existing cash on hand.
	The fair value of the 3.2 million shares of AMAG common stock was determined based on the closing price of our common stock on the NASDAQ Global Select Market of $34.88 per share on November 11, 2014, the closing price immediately prior to the closing of the transaction.
	The fair value of the contingent milestone payments was determined based on our probability-adjusted discounted cash flows estimated to be realized from the net sales of Makena from December 1, 2014 through December 31, 2019. The cash flows were discounted at a rate of 5%, which we believe is reasonable given the level of certainty of the pay-out.
	The net working capital and other adjustments were estimated to be $0.8 million which we paid at the Closing. Subsequent to the Closing, we estimate that the net working capital and other adjustments will result in a reduction to the cash consideration of approximately $5.1 million. Accordingly, we recorded a $5.1 million receivable in prepaid and other current assets in the consolidated balance sheet at December 31, 2014. The net working capital and other adjustments are subject to change upon finalization of certain adjustments related to Lumara Health's financial position at the time of closing.
	At the Closing, $7.0 million of the Cash Consideration was contributed into an escrow fund to secure any Lumara Health security holders' payment obligations with respect to the working capital, net debt and transaction expenses adjustments, which escrow will be released upon the final determination of the Cash Consideration. Also at the Closing, $35.0 million of the Cash Consideration was contributed to a separate escrow fund (the "Indemnification Escrow") to secure the former Lumara Health security holders' obligations to indemnify us for certain matters, including breaches of representations and warranties, covenants included in the Lumara Agreement, payments made by us to dissenting stockholders, specified tax claims, excess parachute claims, and certain claims related to the Women's Health division of Lumara Health, which was divested by Lumara Health prior to the Closing. The portion of the Indemnification Escrow that has not been reduced by any claims by us and is not subject to any unresolved claims will be released to the former Lumara Health security holders at the earlier of (a) March 15, 2016 and (b) five days after the date on which our audited financial statements for our fiscal year ending December 31, 2015 are filed with the Securities and Exchange Commission.
	We accounted for the acquisition of Lumara Health as a business combination using the acquisition method of accounting. Under the acquisition method of accounting, the total purchase price of an acquisition is allocated to the net tangible and identifiable intangible assets acquired and liabilities assumed based on their estimated fair values as of the date of acquisition. We have made a preliminary allocation of the purchase price to the net tangible and intangible assets acquired and liabilities assumed, based on available information and various assumptions we believe are reasonable, with the remaining purchase price recorded as goodwill. Due to the close proximity of the Lumara Acquisition Date to the fiscal 2014 year-end, we were unable to complete our analysis of fair value.
	The following table summarizes the preliminary fair values assigned to the assets acquired and the liabilities assumed by us at the Lumara Acquisition Date (in thousands):
	Accounts receivable		$	34,918
	Inventories			30,300
	Prepaid and other current assets			3,322
	Deferred income tax assets			94,965
	Property and equipment			60
	Makena marketed product			797,100
	IPR&D			79,100
	Restricted cash			1,997
	Other long-term assets			3,412
	Accounts payable			(3,807	)
	Accrued expenses			(41,532	)
	Deferred income tax liabilities			(293,649	)
	Other long-term liabilities			(4,563	)
	Total estimated identifiable net assets			701,623
	Goodwill			205,824
	Total		$	907,447
	The preliminary values assigned to accounts receivable, prepaid and other current assets, other long-term assets, accounts payable, accrued expenses, deferred income taxes, other long-term liabilities and goodwill presented in the table above are subject to change as additional information becomes available concerning the fair value and tax basis of the assets acquired and liabilities assumed. Any adjustments to the preliminary fair value of these acquired assets and liabilities assumed will be made as soon as practicable but not later than one year from the Lumara Acquisition Date.
	The gross contractual amount of accounts receivable at the Lumara Acquisition Date was $40.5 million. The $30.3 million fair value of inventories included a fair value step-up adjustment of $26.1 million, which will be amortized and recognized as cost of product sales in our consolidated statements of operations as the related inventories are sold. We recognized $1.3 million of the fair value adjustment as cost of product sales during the year ended December 31, 2014. The remaining $24.8 million is estimated to be recognized as follows: $11.1 million in fiscal 2015, $3.5 million in fiscal 2016, $4.0 million in fiscal 2017, $3.5 million in fiscal 2018 and $2.7 million in fiscal 2019.
	The fair value amounts for the Makena marketed product (the "Marketed Product") and IPR&D were determined based on assumptions that market participants would use in pricing an asset, based on the most advantageous market for the assets (i.e., its highest and best use). We determined the fair value of the Marketed Product and the IPR&D using the income approach, which is a valuation technique that provides an estimate of the fair value of an asset based on market participant expectations of the cash flows an asset would generate over its remaining useful life. Some of the more significant assumptions used in the income approach from the perspective of a market participant include the estimated net cash flows for each year for each project or product (including net revenues, cost of product sales, research and development costs, selling and marketing costs and working capital/asset contributory asset charges), the discount rate that measures the risk inherent in each future cash flow stream, the assessment of each asset's life cycle, competitive trends impacting the asset and each cash flow stream as well as other factors, including the major risks and uncertainties associated with the timely and successful completion of the IPR&D projects, such as legal risk and regulatory risk.
	The fair value of the acquired IPR&D asset represents the value assigned to acquired research and development projects that, as of the Lumara Acquisition Date, had not established technological feasibility and had no alternative future use, including certain programs associated with the Makena lifecycle management program to extend the brand franchise beyond the February 2018 exclusivity date, such as new routes of administration, the use of new delivery technologies, as well as reformulation technologies. We believe the fair values assigned to the Marketed Product and IPR&D assets are based upon reasonable estimates and assumptions given available facts and circumstances as of the Lumara Acquisition Date. If these assets are not successful or successfully developed, sales and profitability may be adversely affected in future periods, and as a result, the value of the assets may become impaired.
	The acquisition of Lumara Health is expected to result in carryover basis for all tax attributes. Both AMAG and Lumara Health have deferred tax assets for which full valuation allowances were provided in the pre-acquisition financial statements. However, we have considered certain of the deferred tax liabilities recorded in acquisition accounting as sources of income to support realization of Lumara Health's deferred tax assets at December 31, 2014. Based on the preliminary fair value adjustments primarily related to inventories and identifiable intangible assets acquired, we recorded a net deferred tax liability of $198.7 million in our consolidated balance sheet as of December 31, 2014 using a combined federal and state statutory income tax rate of 38.8%. The net deferred tax liability represents the $293.7 million of deferred tax liabilities recorded in acquisition accounting (primarily related to the fair value adjustments to Lumara Health's inventories and identifiable intangible assets) offset by $95.0 million of deferred tax assets acquired from Lumara Health which we have determined, on a preliminary basis, are 'more likely than not' to be realized. See Note K, "Income Taxes," for additional information.
	These tax estimates are preliminary and subject to change based on, among other things, management's final determination of the fair values of the tangible and identifiable intangible assets acquired and liabilities assumed by jurisdiction, the deductibility of acquisition-related costs and other costs deducted by Lumara pre-acquisition, and management's assessment of the combined company's ability to utilize the future benefits from acquired and legacy deferred tax assets.
	Goodwill is calculated as the difference between the acquisition date fair value of the consideration transferred and the fair values of the net assets acquired and liabilities assumed. The $205.8 million of goodwill resulting from the acquisition was primarily due to the net deferred tax liabilities recorded on the fair value adjustments to Lumara Health's inventories and identifiable intangible assets. The goodwill is not deductible for income tax purposes.
	Acquisition-related costs are not included as a component of consideration transferred and are expensed as incurred. We incurred approximately $9.5 million of acquisition-related costs in 2014 related to the merger with Lumara Health. These costs primarily represented financial advisory fees, legal fees, due diligence and other costs and expenses.
	During the post-acquisition period in fiscal 2014, Lumara Health generated $22.5 million of revenue from sales of Makena. We determined that separate disclosure of Lumara Health's earnings for the post-acquisition period in fiscal 2014 is not practicable due to the integration of Lumara Health's operations into our business upon acquisition.
	The following table presents our revenue and net income (loss) on a pro forma combined basis, assuming that the merger occurred on January 1, 2013 and does not include any expected cost savings or restructuring actions which may be achievable or which may occur subsequent to the acquisition of Lumara Health or the impact of any non-recurring activity. For purposes of preparing the following pro forma information, certain items recorded in 2014, such as the $153.2 million tax benefit and the $9.5 million of acquisition-related costs are reflected in 2013 as if the acquisition occurred on January 1, 2013. In addition, the pro forma combined net income (loss) in fiscal 2013 does not give effect to the elimination of approximately $385.9 million of non-recurring reorganization gains, net of losses and expenses, realized in connection with Lumara Health's exit from bankruptcy in September 2013 as such amounts are not directly related to the acquisition of Lumara Health (in thousands):
			Year Ended
			December 31,
			2014			2013
	Pro forma combined revenues		$	267,705		$	179,561
	Pro forma combined net income (loss)		$	(23,942	)	$	463,522
	This pro forma financial information is not necessarily indicative of our consolidated operating results that would have been reported had the transactions been completed as described herein, nor is such information necessarily indicative of our consolidated results for any future period.
MuGard
MuGard was launched in the U.S. by PlasmaTech Biopharmaceuticals, Inc. (formerly known as Access Pharmaceuticals, Inc. ("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.
PlasmaTech remains responsible for the manufacture of MuGard and we have entered into a quality agreement and a supply agreement with PlasmaTech under which we purchase MuGard inventory from PlasmaTech. Our inventory purchases are at the price actually paid by PlasmaTech to purchase it from a third-party plus a mark-up to cover administration, handling and overhead.
In consideration for the license, we paid PlasmaTech an upfront payment of $3.3 million on June 6, 2013 (the "MuGard License Date"). We are required to pay royalties to PlasmaTech on future 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 consolidated balance sheet as of the MuGard License Date.
We did not assume any pre-existing liabilities related to the MuGard business, contingent or otherwise, arising prior to the MuGard License Date. We are accounting for the acquisition of the MuGard Rights as a business combination under the acquisition method of accounting since we acquired the U.S. commercial rights for MuGard and inventory, and obtained access to certain related regulatory assets and product supply, employees and other assets, including certain patent and trademark rights, contracts, and related books and records, held by PlasmaTech which are exclusively related to MuGard (inputs), including the infrastructure to sell, distribute and market MuGard (processes) and net sales of MuGard (outputs). In addition, during the term of the MuGard License Agreement, we will have control over sales, distribution and marketing of MuGard in the U.S. as PlasmaTech has assigned to us all of its right, title and interest in MuGard-related internet and social media outlets and other sales, marketing and promotional materials currently owned or controlled by PlasmaTech. PlasmaTech will no longer commercialize, market, promote, sell or make public communications relating to MuGard in the U.S Territory, except as may be agreed to by us. PlasmaTech has also agreed to not, directly or indirectly, research, develop, market, sell or commercialize any medical devices that directly compete with MuGard for the treatment of any diseases or conditions of the oropharyngeal cavity in the U.S. Territory.
We estimated the fair value of the acquired MuGard Rights using the income approach, which is a valuation technique to convert future amounts to a single present amount (discounted) and is described above.
The following table summarizes the total consideration for the MuGard Rights (in thousands):
		Total
		Acquisition
		Date Fair
		Value
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 MuGard License Date. During 2013, we completed the valuation for the acquisition of the MuGard Rights and determined the fair value of the contingent consideration to be $13.7 million as of the MuGard License Date, and the fair value of the intangible asset was determined to be $16.9 million as of the MuGard License Date. The acquisition date fair value of the contingent consideration was determined based on various market factors, including an analysis of estimated sales using a discount rate of approximately 15%. As of December 31, 2014, we estimated 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, which is our best estimate of the period over which we expect the majority of the asset's cash flows to be derived.
The following table summarizes the fair values of the assets acquired related to the business combination as of the MuGard License Date (in thousands):
Assets Acquired:
MuGard intangible asset		$	16,893
Inventory			241
Net identifiable assets acquired		$	17,134
The acquisition date fair value of the intangible asset was determined based on various market factors, including an analysis of estimated sales using a discount rate of 19%. This measure is based on significant Level 3 inputs not observable in the market. Such valuations require significant estimates and assumptions including but not limited to: estimating future cash flows from product sales and developing appropriate discount and probability rates. We believe the estimated fair values of the MuGard Rights are based on reasonable assumptions, however, we cannot provide assurance that the underlying assumptions used to forecast the cash flows will materialize as we estimated and thus, our actual results may vary significantly from the estimated results.
Acquisition-related costs are not included as a component of consideration transferred and are expensed as incurred. We incurred approximately $0.8 million of acquisition-related costs in 2013, which were primarily related to professional and legal fees.
Pro forma results of operations would not be materially different as a result of the acquisition of the MuGard Rights and therefore are not presented.

Investments

Investments	12 Months Ended
	Dec. 31, 2014
Investments
Investments
	D.    INVESTMENTS
	As of December 31, 2014 and 2013, our investments equaled $24.9 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 December 31, 2014 and 2013 (in thousands):
		December 31, 2014
		Amortized		Gross		Gross			Estimated
		Cost		Unrealized		Unrealized			Fair
				Gains		Losses			Value
	Corporate debt securities
	Due in one year or less	$	11,656	$	3	$	(4	)	$	11,655
	Due in one to three years		13,258		10		(33	)		13,235
	Total investments	$	24,914	$	13	$	(37	)	$	24,890
		December 31, 2013
		Amortized		Gross		Gross			Estimated
		Cost		Unrealized		Unrealized			Fair
				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
	During the year ended December 31, 2014, we liquidated $170.4 million of our investments in order to partially fund the acquisition of Lumara Health in November 2014.
	Impairments and Unrealized Gains and Losses on Investments
	We did not recognize any other-than-temporary impairment losses in our consolidated statements of operations related to our securities during either 2014, 2013 or 2012. We considered various factors, including 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 December 31, 2014, none 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. Net realized gains were $0.1 million during 2014 and insignificant during 2013. During 2012, we recorded realized losses of $1.5 million to our consolidated statement of operations related to the sale of our then-remaining auction rate securities portfolio.

Fair_Value_Measurements

Fair Value Measurements	12 Months Ended
	Dec. 31, 2014
Fair Value Measurements
Fair Value Measurements
	E.    FAIR VALUE MEASUREMENTS
	The following tables represent the fair value hierarchy as of December 31, 2014 and 2013, for those assets and liabilities that we measure at fair value on a recurring basis (in thousands):
		Fair Value Measurements at December 31, 2014 Using:
		Total			Quoted Prices in		Significant Other		Significant
					Active Markets for		Observable Inputs		Unobservable
					Identical Assets		(Level 2)		Inputs
					(Level 1)				(Level 3)
	Assets:
	Money market funds	$	77,254		$	77,254	$	—	$	—
	Corporate debt securities		24,890			—		24,890		—
	Total Assets	$	102,144		$	77,254	$	24,890	$	—
	Liabilities:
	Contingent consideration—Lumara Health	$	206,600		$	—	$	—	$	206,600
	Contingent consideration—MuGard		12,102			—		—		12,102
	Total Liabilities	$	218,702		$	—	$	—	$	218,702
		Fair Value Measurements at December 31, 2013 Using:
		Total			Quoted Prices in		Significant Other		Significant
					Active Markets for		Observable Inputs		Unobservable
					Identical Assets		(Level 2)		Inputs
					(Level 1)				(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:
	Contingent consideration—MuGard	$	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 either December 31, 2014 or 2013. In addition, there were no transfers or reclassifications of any securities between Level 1 and Level 2 during either 2014 or 2013.
	Contingent consideration
	We accounted for the acquisitions of Lumara Health and the MuGard Rights as business combinations under the acquisition method of accounting. Additional details regarding the Lumara Health acquisition and the MuGard License Agreement can be found in Note C, "Business Combinations." The fair value measurements of contingent consideration obligations and the related intangible assets arising from business combinations are determined using unobservable ("Level 3") inputs. 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 (decreases) in any of those inputs in isolation could result in a significantly lower or higher fair value measurement.
	Lumara Health
	The following table presents a reconciliation of contingent consideration obligations related to the acquisition of Lumara Health measured on a recurring basis using Level 3 inputs as of December 31, 2014 (in thousands):
	Balance as of November 12, 2014	$	—
	Acquisition date fair value of contingent consideration		205,000
	Adjustments to fair value of contingent consideration		1,600
	Balance as of December 31, 2014	$	206,600
	The $1.6 million increase of the contingent consideration related to Lumara Health was due to the time value of money. This adjustment to our contingent consideration liability is included in selling, general and administrative expenses in our consolidated statements of operations. We have classified all of the Lumara Health contingent consideration as a long-term liability in our consolidated balance sheet as of December 31, 2014.
	MuGard
	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 December 31, 2014 and 2013 (in thousands):
	Balance as of June 6, 2013	$	—
	Acquisition date fair value of contingent consideration		13,700
	Payments made		(51	)
	Adjustments to fair value of contingent consideration		1,074
	Other adjustments		(173	)
	Balance as of December 31, 2013	$	14,550
	Payments made		(270	)
	Adjustments to fair value of contingent consideration		(2,281	)
	Other adjustments		103
	Balance as of December 31, 2014	$	12,102
	During 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 $2.3 million for year ended December 31, 2014. During the year ended December 31, 2013, we increased our MuGard related contingent consideration liability by $1.1 million. These adjustments to contingent consideration liability are included in selling, general and administrative expenses in our consolidated statements of operations.
	As of December 31, 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 MuGard License 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 $0.8 million of the MuGard contingent consideration as a short-term liability, which was included in accrued expenses in our consolidated balance sheet as of December 31, 2014.
	In addition, in connection with the acquisition of the MuGard Rights, we acquired an intangible asset of $16.9 million, which was originally determined based on fair value measurements. These measures were based on significant Level 3 inputs not observable in the market. Key assumptions include a discount rate of 19%. We believe the estimated fair values of the MuGard Rights are based on reasonable assumptions, however, we cannot provide assurance that the underlying assumptions used to forecast the cash flows will materialize as we estimated and thus, our actual results may vary significantly from the estimated results.
	Debt
	In February 2014, we issued the Convertible Notes. As of December 31, 2014, the fair value of our Convertible Notes was $332.0 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 November 2014, in connection with the acquisition of Lumara Health, we entered into the Term Loan Facility. The fair value of our outstanding borrowings under the Term Loan Facility was approximately $342.0 million at December 31, 2014, which differs from their carrying values. The fair value of our Term Loan debt is influenced by interest rates and are Level 2 inputs.
	See Note S, "Debt," for additional information on our debt obligations.

Accounts_Receivable_Net

Accounts Receivable, Net	12 Months Ended
	Dec. 31, 2014
Accounts Receivable, Net
Accounts Receivable, Net
	F.     ACCOUNTS RECEIVABLE, NET
	Our net accounts receivable were $38.2 million and $6.8 million as of December 31, 2014 and 2013, respectively, and primarily represented amounts due from wholesalers, distributors and specialty pharmacies to whom we sell our products directly. The increase in accounts receivable in 2014 is due primarily to the inclusion of Lumara Health. Accounts receivable are recorded net of reserves for estimated chargeback obligations, prompt payment discounts and any allowance for doubtful accounts.
	As part of our credit management policy, we perform ongoing credit evaluations of our customers, and we have not required collateral from any customer. To date, we have not experienced significant bad debts. Accordingly, we have not established an allowance for doubtful accounts at either December 31, 2014 or 2013. If the financial condition of any of our significant customers was to deteriorate and result in an impairment of its ability to make payments owed to us, an allowance for doubtful accounts may be required which could have a material effect on earnings in the period of any such adjustment.
	Customers which represented greater than 10% of our accounts receivable balances as of December 31, 2014 and 2013 were as follows:
		December 31,
		2014		2013
	AmerisourceBergen Drug Corporation		45%		43%
	McKesson Corporation		12%		29%
	Cardinal Health, Inc.		<10%		19%

Inventories

Inventories	12 Months Ended
	Dec. 31, 2014
Inventories
Inventories
	G.    INVENTORIES
	Our major classes of inventories were as follows as of December 31, 2014 and 2013 (in thousands):
		December 31,
		2014		2013
	Raw materials	$	14,188	$	3,157
	Work in process		5,965		8,322
	Finished goods		20,457		5,738
	Total		40,610		17,217
	Included in other long-term assets:
	Raw materials		7,798		—
	Total inventories	$	48,408	$	17,217
	During 2014 and 2013, we expensed $0.7 million and $1.1 million of Feraheme commercial inventory, respectively, which we determined would be solely used in development activities at our third-party suppliers and which we recorded in research and development expenses. In addition, during 2014 and 2013, we expensed $0.6 million and $1.1 million of Feraheme commercial inventory deemed no longer saleable, which we recorded in cost of product sales.
	The increase in total raw materials and finished goods for the year ended December 31, 2014 is primarily due to the inclusion of Makena inventory acquired in connection with the merger with Lumara Health. We recorded the acquired Makena inventory at fair value, which required a step-up adjustment to recognize the inventory at its expected net realizable value. The $30.3 million fair value of Makena inventories included a fair value step-up adjustment of $26.1 million, which will be amortized and recognized as cost of product sales in our consolidated statements of operations as the related inventories are sold. We recognized $1.3 million of the fair value adjustment as cost of product sales during the year ended December 31, 2014. The remaining $24.8 million is estimated to be recognized as follows: $11.1 million in fiscal 2015, $3.5 million in fiscal 2016, $4.0 million in fiscal 2017, $3.5 million in fiscal 2018 and $2.7 million in fiscal 2019. In connection with the fair value step-up adjustment of Makena inventory, we have recorded a portion of the associated raw material inventory and associated step-up adjustment in other long-term assets as we believe that the amount of inventory purchased in the acquisition exceeds our normal inventory cycle. See Note C, "Business Combinations," for additional information.

Property_and_Equipment_Net

Property and Equipment, Net	12 Months Ended
	Dec. 31, 2014
Property and Equipment, Net
Property and Equipment, Net
	H.    PROPERTY AND EQUIPMENT, NET
	Property and equipment consisted of the following as of December 31, 2014 and 2013 respectively (in thousands):
		December 31,
		2014			2013
	Furniture and fixtures	$	1,574		$	1,536
	Leasehold improvements		430			430
	Laboratory and production equipment		493			376
			2,497			2,342
	Less—accumulated depreciation		(978	)		(496	)
	Property and equipment, net	$	1,519		$	1,846
	In September 2013, we relocated our corporate offices from Lexington, Massachusetts to Waltham, Massachusetts and recorded $1.6 million of new leasehold improvements and furniture and fixtures related to our new location.
	During 2014, 2013 and 2012, we incurred $0.5 million, $3.0 million and $4.2 million of depreciation expense, respectively. The $3.0 million of depreciation expense in 2013 included $1.9 million of accelerated depreciation expense related to fixed assets at our prior office facility. The $4.2 million of depreciation expense in 2012 included $1.4 million of accelerated depreciation related to our former Cambridge, Massachusetts manufacturing facility and related assets and a $1.1 million impairment loss to decrease the carrying value of these assets to our best estimate of fair value.

Goodwill_and_Intangible_Assets

Goodwill and Intangible Assets, Net	12 Months Ended
	Dec. 31, 2014
Goodwill and Intangible Assets, Net
Goodwill and Intangible Assets, Net
	I.     GOODWILL AND INTANGIBLE ASSETS, NET
	Goodwill
	In connection with our November 2014 acquisition of Lumara Health, we recognized $205.8 million of goodwill as of December 31, 2014. See Note C, "Business Combinations," for additional information. There has been no change in the goodwill balance since the acquisition.
	Intangible Assets, Net
	Our identifiable intangible assets consist of license agreements, product rights and other identifiable intangible assets, which result from product and business acquisitions. As of December 31, 2014 and 2013, our identifiable intangible assets consisted of the following (in thousands):
		December 31, 2014						December 31, 2013
		Cost		Accumulated		Net		Cost		Accumulated		Net
				Amortization						Amortization
	Amortizable intangible assets:
	Makena Marketed Product	$	797,100	$	4,834	$	792,266	$	—	$	—	$	—
	MuGard Rights		16,893		351		16,542		16,893		49		16,844
			813,993		5,185		808,808		16,893		49		16,844
	Indefinite-lived intangible assets:
	IPR&D		79,100		—		79,100		—		—		—
	Total intangible assets	$	893,093	$	5,185	$	887,908	$	16,893	$	49	$	16,844
	The Marketed Product and IPR&D intangible assets were acquired in connection with our acquisition of Lumara Health in November 2014. Amortization of the Marketed Product asset is being recognized using an economic consumption model over twenty years, which we believe is an appropriate amortization period due to the estimated economic lives of the product rights and related intangibles. See Note C, "Business Combinations," for additional information.
	The MuGard Rights were acquired from PlasmaTech in June 2013. Amortization of the MuGard Rights is being recognized using an economic consumption model over ten years, 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. See Note C, "Business Combinations," for additional information.
	We recorded $5.1 million, less than $0.1 million and no amortization expense for the years ended December 31, 2014, 2013 and 2012, respectively. Amortization expense is recorded in cost of product sales in our consolidated statements of operations. We expect amortization expense related to our finite-lived intangible assets for the next five fiscal years to be as follows (in thousands):
	Period	Estimated
		Amortization
		Expense
	Year Ended December 31, 2015		51,886
	Year Ended December 31, 2016		64,977
	Year Ended December 31, 2017		76,679
	Year Ended December 31, 2018		84,359
	Year Ended December 31, 2019		55,746
	Total	$	333,647

Current_and_Long_Term_Liabilit

Current and Long- Term Liabilities	12 Months Ended
	Dec. 31, 2014
Current and Long-Term Liabilities
Current and Long-Term Liabilities
	J.     CURRENT AND LONG-TERM LIABILITIES
	Accrued Expenses
	Accrued expenses consisted of the following as of December 31, 2014 and 2013 (in thousands):
			December 31,
			2014		2013
	Commercial rebates, fees and returns		$	44,807	$	4,839
	Professional, license, and other fees and expenses			14,888		1,932
	Salaries, bonuses, and other compensation			10,176		5,419
	Clinical, manufacturing and regulatory consulting fees and expenses			7,181		7,834
	Restructuring expense			1,952		—
	Commercial consulting fees and expenses			1,089		1,301
	Short-term contingent consideration			718		941
	Total accrued expenses		$	80,811	$	22,266
	Deferred Revenues
	Deferred revenues consisted of the following as of December 31, 2014 and 2013 (in thousands):
			December 31,
			2014		2013
	Short-term deferred revenues:
	Takeda		$	44,376	$	8,226
	Total		$	44,376	$	8,226
	Long-term deferred revenues:
	Takeda		$	—	$	43,534
	3SBio			—		1,000
	Total		$	—	$	44,534
	Our deferred revenues related to Takeda were recorded in our consolidated balance sheets and include the following as of December 31, 2014:
	•	$41.2 million related to the amortization of upfront payments and milestone payments recognized under the Amended Takeda Agreement. Included in the $41.2 million was the amortization of upfront payments we received from Takeda in 2010, which we were recognizing on a straight-line basis over a period of 10 years, which represented the then current patent life of Feraheme and our best estimate of the period over which we were to substantially perform our obligations. In addition, included in the $41.2 million was the amortization of an aggregate of $18.0 million in milestone payments we received from Takeda in 2012 associated with the commercial launches of Feraheme in the EU and Canada, which we were amortizing over the original life of the Takeda Agreement. During 2014 and 2013, we recorded $8.2 million and $7.9 million to license fee and other collaboration revenues in our consolidated statements of operations, including, as a result of the Takeda Termination Agreement, the accelerated recognition of $0.3 million of the remaining deferred revenue associated with upfront and milestone payments received to date from Takeda and previously deferred; and
	•	$3.2 million related to certain agreed upon costs under the terms of the Takeda Termination Agreement.
	We expect to recognize the remaining balance of the deferred revenue related to Takeda within the next 12 months. Further, as of December 31, 2014, we recognized the $2.5 million remaining balance of previously deferred product sales to Takeda and the related cost of product sales. See Note R, "Collaborative Agreements," for further information.
	In consideration of the grant of the license to 3SBio Inc. ("3SBio") in 2008, we received an upfront payment of $1.0 million, the recognition of which had been deferred. 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, at which time we recognized the $1.0 million to income in our consolidated statement of operations.
	Other Long-Term Liabilities
	Other long-term liabilities at December 31, 2014 consisted of deferred rent related to the lease of our principal executive offices in Lexington, Massachusetts and after September 2013, Waltham, Massachusetts, as well as our lease obligations assumed under the lease of Lumara Health's former principal executive offices in St. Louis, Missouri. In addition, other long-term liabilities include future payments to be made to certain states in compliance with a 2011 Lumara Health Settlement Agreement with the Department of Justice, which resolved certain claims under the qui tam provisions of the False Claims Act. Other long-term liabilities at December 31, 2013 consisted solely of deferred rent related to the lease of our principal executive offices.

Income_Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2014
Income Taxes
Income Taxes
	K.    INCOME TAXES
	The income tax benefit consisted of the following (in thousands):
		Years Ended December 31,
		2014			2013			2012
	Current:
	Federal	$	—		$	—		$	—
	State		—			—			—
	Total current	$	—		$	—		$	—
	Deferred:
	Federal	$	(142,884	)	$	—		$	(833	)
	State		(10,275	)		—			(21	)
	Total deferred	$	(153,159	)	$	—		$	(854	)
	Total income tax benefit	$	(153,159	)	$	—		$	(854	)
	The reconciliation of the statutory U.S. federal income tax rate to our effective income tax rate is as follows:
		Years Ended December 31,
		2014			2013			2012
	Statutory U.S. federal tax rate		-34.00%			-34.00%			-34.00%
	State taxes, net of federal benefit		-7.90%			2.4%			4.2%
	Equity-based compensation expense		10.6%			9.4%			42.4%
	Permanent items, net		16.0%			5.3%			1.2%
	Tax credits		-3.00%			0.5%			0.8%
	Valuation allowance		-864.90%			16.4%			-19.50%
	Total tax benefit		-883.20%			0.0%			-4.90%
	For the year ended December 31, 2014, we recognized an income tax benefit of $153.2 million, representing an effective tax rate of (883.2%). The difference between the statutory tax rate and the effective tax rate was attributable to a non-recurring benefit of $153.2 million for the release of a portion of the valuation allowance due to taxable temporary differences available as a source of income to realize the benefit of certain pre-existing AMAG deferred tax assets as a result of the Lumara Health acquisition. Excluding the impact of this item, our overall tax provision and effective tax rate would have been zero. Other factors resulting in a difference between the statutory tax rate and the effective tax rate included certain non-deductible stock compensation expenses, certain non-deductible expenses for tax purposes and tax credits. See Note C, "Business Combinations," for more information on the Lumara Health acquisition.
	We did not recognize any current federal or state income tax benefit for the year ended December 31, 2013 as we were subject to a full valuation allowance. For the year ended December 31, 2012, we recognized a $0.9 million deferred tax benefit, as the result of the recognition of corresponding income tax expense associated with the decrease in the unrealized loss on our investments, primarily related to auction rate securities, which we carried at fair market value during 2012. The corresponding income tax expense was recorded in other comprehensive loss.
	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. The components of our deferred tax assets and liabilities are as follows (in thousands):
		December 31,
		2014			2013
	Assets
	Net operating loss carryforwards	$	188,873		$	85,269
	Tax credit carryforwards		24,574			12,396
	Deferred revenue		17,216			20,368
	Equity-based compensation expense		3,436			4,176
	Capitalized research & development		32,359			39,214
	Intangibles		272			680
	Debt instruments		731			—
	Reserves		7,782			—
	Property, plant and equipment		61			—
	Other		5,014			4,371
	Liabilities
	Property, Plant, and Equipment Depreciation		—			(58	)
	Intangible Assets and Inventory Amortization		(290,491	)		—
	Other		(1,795	)		—
			(11,968	)		166,416
	Valuation allowance		(33,557	)		(166,416	)
	Net deferred taxes	$	(45,525	)	$	—
	The valuation allowance decreased by approximately $132.9 million for the year ended December 31, 2014 primarily due to taxable temporary differences available as a source of income to realize the benefit of certain pre-existing AMAG deferred tax assets as a result of the Lumara Health acquisition, which provided a tax benefit of $153.2 million offset by an increase in the valuation allowance of $20.3 million primarily related to certain Lumara deferred tax assets established in purchase accounting. In determining the amount of valuation allowance release, we considered the relevant tax law ordering rules for utilization of tax assets to determine whether the acquired Lumara Health or the pre-existing AMAG deferred tax assets were realizable. As of December 31, 2014, we maintained a partial valuation allowance on the net deferred tax assets as we benefitted only those deferred tax assets to the extent that existing taxable temporary differences could be used as a source of future income.
	At December 31, 2014, we had federal net operating loss ("NOL") carryforwards of approximately $542.3 million and state NOL carryforwards of up to $242.2 million of which $254.1 million and $124.7 million were acquired as part of the Lumara Health transaction. We also had federal capital loss carryforwards of $2.1 million to offset future capital gains. At December 31, 2014, $30.6 million and $5.4 million of federal and state NOLs, respectively, related to excess equity-based compensation tax deductions the benefits for which will be recorded to additional paid-in capital when recognized through a reduction of cash taxes paid. The federal NOLs and the most significant state NOLs expire at various dates through 2034. The capital loss carryforwards will expire through 2017. We have federal tax credits of approximately $21.6 million, to offset future tax liabilities of which $12.0 million were acquired as part of the Lumara Health transaction. We have state tax credits of $4.5 million to offset future tax liabilities. These federal and state tax credits will expire periodically through 2034 if not utilized.
	Utilization of our NOLs and research and development ("R&D") credit carryforwards may be subject to a substantial annual limitation due to ownership change limitations that have occurred previously or that could occur in the future in accordance with Section 382 of the Internal Revenue Code of 1986 ("Section 382") as well as similar state provisions. These ownership changes may limit the amount of NOL and R&D credit carryforwards that can be utilized annually to offset future taxable income and taxes, respectively. In general, an ownership change as defined by Section 382 results from transactions increasing the ownership of certain shareholders or public groups in the stock of a corporation by more than 50 percentage points over a three-year period. Since our formation, we have raised capital through the issuance of capital stock on several occasions. These financings, combined with the purchasing shareholders' subsequent disposition of those shares, may have resulted in a change of control as defined by Section 382 or could result in a change of control in the future upon subsequent disposition. We conducted an analysis under Section 382 to determine if historical changes in ownership through December 31, 2012 would limit or otherwise restrict our ability to utilize these NOL and R&D credit carryforwards. As a result of this analysis, we do not believe there are any significant limitations on our ability to utilize these carryforwards. However, future changes in ownership after December 31, 2012 could affect the limitation in future years. Any limitation may result in expiration of a portion of the NOL or R&D credit carryforwards before utilization.
	At December 31, 2014 and 2013, we had no unrecognized tax benefits. We have not, as yet, conducted a study of our R&D credit carryforwards. Such a study could result in an adjustment to our R&D credit carryforwards; however, until a study is completed and any adjustment is known, no amounts are being presented as an uncertain tax position.
	We would recognize both accrued interest and penalties related to unrecognized benefits in income tax expense. We have not recorded any interest or penalties on any unrecognized benefits since inception.
	The statute of limitations for assessment by the Internal Revenue Service (the "IRS") and state tax authorities is closed for tax years prior to December 31, 2011, although carryforward attributes that were generated prior to tax year 2011 may still be adjusted upon examination by the IRS or state tax authorities if they either have been or will be used in a future period. We file income tax returns in the U.S. federal and various state jurisdictions. There are currently no federal or state audits in progress.
	It should be noted that the allocation of the purchase price related to the Lumara Health transaction is subject to adjustment upon finalization of fair valuation procedures and therefore the impact of the tax benefit associated with the valuation allowance release and deferred tax assets and liabilities (including uncertain tax positions) are subject to change.

Accumulated_Other_Comprehensiv

Accumulated Other Comprehensive Income (Loss)	12 Months Ended
	Dec. 31, 2014
Accumulated Other Comprehensive Loss
Accumulated Other Comprehensive Income (Loss)
	L.    ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS)
	The table below presents information about the effects of net income (loss) of significant amounts reclassified out of accumulated other comprehensive loss ("AOCI"), net of tax, during 2014 and 2013 (in thousands):
		December 31,
		2014			2013
	Beginning Balance	$	(3,491	)	$	(3,247	)
	Other comprehensive income (loss) before reclassifications		(191	)		(268	)
	Gain (loss) reclassified from other accumulated comprehensive loss		65			24
	Ending Balance	$	(3,617	)	$	(3,491	)
	The amounts reclassified from other comprehensive loss for 2014 and 2013 primarily represented realized gains on investments, which are included in our consolidated statement of operations under "Gains (losses) on investments, net."

EquityBased_Compensation

Equity-Based Compensation	12 Months Ended
	Dec. 31, 2014
Equity-Based Compensation
Equity-Based Compensation
	M.   EQUITY-BASED COMPENSATION
	We currently maintain three equity compensation plans, including our Third Amended and Restated 2007 Equity Incentive Plan (the "2007 Plan"), our Amended and Restated 2000 Stock Plan (the "2000 Plan") (under which we no longer grant awards) and the Lumara Health Inc. Amended and Restated 2013 Incentive Compensation Plan (the "Lumara Health 2013 Plan"). During 2014, 2013 and 2012, we also granted equity through inducement grants outside of these plans to certain newly hired executive officers and certain employees, including in connection with the Lumara Health acquisition.
	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. In addition, the amendment approved by our stockholders in May 2009 replaced a limitation on the number of shares in the aggregate which could be issued under the 2007 Plan with respect to RSUs, restricted stock, stock and similar equity interests in our company with a fungible share reserve whereby the number of shares available for issuance under the 2007 Plan is reduced by one share of our common stock issued pursuant to an option or stock appreciation right and by 1.5 shares for each share of our common stock issued pursuant to a RSU award or other similar equity-based award.
	The 2007 Plan provides for the grant of stock options, RSUs, restricted stock, stock, and other equity interests in our company to employees, officers, directors, consultants, and advisors of our company and our subsidiaries. We generally issue common stock from previously authorized but unissued shares to satisfy option exercises and restricted stock awards. The terms and conditions of each such grant, including, but not limited to, the number of shares, the exercise price, term of the option/award and vesting requirements, are determined by our Board of Directors (the "Board") or the Compensation Committee of our Board. Our Board may award stock options in the form of nonqualified stock options or incentive stock options ("ISOs"). Stock options may be granted at an exercise price no less than fair market value of a share of our common stock on the date of grant, as determined by our Board or the Compensation Committee of our Board, subject to certain limitations.
	As of December 31, 2014, we have granted options and RSUs covering 7,414,752 shares of common stock under our 2007 Plan, of which 3,112,356 stock options and 703,124 RSUs have expired or terminated, and of which 610,297 options have been exercised and 577,132 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 December 31, 2014, was 2,051,017 and 360,826, respectively. The remaining number of shares available for future grants as of December 31, 2014 was 1,707,989, 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. The terms and conditions of each such grant, including, but not limited to, the number of shares, the exercise price, term of the option/award and vesting requirements, were determined by our Board or the Compensation Committee of our Board. As of December 31, 2014, we have granted stock options and RSUs covering 2,182,700 shares of common stock under the 2000 Plan, of which 1,049,339 stock options and 1,500 RSUs have expired or terminated, and of which 1,054,095 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 December 31, 2014, was 35,266. There were no remaining RSUs which were issued pursuant to our 2000 Plan as of December 31, 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.
	Lumara Health Inc. Amended and Restated 2013 Incentive Compensation Plan
	On November 12, 2014, we assumed the Lumara Health 2013 Plan in connection with the acquisition of Lumara Health. The total number of shares issuable pursuant to awards under this plan as of the effective date of the acquisition and after taking into account any adjustments as a result of the acquisition, was 200,000 shares.
	The Lumara Health 2013 Plan provides for the grant of stock options, RSUs, restricted stock, stock, stock appreciation rights and other equity interests in our company to certain of our employees, officers, directors, consultants, and advisors of our company and our subsidiaries that are newly-hired or that previously performed services for Lumara Health. We generally issue common stock from previously authorized but unissued shares to satisfy option exercises and restricted stock awards. The terms and conditions of each award assumed in the acquisition of Lumara Health were previously determined by Lumara Health prior to being assumed in connection with the acquisition, subject to applicable adjustments made in connection with such acquisition. The terms and conditions of each award made after the acquisition of Lumara Health, including, but not limited to, the number of shares, the exercise price, term of the option/award and vesting requirements, are determined by our Board or the Compensation Committee of our Board. Our Board may award stock options in the form of nonqualified stock options or ISOs. Stock options may be granted at an exercise price no less than fair market value of a share of our common stock on the date of grant, as determined by our Board or the Compensation Committee of our Board, subject to certain limitations.
	As of December 31, 2014, we have granted new options and RSUs covering 64,000 shares of common stock under the Lumara Health 2013 Plan. The number of options and RSUs outstanding under this plan as of December 31, 2014, was 44,000 and 20,000, respectively. The remaining number of shares available for future grants as of December 31, 2014 was 136,000. All outstanding stock options granted under the Lumara Health 2013 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.
	Other Equity Compensation Grants
	In August 2014, we granted certain members of our senior management performance-based RSUs under our 2007 Plan 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. We recognized $0.1 million of expense related to these awards during December 31, 2014.
	In February 2013, we granted RSUs under our 2007 Plan to certain members of our senior management covering a maximum of 82,500 shares of common stock, which are subject to a performance condition tied to the price of our common stock. These RSUs vest, if at all, at the end of the three-year period ending December 31, 2015 based on the achievement of a minimum, target or maximum stock price range. In the event that the minimum stock price range is not achieved at the measurement date, none of the RSUs will vest. The maximum total fair value of these RSUs is $0.7 million, which is being recognized to expense over a period of three years from the date of grant, net of any estimated and actual forfeitures.
	During 2014, 2013 and 2012, our Board granted options to purchase 165,000, 270,000 and 300,000 shares of our common stock, respectively, and 87,900, 115,000 and 100,000 RSUs, respectively, to certain new-hire employees, including members of our senior management, to induce them to accept employment with us. In addition to these inducement grants, during December 2014, we issued options covering 304,600 shares of our common stock and 22,600 RSUs to certain employees of Lumara Health in order to induce them to accept employment with us following our acquisition of Lumara Health. 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 and the Lumara Health 2013 Plan as permitted under the NASDAQ Stock Market listing 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.
	Since we first began issuing inducement grants outside of our plans in 2012 as permitted under the NASDAQ Stock Market listing rules, we have issued a total of 1,344,000 shares of common stock pursuant to inducement grants, of which 146,250 stock options and 67,500 RSUs have been expired or terminated and of which 28,750 options have been exercised and 75,000 shares of common stock have been issued pursuant to RSUs that became fully vested.
	Equity-based compensation expense
	Equity-based compensation expense for 2014, 2013 and 2012 consisted of the following (in thousands):
		Years Ended December 31,
		2014			2013		2012
	Cost of product sales	$	122		$	121	$	225
	Research and development		1,596			2,149		1,994
	Selling, general and administrative		6,907			5,734		4,805
	Total equity-based compensation expense	$	8,625		$	8,004	$	7,024
	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.
	Due to the uncertainty surrounding the realization of the favorable tax attributes in future tax returns associated with operating losses we incurred in the past, we have not recognized any excess tax benefits from the exercise of options. Accordingly, there was no impact recorded in cash flows from financing activities or cash flows from operating activities as reported in the accompanying consolidated statements of cash flows.
	The following table summarizes the weighted average assumptions we utilized for purposes of valuing grants of options to our employees and non-employee directors:
		Years Ended December 31,
		2014					2013				2012
		Employees			Non-Employee		Employees		Non-Employee		Employees		Non-Employee
					Directors				Directors				Directors
	Risk free interest rate (%)		1.56			1.28		0.95		0.85		0.66		0.68
	Expected volatility (%)		47			46		59		46		57		56
	Expected option term (years)		5.00			4.00		5.00		4.00		4.66		4.00
	Dividend yield		none			none		none		none		none		none
	Risk free interest rates utilized are based upon published U.S. Treasury yields at the date of the grant for the expected option term. During 2014 and 2013, we estimated our expected stock price volatility by basing it on the historical volatility of our own common stock price over the prior period equivalent to our expected option term to better reflect expected future volatility. During 2012, we estimated our expected stock price volatility by basing it on a blend of our own common stock price and the historical volatility of other similar companies over the prior period equivalent to our expected option term to better reflect expected future volatility. To compute the expected option term, we analyze historical exercise experience as well as expected stock option exercise patterns.
	The following table summarizes details regarding stock options granted under our equity incentive plans for the year ended December 31, 2014:
		December 31, 2014
		Options			Weighted		Weighted		Aggregate
					Average		Average		Intrinsic Value
					Exercise Price		Remaining		($ in millions)
							Contractual
							Term
	Outstanding at beginning of year		2,819,676		$	21.31
	Granted		1,391,776			25.75
	Exercised		(494,576	)		19.43
	Expired and/or forfeited		(720,493	)		25.81
	Outstanding at end of year		2,996,383		$	22.6		7.7	$	60,546
	Outstanding at end of year—vested and unvested expected to vest		2,688,944		$	22.6		7.6	$	54,410
	Exercisable at end of year		946,787		$	22.47		6	$	60,459
	The weighted average grant date fair value of stock options granted during 2014, 2013 and 2012 was $10.63, $8.60 and $6.90, respectively. A total of 668,321 stock options vested during 2014. The total grant date fair value of options that vested during 2014, 2013 and 2012 was $5.7 million, $4.5 million and $5.5 million, respectively. The aggregate intrinsic value of options exercised during 2014, 2013 and 2012, excluding purchases made pursuant to our employee stock purchase plans, measured as of the exercise date, was approximately $5.9 million, $1.0 million and $0.1 million, respectively. The intrinsic value of a stock option is the amount by which the fair market value of the underlying stock on a specific date exceeds the exercise price of the common stock option.
	In 2014, we issued an aggregate of 356,626 RSUs to our employees and directors (including inducement grants). In general, these grants vest on an annual basis over a four year period. The estimated fair value of RSUs granted was determined at the grant date based upon the quoted market price per share on the date of the grant.
	The following table summarizes details regarding RSUs granted under our equity incentive plans for the year ended December 31, 2014:
		December 31, 2014
		Unvested			Weighted
		Restricted			Average Grant
		Stock Units			Date Fair Value
	Outstanding at beginning of year		465,394		$	17.28
	Granted		356,626			22.88
	Vested		(151,518	)		17.71
	Forfeited		(129,276	)		18.25
	Outstanding at end of year		541,226		$	20.62
Outstanding at end of year and expected to vest		465,686		$	20.59
The weighted average grant date fair value of RSUs granted during 2014, 2013 and 2012 was $22.88, $16.31 and $15.64, respectively. The total grant date fair of RSUs that vested during 2014, 2013 and 2012 was $2.7 million, $2.8 million and $3.5 million, respectively.
At December 31, 2014, the amount of unrecorded equity-based compensation expense for both option and RSU awards, net of forfeitures, attributable to future periods was approximately $24.0 million. Of this amount, $15.9 million was associated with stock options and is expected to be amortized on a straight-line basis to expense over a weighted average period of approximately two years, and $8.1 million was associated with RSUs and is expected to be amortized to on a straight-line basis to expense over a weighted average period of approximately two years. Such amounts will be amortized primarily to research and development or selling, general and administrative expense. These future estimates are subject to change based upon a variety of future events, which include, but are not limited to, changes in estimated forfeiture rates, employee turnover, and the issuance of new stock options and other equity-based awards.

Employee_Savings_Plan

Employee Savings Plan	12 Months Ended
	Dec. 31, 2014
Employee Savings Plan
Employee Savings Plan
	N.    EMPLOYEE SAVINGS PLAN
	We provide a 401(k) Plan to our employees by which they may defer compensation for income tax purposes under Section 401(k) of the Internal Revenue Code. Each employee may elect to defer a percentage of his or her salary up to a specified maximum. Our 401(k) Plan provides, among other things, for a company contribution of 3% of each employee's combined salary and certain other compensation for the plan year. Salary deferred by employees and contributions by us to the 401(k) Plan are not taxable to employees until withdrawn from the 401(k) Plan and contributions are deductible by us when made. The amount of our company contribution for the 401(k) Plan was $0.8 million, $0.7 million, and $0.8 million for 2014, 2013 and 2012, respectively.

Stockholders_Equity

Stockholders' Equity	12 Months Ended
	Dec. 31, 2014
Stockholders' Equity
Stockholders' Equity
	O.    STOCKHOLDERS' EQUITY
	Our certificate of incorporation authorizes our Board to issue preferred stock from time to time in one or more series. The rights, preferences, restrictions, qualifications and limitations of such stock are determined by our Board. In September 2009, our Board adopted a shareholder rights plan (the "Rights Agreement").
	On February 11, 2014, in connection with the pricing of the Convertible Notes, we and American Stock Transfer & Trust Company, LLC (the "Rights Agent") entered into an amendment (the "Convertible Notes Amendment") to the Rights Agreement. The Convertible Notes Amendment, among other things, provides that, notwithstanding anything in the Rights Agreement to the contrary, each of JPMorgan Chase Bank, National Association, London Branch, Morgan Stanley & Co. International plc and Royal Bank of Canada (together the "Call Spread Counterparties") 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 another 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"). 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.

Business_Segments

Business Segments	12 Months Ended
	Dec. 31, 2014
Business Segments
Business Segments
	P.     BUSINESS SEGMENTS
	We have determined that we conduct our operations in one business segment: the manufacture, development and commercialization of products for use in treating various conditions. Long-lived assets consist entirely of property and equipment and are located in the U.S. for all periods presented.

Commitments_and_Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2014
Commitments and Contingencies
Commitments and Contingencies
	Q.    COMMITMENTS AND CONTINGENCIES
	Commitments
	Our long-term contractual obligations include commitments and estimated purchase obligations entered into in the normal course of business. These include commitments related to purchases of inventory of our products, research and development service agreements, operating leases and selling, general and administrative obligations, and milestone payments due under our licensing and acquisition agreements.
	Operating and Facility Lease Obligations
	We have entered into certain operating leases, including certain office equipment and automobiles, which expire through 2017. Expense associated with these operating leases, including previous leases of certain automobiles, amounted to approximately $0.2 million, $(0.3) million and, $0.9 million for 2014, 2013 and 2012, respectively. The net credit for operating lease expense in 2013 is due to the excess of the sales value of certain automobiles we previously leased over the contracted value in connection with the 2013 termination of the automobile leases and the subsequent sales of the automobiles by the leasing companies. Future minimum lease payments associated with all non-cancellable equipment, service and lease agreements, excluding facility-related leases are approximately $0.6 million for 2015.
	In June 2013, we entered into a lease agreement with BP Bay Colony LLC (the "Landlord") for the lease of certain real property located at 1100 Winter Street, Waltham, Massachusetts (the "Waltham Premises") for use as our principal executive offices. Beginning in September 2013, the initial term of the lease is five years and two months with one five-year extension term at our option. During the extension period, the base rent will be an amount agreed upon by us and the Landlord. In addition to base rent, we are also required to pay a proportionate share of the Landlord's operating costs.
	The Landlord agreed to pay for certain agreed-upon improvements to the Waltham Premises and we agreed to pay for any increased costs due to changes by us to the agreed-upon plans. We record all tenant improvements paid by us as leasehold improvements and amortize these improvements over the shorter of the estimated useful life of the improvement or the remaining life of the initial lease term. Amortization of leasehold improvements is included in depreciation expense.
	In addition, in connection with our facility lease for the Waltham Premises, in June 2013 we delivered to the Landlord a security deposit of $0.4 million in the form of an irrevocable letter of credit. This security deposit will be reduced to $0.3 million on the second anniversary of the date the lease commenced. The cash securing this letter of credit is classified on our balance sheet as of December 31, 2014 and 2013 as a long-term asset and is restricted in its use.
	In June 2013, we also entered into an Assignment and Assumption of Lease (the "Assignment Agreement") with Shire Human Genetic Therapies, Inc. ("Shire") effecting the assignment to Shire of the right to occupy our former office space located at 100 Hayden Avenue, Lexington, Massachusetts (the "Prior Space"). Under the Assignment Agreement, the assignment to Shire became effective on September 21, 2013, the date of our departure from the Prior Space, and Shire assumed all of our obligations as the tenant of the Prior Space. The Assignment Agreement also provided for the conveyance of furniture and other personal property by us to Shire.
	In connection with our acquisition of Lumara Health, we have assumed the lease of certain real property located at 16640 Chesterfield Grove Road, Chesterfield, Missouri (the "St. Louis Premises"), which we are currently using as temporary office space for Lumara Health employees as they relocate to the Waltham Premises. Beginning in September 2013, the initial term of the lease is five years and two months. In addition to base rent, we are also required to pay a proportionate share of the Landlord's operating costs. We are attempting to sublease the St. Louis Premises and if successful, future operating lease commitments will be partially offset by proceeds received from the sublease.
	Future minimum payments under our non-cancelable facility-related leases as of December 31, 2014 are as follows (in thousands):
	Period	Minimum Lease
		Payments
	Year Ended December 31, 2015	$	1,451
	Year Ended December 31, 2016		1,456
	Year Ended December 31, 2017		1,462
	Year Ended December 31, 2018		1,174
	Total	$	5,543
	Facility-related rent expense, net of deferred rent amortization, for the Waltham Premises and the Prior Space, as applicable, was $0.8 million, $1.5 million and $1.7 million for 2014, 2013, and 2012. Facility-related rent expense for the St. Louis Premises was less than $0.1 million from November 12, 2014 through December 31, 2014.
	Debt Obligations
	Our long-term debt obligations reflect our obligations under the Convertible Notes and Term Loan Facility to pay interest on the $540.0 million aggregate principal amount and to make scheduled principal payments on the Term Loan Facility and principal payments at maturity or upon conversion, in the case of the Convertible Notes.
	Purchase Commitments
	During 2014, we entered into various agreements with third parties for which we had remaining purchase commitments of approximately $4.8 million as of December 31, 2014. These agreements principally related to certain purchase orders for the production of our products, certain outsourced commercial activities, manufacturing commitments, our information technology infrastructure, and other operational activities.
	Contingent Consideration Related to Business Combinations
	In connection with our acquisition of Lumara Health in November 2014, we agreed to pay up to an additional $350.0 million based on the achievement of certain sales milestones. Due to the contingent nature of these milestone payments, we cannot predict the amount or timing of such payments. See Note C, "Business Combinations," for more information on the Lumara Health acquisition and related milestone payments.
	Other Funding Commitments
	As of December 31, 2014, we had several ongoing clinical studies in various clinical trial stages. Our most significant clinical trial expenditures were to clinical research organizations ("CROs"). The contracts with CROs are generally cancellable, with notice, at our option. We have recorded accrued expenses in our consolidated balance sheet of approximately $1.9 million representing expenses incurred with these organizations as of December 31, 2014, net of any amounts prepaid to these CROs.
	Severance Arrangements
	We have entered into employment agreements or other arrangements with most of our executive officers and certain other employees, which provide for the continuation of salary and certain benefits and, in certain instances, the acceleration of the vesting of certain equity awards to such individuals in the event that the individual is terminated other than for cause, as defined in the applicable employment agreements or arrangements.
	Indemnification Obligations
	As permitted under Delaware law, pursuant to our certificate of incorporation, by-laws and agreements with all of our current directors, executive officers, and certain of our employees, we are obligated to indemnify such individuals for certain events or occurrences while the officer, director or employee is, or was, serving at our request in such capacity. The maximum potential amount of future payments we could be required to make under these indemnification obligations is not capped. Our director and officer insurance policy limits our initial exposure to $1.0 million and our policy provides significant coverage. As a result, we believe the estimated fair value of these indemnification obligations is likely to be immaterial.
	We are also a party to a number of other agreements entered into in the ordinary course of business, which contain typical provisions and which obligate us to indemnify the other parties to such agreements upon the occurrence of certain events. Such indemnification obligations are usually in effect from the date of execution of the applicable agreement for a period equal to the applicable statute of limitations. Our aggregate maximum potential future liability under such indemnification provisions is uncertain. Except for expenses we incurred related to the Silverstrand class action lawsuit, described below, filed against us in March 2010, we have not incurred any expenses as a result of such indemnification provisions. Accordingly, we have determined that the estimated aggregate fair value of our potential liabilities under such indemnification provisions is not significant, and we have not recorded any liability related to such indemnification.
	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 that 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, 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.
	Silverstrand Class Action
	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, 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. After litigating the class action lawsuit for several years, on September 12, 2014, we and the other defendants entered into a stipulation of settlement with the lead plaintiffs (on behalf of themselves and each of the class members) to 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 and certain other persons, and dismissal of the lawsuit with prejudice, we 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 were notified of the proposed settlement and the procedures by which they could seek to recover from the settlement fund, object to the settlement or request to be excluded from the settlement class and on January 30, 2015, the stipulation of settlement was approved by the U.S. District Court. The U.S. District Court entered final judgment on February 2, 2015. Any appeals of the settlement are due by March 4, 2015. We have recorded the $3.75 million settlement amount in prepaid and other current assets and a corresponding amount in accrued expenses on our consolidated balance sheet as of December 31, 2014, as the settlement amount will be fully covered by our insurance carrier. There was no impact to our consolidated statement of operations for the year ended December 31, 2014.
	Makena Securities Litigation
	On October 19, 2011, plaintiff Frank Julianello filed a complaint against Lumara Health (then-named K-V Pharmaceutical Company (“K-V Pharmaceutical”,) and certain individual defendants, in the United States District Court for the Eastern District of Missouri (the "Court"), alleging violations of the anti-fraud provisions of the federal securities laws on behalf of all purchasers of the publicly traded securities of Lumara Health between February 14, 2011 and April 4, 2011. The complaint alleges class members were damaged by paying artificially inflated stock prices due to Lumara Health's purportedly misleading statements regarding Makena related to access and exclusivity. On October 31, 2011, plaintiff Ramakrishna Mukku filed a complaint against Lumara Health, in the United States District Court for the Eastern District of Missouri, alleging violations of the anti-fraud provisions of the federal securities laws on behalf of all purchasers of the publicly traded securities of Lumara Health between February 14, 2011 and April 4, 2011. The complaint alleges class members were damaged by paying artificially inflated stock prices due to Lumara Health's purportedly misleading statements regarding Makena related to access and exclusivity. On November 2, 2011, plaintiff Hoichi Cheong filed a complaint against Lumara Health, in the United States District Court for the Eastern District of Missouri, on behalf of purchasers of the securities of Lumara Health, who purchased or otherwise acquired K-V Pharmaceutical securities between February 14, 2011 and April 4, 2011, seeking to pursue remedies under the Exchange Act. The complaint alleges class members were damaged by purchasing artificially inflated stock prices due to Lumara Health's purportedly misleading statements regarding Makena related to access and exclusivity. On March 8, 2012, the Julianello, Mukku and Cheong cases were consolidated and the consolidated action is now styled In Re K-V Pharmaceutical Company Securities Litigation, Case No. 4:11-CV-1816-AGF. On May 4, 2012, the Court appointed Lori Anderson as Lead Plaintiff in the matter. On April 22, 2013, the individual defendants moved to dismiss the complaint and oral argument was held before the Court on November 26, 2013 LumaraHealth joined in the motion to dismiss on February 10, 2014. On March 27, 2014, the Court entered an order granting Lumara Health's motion to dismiss the class action complaint without prejudice to the Plaintiffs' ability to file a second amended complaint with respect to a limited issue of whether Lumara Health's statements about Lumara Health's financial assistance program for Makena were materially false or misleading. On April 16, 2014, the Plaintiff's filed a motion to reconsider asking the Court to reconsider its order restricting the scope of Plaintiff's ability to amend its complaint. The Court denied Plaintiff's motion to reconsider and entered a judgment granting Lumara Health's motion to dismiss on June 6, 2014. On July 1, 2014, Plaintiffs filed a Notice of Appeal with the Eighth Circuit Court of Appeals and briefs have been submitted to the Court. The Court of Appeals has set March 12, 2015 as the date for oral argument.
	European Patent Organization Appeal
	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. In the event that we withdraw our appeal or that 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 year ended December 31, 2014. However, any future unfavorable outcome in this matter could negatively affect the magnitude and timing of future revenues. 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 December 31, 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 December 31, 2014. We expense legal costs as they are incurred.

Collaborative_Agreements

Collaborative Agreements	12 Months Ended
	Dec. 31, 2014
Collaborative Agreements
Collaborative Agreements
	R.    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-state development assets.
	Takeda
	In March 2010, we entered into the Takeda Agreement, as amended in June 2012, under which we granted exclusive rights to Takeda to develop and commercialize Feraheme as a therapeutic agent in certain agreed-upon territories. In February 2014, we entered into a supply agreement with Takeda, which provides the terms under which we sell Feraheme to Takeda in order for Takeda to meet its requirements for commercial use of Feraheme in its licensed territories (the "Supply Agreement"). On December 29, 2014, we entered into the Takeda Termination Agreement to terminate the Amended Takeda Agreement and we will regain all worldwide development and commercialization rights for Feraheme following the transfer of the outstanding marketing authorizations to us. Pursuant to the Takeda Termination Agreement, we and Takeda have agreed to effectuate the termination of the Amended Takeda Agreement on a rolling basis, whereby the termination will be effective for a particular geographic territory (e.g., countries under the regulatory jurisdictions of Health Canada, the EMA and SwissMedic) upon the earlier of effectiveness of the transfer to us or a Withdrawal (as defined below) of the marketing authorization for such territory, with the final effective termination date to be on the third such effective date ("Termination Date"). We have recently come to a mutual decision with Takeda to initiate withdrawal of the marketing authorization for Rienso in the EU and Switzerland. We are currently assessing the commercial opportunity for Feraheme in Canada.
	Under the Amended Takeda Agreement, except under limited circumstances, we retained the right to manufacture Feraheme and, accordingly, were responsible for supply of Feraheme to Takeda at a fixed price per unit. We were also responsible for conducting, and bearing the costs related to, certain pre-defined clinical studies. We determined that our obligations under the Amended Takeda Agreement had not changed from those under the original Takeda Agreement and included the following four deliverables: the license, access to future know-how and improvements to the Feraheme technology, regulatory and clinical research activities, and the manufacturing and supply of product. Pursuant to the accounting guidance in effect in March 2010, when we signed the original Takeda Agreement and which governed revenue recognition on multiple element arrangements, we evaluated the four deliverables under the original Takeda Agreement and determined that our obligation to provide manufacturing supply of product met the criteria for separation and was therefore treated as a single unit of accounting, which we refer to as the supply unit of accounting. Further, we concluded that the license was not separable from the undelivered future know-how and technological improvements or the undelivered regulatory and clinical research activities. Accordingly, these deliverables were being combined and also treated as a single unit of accounting, which we refer to as the combined unit of accounting. With respect to the combined unit of accounting, our then obligation to provide access to our future know-how and technological improvements was the final deliverable and was an obligation which existed throughout the term of the Amended Takeda Agreement.
	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 could not reasonably estimate the total level of effort required to complete the obligations under the combined deliverable, we were recognizing the entire $60.0 million upfront payment and the $1.0 million reimbursed to us in 2010, 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 represented the then current patent life of Feraheme and our best estimate of the period over which we were to substantively perform our obligations.
	In June 2012, we earned a $15.0 million milestone payment from Takeda based on the European Commission marketing authorization for ferumoxytol. We deemed the $15.0 million milestone payment as a substantive milestone and therefore recognized the full amount as revenue. During 2012, we received an aggregate of $18.0 million in milestone payments from Takeda associated with the commercial launches of Feraheme in the EU and Canada, which we deemed to be non-substantive milestone payments. Revenues related to the combined unit of accounting are recorded in license fee and other collaboration revenues in our consolidated statement of operations. In 2014, we recognized $8.2 million in revenues associated with the amortization of the upfront and milestone payments in license fees and other collaboration revenues in our consolidated statement of operations, including the acceleration of $0.3 million of upfront and milestone payments as a result of the termination of the Amended Takeda Agreement. We have classified all remaining upfront and milestone payments received to date as short-term deferred revenues at December 31, 2014, and we expect to recognize the remaining balance of the deferred revenue related to Takeda within the next 12 months. In addition, we recorded $3.2 million related to the Takeda Termination Agreement as deferred revenue at December 31, 2014.
	Prior to entering into the December 2014 Takeda Termination Agreement, under the terms of the Amended Takeda Agreement, Takeda was 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 were acting as the principal in carrying out these services, any reimbursement payments received from Takeda were recorded in license fee and other collaboration revenues in our consolidated statement of operations to match the costs that we incurred during the period in which we performed those services. We recorded $1.7 million, $0.5 million and $0.4 million for 2014, 2013 and 2012, respectively, associated with other reimbursement revenues received from Takeda. We have assumed any post-marketing obligations of Takeda as part of the Takeda Termination Agreement, including costs that otherwise would have been Takeda's obligation under the Amended Takeda Agreement for the ongoing pediatric studies and the initiated multi-center clinical trial to be conducted to determine the safety and efficacy of repeat doses of Feraheme for the treatment of IDA in patients with hemodialysis dependent CKD, including a treatment arm with iron sucrose using a magnetic resonance imaging sub-analysis. In connection with our decision to withdraw the marketing authorization for Rienso in the EU and Switzerland, we may modify or terminate clinical trials being conducted as part of our post-approval commitments to the EMA.
	Prior to entering into the December 2014 Takeda Termination Agreement, at the time of shipment, we deferred recognition of all revenue for Feraheme sold to Takeda in our consolidated balance sheets. We recognized revenues from product sales to Takeda, the related cost of product sales, and any royalty revenues due from Takeda, in our consolidated statement of operations at the time Takeda reported to us that sales had been made to their customers. During 2014, we recognized $3.5 million in product sales and royalty revenue and $2.8 million of cost of product sales related to the Amended Takeda Agreement, which included all amounts previously deferred prior to the termination of the Amended Takeda Agreement, and we have included in other product sales and royalties, and cost of product sales, respectively, in our consolidated statement of operations.
	In connection with each Termination Date and in accordance with the terms of the Takeda Termination Agreement, Takeda is obligated, with respect to the applicable terminated territory, to transfer and assign to us all applicable regulatory materials and approvals and certain product data, unlabeled inventory, third party contracts intellectual property rights and know-how to us, and to grant us an exclusive license for certain Takeda technology used and applied to commercialize Feraheme in the applicable territory. The Takeda Termination Agreement also details the regulatory activities each party is required to perform in connection with transferring the marketing authorization from Takeda to us in each of the territories and the allocation of the costs of such activities. We and Takeda have agreed to use commercially reasonable efforts to transfer all required activities to us on a territory-by-territory basis within 60 days after the applicable Termination Date (subject to a 30-day extension upon our request and Takeda's consent). In addition, Takeda is obligated pursuant to the Takeda Termination Agreement to provide transition assistance to us, at no cost to us, for up to 180 days after each Termination Date for the applicable termination territory. With Takeda's consent (which shall not be unreasonably withheld or delayed), we may extend the transition services period for a terminated territory for a period of time reasonably necessary to complete any services that cannot be reasonably transitioned to us during the initial 180-day period, which extension will not exceed an additional 180 days. If we request, and Takeda agrees to conduct, additional transition services after the end of the applicable transition services period, as may be extended, we will reimburse Takeda's fully burdened costs for such additional services plus 5%.
	The Takeda Termination Agreement also provides that if the marketing authorization for the product is suspended in a particular territory and the parties are prevented from completing the transfer of such marketing authorization to us within 120 days after such suspension due to applicable laws or any regulatory requirements or restrictions, or if we do not fulfill our obligations to initiate marketing authorization transfer by the agreed-upon, territory-specific deadline, Takeda will have the right, in Takeda's sole discretion, to withdraw such marketing authorization (a "Withdrawal").
	In consideration for the early termination of the Amended Takeda Agreement and the activities to be performed by us earlier than contemplated under the Amended Takeda Agreement, and in lieu of any future cost-sharing and milestone payments contemplated by the Amended Takeda Agreement, Takeda agreed to make certain payments to us, subject to certain terms and conditions, including up to approximately $6.7 million in connection with clinical study obligations, pharmacovigilance activities, regulatory filings and support, commercialization and back-office support and distribution expenditures and a $3.0 million milestone payment payable subject to certain regulatory conditions.
	Additionally, the supply agreement we entered into with Takeda in February 2014, together with the Amended Takeda Agreement, which continues in effect until the expiration or termination of the Amended Takeda Agreement, will also terminate as of the respective Termination Date in the applicable geographic territory.
	3SBio
	In 2008, we entered into a Collaboration and Exclusive License Agreement (the "3SBio License Agreement") and a Supply Agreement with 3SBio Inc. 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, the recognition of which had been deferred. 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.
	PlasmaTech
	Please refer to Note C, "Business Combinations," for a detailed description of the MuGard License Agreement.

Debt

Debt	12 Months Ended
	Dec. 31, 2014
Debt
Debt
	S.     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 (which are currently convertible) will be convertible into cash, shares of our common stock, or a combination thereof, at our election (subject to certain limitations in the Term Loan Facility), 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 (subject to certain limitations in the Term Loan Facility). 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 December 31, 2014 consisted of the following (in thousands):
			December 31, 2014
	Liability component:
	Principal		$	200,000
	Less: debt discount, net			(32,559	)
	Net carrying amount		$	167,441
	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 December 31, 2014, the carrying value of the Convertible Notes was $167.4 million and the fair value of the Convertible Notes was $332.0 million. The effective interest rate on the liability component was 7.23% for the period from the date of issuance through December 31, 2014. The following table sets forth total interest expense recognized related to the Convertible Notes during the year ended December 31, 2014 (in thousands):
			Year Ended
			December 31, 2014
	Contractual interest expense		$	4,375
	Amortization of debt issuance costs			800
	Amortization of debt discount			5,629
	Total interest expense		$	10,804
	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 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.
	In February 2014, 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.
	Term Loan Facility
	On November 12, 2014 (the "Closing Date"), in connection with the acquisition of Lumara Health, we entered into the Term Loan Facility. The proceeds of the Term Loan Facility borrowed on the Closing Date were used to finance, in part, the Cash Consideration.  We borrowed $340.0 million under the Term Loan Facility to fund a portion of the purchase price of Lumara Health. We realized net proceeds of $327.5 million after deducting $12.5 million of original issue discount costs and other lender fees and expenses. At December 31, 2014, the carrying value of the outstanding borrowings, net of unamortized original issue costs and other lender fees and expenses, was $327.9 million.
	The Term Loan Facility provides for the aggregate principal amount of $340.0 million and allows for the incurrence of incremental term loans in an amount up to $40.0 million on the terms and subject to the conditions set forth in the Term Loan Facility. The Term Loan Facility bears interest, at our option, at either the Eurodollar rate plus a margin of 6.25% or the prime rate plus a margin of 5.25%. The Eurodollar rate is subject to a 1.00% floor and the prime rate is subject to a 2.00% floor. As of December 31, 2014 the stated interest rate was 7.25% and the effective interest rate was 8.55%.
	We must repay the Term Loan Facility in installments of (a) $8.5 million per quarter due on the last day of each quarter beginning with the quarter ending March 31, 2015 through the quarter ending December 31, 2015, and (b) $12.8 million per quarter due on the last day of each quarter beginning with the quarter ending March 31, 2016 through the quarter ending September 30, 2020, with the balance due in a final installment on November 12, 2020. The Term Loan Facility matures on November 12, 2020, except that the Term Loan Facility will mature on September 30, 2018 if:
	(c)	more than $25.0 million in aggregate principal amount of our Convertible Notes remain outstanding and not converted to common stock or refinanced and replaced with debt that matures following, and has no amortization prior to, the date that is six and one half years following the Closing Date; and
	(b)	the aggregate principal amount of all the Term Loan Facility (including all undrawn incremental commitments) is greater than $50.0 million on and as of such date (the "Maturity Date").
	Additionally, the Term Loan Facility includes an annual mandatory prepayment of the Term Loan Facility from 75% of our excess cash flow as measured on an annual basis, with step-downs to 50%, 25% and 0% of our excess cash flow if our Total Net Leverage Ratio (as defined in the Term Loan Facility), tested as of the last day of our fiscal year, is less than or equal to 2.00 to 1.00, 1.00 to 1.00 and 0.50 to 1.00, respectively. Excess cash flow is generally defined as our adjusted Earnings Before Interest, Taxes, Depreciation and Amortization ("EBITDA") less debt service costs, unfinanced capital expenditures, unfinanced acquisition expenditures, and current income taxes paid, as adjusted for changes in our working capital. Additionally, the Term Loan Facility requires mandatory prepayment of the term loan from the net cash proceeds of (i) certain debt issuances and (ii) certain asset sales outside the ordinary course of business and from proceeds of property insurance and condemnation events, in each case of this clause (ii) subject to our right to reinvest such proceeds in our business. Any voluntary prepayment or mandatory prepayment pursuant to the preceding sentence other than such prepayments not exceeding $50.0 million in the aggregate, shall be accompanied by a prepayment premium equal to (a) 2.0% of the principal amount of such prepayment, if such prepayment is made on or prior to the date that is twelve months after the Closing Date or (b) 1.0% of the principal amount of such prepayment, if such prepayment is made after the date that is twelve months after the Closing Date and on or prior to the date that is twenty-four months after the Closing Date.
	The Term Loan Facility has a lien on substantially all of our assets, including a pledge of 100% of the equity interests in our domestic subsidiaries and an obligation to pledge 65% of the equity interests in our direct foreign subsidiaries.
	The Term Loan Facility contains customary affirmative covenants for transactions of this type and other affirmative covenants agreed to by the parties, including, among others, the provision of annual and quarterly financial statements and compliance certificates, maintenance of property, insurance, compliance with laws and environmental matters. The Term Loan Facility contains customary negative covenants for transactions of this type and other negative covenants agreed to by the parties, including, among others, restrictions on the incurrence of indebtedness, granting of liens, making investments and acquisitions, paying dividends, repurchases of equity interests in the Company, entering into affiliate transactions and asset sales. The Term Loan Facility also provides for a number of customary events of default, including, among others, payment, bankruptcy, covenant, representation and warranty, change of control and judgment defaults. In addition, the Term Loan Facility contains certain restrictions regarding the use of our funds to pay certain debts.
	The Term Loan Facility requires that we comply with a Total Net Leverage Ratio. Under the terms of the Term Loan Facility, we must maintain a Total Net Leverage Ratio that is less than or equal to 4.60 to 1.00 for the fiscal quarter ended March 31, 2015 and declining over time to a range of 1.00 to 1.00 for the fiscal quarter ending September 30, 2017 through the Maturity Date. For purposes of testing our Total Net Leverage Ratio, we are permitted to net from our outstanding total indebtedness up to $25.0 million of its domestic unrestricted cash and cash equivalents. As of December 31, 2014, we were in compliance with these covenants.
	All obligations under the Term Loan Facility are unconditionally guaranteed by substantially all of our direct and indirect domestic subsidiaries. These guarantees are secured by substantially all of the present and future property and assets of the guarantors.
	Future annual principal payments on our long-term debt as of December 31, 2014 were as follows:
	2015		$	34,000
	2016			51,000
	2017			51,000
	2018			51,000
	2019			51,000
	Thereafter			102,000
	Total		$	340,000

Restructuring

Restructuring	12 Months Ended
	Dec. 31, 2014
Restructuring
Restructuring
	T.     RESTRUCTURING
	In connection with the Lumara Health acquisition, we initiated a restructuring program in the fourth quarter of 2014, which included severance benefits primarily related to certain former Lumara Health employees. As a result of the restructuring, we recorded charges of approximately $2.0 million in 2014. We expect to pay substantially all of these restructuring costs during 2015.
	The following table outlines the components of our restructuring expenses which were included in current liabilities for 2014 (in thousands):
		December 31, 2014
	Accrued restructuring, beginning of period	$	—
	Employee severance, benefits and related costs		2,023
	Payments		(70	)
	Accrued restructuring, end of period	$	1,953

Consolidated_Quarterly_Financi

Consolidated Quarterly Financial Data-Unaudited	12 Months Ended
	Dec. 31, 2014
Consolidated Quarterly Financial Data-Unaudited
Consolidated Quarterly Financial Data-Unaudited
	U.    CONSOLIDATED QUARTERLY FINANCIAL DATA—UNAUDITED
	The following tables provide unaudited consolidated quarterly financial data for 2014 and 2013 (in thousands, except per share data):
		March 31, 2014			June 30, 2014			September 30, 2014			December 31, 2014
	U.S. product sales, net	$	17,375		$	22,225		$	22,547		$	46,648
	License fee and other collaboration revenues		3,120			2,122			2,182			3,462
	Other product sales and royalties		340			455			765			3143
	Total revenues		20,835			24,802			25,494			53,253
	Cost of product sales		2,837			2,743			2,968			11,758
	Gross margin		17,998			22,059			22,526			41,495
	Operating expenses		23,989			20,824			18,233			44,869
	Interest expense		(1,476	)		(3,051	)		(3,129	)		(7,041	)
	Interest and dividend income, net		265			253			291			166
	Gains on sale of assets		100			2			—			1
	Gains on investments, net		—			14			3			97
	Net income (loss) before income taxes		(7,102	)		(1,547	)		1,458			(10,151	)
	Income tax benefit		—			—			—			153,159
	Net income (loss)	$	(7,102	)	$	(1,547	)	$	1,458		$	143,008
	Net income (loss) per share—basic	$	(0.33	)	$	(0.07	)	$	0.07		$	5.98
	Net income (loss) per share—diluted	$	(0.33	)	$	(0.07	)	$	0.07		$	4.67
		March 31, 2013			June 30, 2013			September 30, 2013			December 31, 2013
	U.S. Feraheme product sales, net	$	15,578		$	17,456		$	19,347		$	18,981
	License fee and other collaboration revenues		2,003			2,055			1,998			2,329
	Other product sales and royalties		299			138			271			401
	Total revenues		17,880			19,649			21,616			21,711
	Cost of product sales		2,942			3,145			2,547			3,326
	Gross margin		14,938			16,504			19,069			18,385
	Operating expenses		19,409			19,260			19,464			22,380
	Interest and dividend income, net		271			256			246			278
	Gains on assets held for sale		299			566			—			59
	Gains on investments, net		6			26			4			4
	Net loss	$	(3,895	)	$	(1,908	)	$	(145	)	$	(3,654	)
	Net loss per share—basic and diluted	$	(0.18	)	$	(0.09	)	$	(0.01	)	$	(0.17	)
	Quarterly loss per share totals differ from annual loss per share totals due to rounding. On November 12, 2014, we completed our acquisition of Lumara Health and recorded $22.5 million in Makena sales in 2014 and additional operating costs incurred as a result of the acquisition.

Valuation_and_Qualifying_Accou

Valuation and Qualifying Accounts	12 Months Ended
	Dec. 31, 2014
Valuation and Qualifying Accounts
Valuation and Qualifying Accounts
	V.     VALUATION AND QUALIFYING ACCOUNTS (IN THOUSANDS)
			Balance at		Additions(a)		Deductions			Balance at
			Beginning				Charged to			End of
			of Period				Reserves			Period
	Year ended December 31, 2014:
	Accounts receivable allowances(b)		$	2,683	$	59,372	$	(50,580	)	$	11,475
	Rebates, fees and returns reserves		$	4,799	$	52,079	$	(13,126	)	$	43,752
	Year ended December 31, 2013:
	Accounts receivable allowances(b)		$	1,771	$	37,098	$	(36,186	)	$	5,850
	Rebates, fees and returns reserves		$	3,448	$	11,820	$	(10,469	)	$	4,799
	Year ended December 31, 2012:
	Accounts receivable allowances(b)		$	1,822	$	26,517	$	(26,568	)	$	1,771
	Rebates, fees and returns reserves		$	5,943	$	6,729	$	(9,224	)	$	3,448
	(a)	Additions to sales discounts, rebates, fees and returns reserves are recorded as a reduction of revenues.
	(b)	We have not recorded an allowance for doubtful accounts in any of the years presented above. These accounts receivable allowances represent discounts and other chargebacks related to the provision for our product sales.

Recently_Issued_and_Proposed_A

Recently Issued and Proposed Accounting Pronouncements	12 Months Ended
	Dec. 31, 2014
Recently Issued and Proposed Accounting Pronouncements
Recently Issued and Proposed Accounting Pronouncements
	W.    RECENTLY ISSUED AND PROPOSED ACCOUNTING PRONOUNCEMENTS
	From time to time, new accounting pronouncements are issued by the Financial Accounting Standards Board ("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.
	In May 2014, the 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 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.

Summary_of_Significant_Account1

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2014
Summary of Significant Accounting Policies
Use of Estimates and Assumptions
	Use of Estimates and Assumptions
	The preparation of consolidated financial statements in conformity with accounting principles generally accepted in the U.S. ("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 to determine amounts and values of, but are not limited to: revenue related to product sales and collaboration agreements; product sales allowances and accruals; potential other-than-temporary impairment of investments; acquisition date fair value and subsequent fair value estimates used to assess impairment of long-lived assets, including goodwill, in-process research and development ("IPR&D") and other intangible assets; contingent consideration; debt obligations; accrued expenses; income taxes and equity-based compensation expense. Actual results could differ materially from those estimates.
Principles of Consolidation
	Basis of Presentation and Principles of Consolidation
	The accompanying consolidated financial statements have been prepared in conformity with GAAP and include the accounts of our wholly owned subsidiaries. All intercompany balances and transactions have been eliminated in consolidation. As of November 12, 2014 (the "Lumara Acquisition Date"), the operating results of Lumara Health have been consolidated with ours. See Note C, "Business Combinations," for additional information.
Cash and Cash Equivalents
	Cash and Cash Equivalents
	Cash and cash equivalents consist 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 December 31, 2014, substantially all of our cash and cash equivalents were held in either commercial bank accounts or money market funds.
Investments
	Investments
	We account for and classify our investments as either "available-for-sale," "trading," or "held-to-maturity," in accordance with current guidance related to the accounting and classification of certain investments in debt and equity securities. The determination of the appropriate classification by us is based on a variety of factors, including management's intent at the time of purchase. As of December 31, 2014 and 2013, all of our investments were classified as available-for-sale securities.
	Available-for-sale securities are those securities which we view as available for use in current operations, if needed. We generally classify our available-for-sale securities as short-term investments, even though the stated maturity date may be one year or more beyond the current balance sheet date. Available-for-sale investments are stated at fair value with their unrealized gains and losses included as a separate component of stockholders' equity entitled "Accumulated other comprehensive loss," until such gains and losses are realized or until an unrealized loss is considered other-than-temporary.
	We recognize and report other-than-temporary impairments of our debt securities in accordance with current accounting guidance, which requires that for debt securities with a decline in fair value below amortized cost basis, an other-than-temporary impairment exists if (a) we have the intent to sell the security or (b) it is more likely than not that we will be required to sell the security prior to recovery of its amortized cost basis. If either of these conditions is met, we recognize the difference between the amortized cost of the security and its fair value at the impairment measurement date in our consolidated statement of operations. If neither of these conditions is met, we must perform additional analyses to evaluate whether the unrealized loss is associated with the creditworthiness of the security rather than other factors, such as interest rates or market factors. These factors include evaluation of the security, issuer and other factors such as the duration of the period that, and extent to which, the fair value was less than cost basis, the financial health of and business outlook for the issuer, including industry and sector performance, operational and financing cash flow factors, overall market conditions and trends, underlying collateral, whether we have a favorable history in redeeming similar securities at prices at or above fair value, and credit ratings with respect to our investments provided by investments ratings agencies. If we determine from this analysis that we do not expect to receive cash flows sufficient to recover the entire amortized cost of the security, a credit loss exists. In this situation, the impairment is considered other-than-temporary and is recognized in our consolidated statement of operations.
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 acquisition-related contingent consideration.
	We also analyze when the volume and level of activity for an asset or liability have significantly decreased and when circumstances indicate that a transaction may not be considered orderly. In order to determine whether the volume and level of activity for an asset or liability have significantly decreased, we assess current activity as compared to normal market activity for the asset or liability. We rely on many factors such as trading volume, trading frequency, the levels at which market participants indicate their willingness to buy and sell our securities, as reported by market participants, and current market conditions. Using professional judgment and experience, we evaluate and weigh the relevance and significance of all applicable factors to determine if there has been a significant decrease in the volume and level of activity for an asset, group of similar assets or liabilities. Similarly, in order to identify transactions that are not orderly, we take into consideration the activity in the market which can influence the determination and occurrence of an orderly transaction. Also, we inquire as to whether there may have been restrictions on the marketing of the security to a single or limited number of participants. Where possible, we assess the financial condition of the seller to determine whether observed transactions may have been forced. If there is a significant disparity between the trading price for a security held by us as compared to the trading prices of similar recent transactions, we consider whether this disparity is an indicator of a disorderly trade. Using professional judgment and experience, we evaluate and weigh the relevance and significance of all applicable factors to determine if the evidence suggests that a transaction or group of similar transactions is not orderly. Based upon these procedures, we determined that market activity for our assets appeared normal and that transactions did not appear disorderly as of December 31, 2014 and 2013.
Inventory
	Inventory
	Inventory is stated at the lower of cost or market (net realizable value), with approximate cost being determined on a first-in, first-out basis. Prior to initial approval from the FDA or other regulatory agencies, we expense costs relating to the production of inventory in the period incurred. After such time as the product receives initial regulatory approval, we begin to capitalize the inventory costs related to the product. We continue to expense costs associated with clinical trial material as research and development expense.
	On a quarterly basis, we analyze our inventory levels to determine whether we have any obsolete, expired, or excess inventory. If any inventory is expected to expire prior to being sold, has a cost basis in excess of its net realizable value, is in excess of expected sales requirements as determined by internal sales forecasts, or fails to meet commercial sale specifications, the inventory is written-down through a charge to cost of product sales. The determination of whether inventory costs will be realizable requires estimates by management of future expected inventory requirements, based on sales forecasts. Once packaged, Feraheme currently has a shelf-life of five years in the U.S. and between two and three years outside of the U.S. and Makena has a shelf-life of three years. As a result of comparison to internal sales forecasts, we expect to fully realize the carrying value of our current Feraheme and Makena finished goods inventory. If actual market conditions are less favorable than those projected by management, inventory write-downs may be required. Charges for inventory write-downs are not reversed if it is later determined that the product is saleable.
Restricted Cash
	Restricted Cash
	As of December 31, 2014 and 2013, we classified $2.4 million and $3.3 million as restricted cash, respectively. The $2.4 million in our December 31, 2014 restricted cash balances includes $2.0 million held in a restricted fund previously established by Lumara Health in connection with its Chapter 11 plan of reorganization to pay potential claims against its former directors and officers and a $0.4 million security deposit delivered to the landlord of our Waltham, Massachusetts headquarters in the form of an irrevocable letter of credit. Included in the $3.3 million restricted cash balance as of December 31, 2013 was a $2.9 million escrow payment related to a business development transaction that we did not complete as well as the $0.4 million security deposit related to our Waltham, Massachusetts headquarters described above. The escrow payment was returned to us in January 2014 and as such was classified as short-term as of December 31, 2013.
Property and Equipment
	Property and Equipment
	Property and equipment are recorded at cost and depreciated when placed into service using the straight-line method based on their estimated useful lives. Our laboratory and production equipment and furniture and fixtures are being depreciated over five years. Furniture, fixtures, and leasehold improvements associated with our facility lease are being depreciated over the shorter of their useful lives or the remaining life of the original lease (excluding optional lease renewal terms).
	Costs for capital assets not yet placed in service are capitalized on our balance sheets and will be depreciated in accordance with the above guidelines once placed into service. Costs for maintenance and repairs are expensed as incurred. Upon sale or other disposition of property and equipment, the cost and related depreciation are removed from the accounts and any resulting gain or loss is charged to our consolidated statement of operations. Long-lived assets to be held and used are evaluated for impairment whenever events or changes in circumstances indicate that the carrying value of the asset may not be recoverable. Determination of recoverability is based on an estimate of undiscounted future cash flows resulting from the use of the asset (asset group) and its eventual disposition. In the event such cash flows are not expected to be sufficient to recover the carrying amount of the assets, the assets are written down to their estimated fair values. Assets classified as held for sale are no longer subject to depreciation and are recorded at the lower of carrying value or estimated net realizable value.
Business Combinations
	Business Combinations
	We account for acquired businesses using the acquisition method of accounting, which requires that assets acquired and liabilities assumed be recognized at their estimated fair values as of the acquisition date. Acquisition-related costs are expensed as incurred. Any excess of the consideration transferred over the estimated fair values of the net assets acquired is recorded as goodwill.
Acquisition-related Contingent Consideration
	Acquisition-Related Contingent Consideration
	Contingent consideration arising from a business combination is included as part of the purchase price and is recognized at fair value as of the acquisition date. Subsequent to the acquisition date, we measure contingent consideration arrangements at fair value for each period until the contingency is resolved. These changes in fair value are recognized in our consolidated statements of operations. Changes in fair values reflect new information about the likelihood of the payment of the contingent consideration and the passage of time.
Goodwill and Intangible Assets
	Goodwill and Intangible Assets
	Goodwill represents the excess purchase price paid in a business combination over the fair value of identifiable net assets acquired. Goodwill is not amortized, but is reviewed for impairment on an annual basis or more frequently if indicators of impairment are present. We determine whether goodwill may be impaired by comparing the carrying value of the reporting unit, including goodwill, to the fair value of the reporting unit. If the fair value is less than the carrying amount, a more detailed analysis is performed to determine whether goodwill is impaired. The impairment loss, if any, is measured as the excess of the carrying value of the goodwill over the implied value of the goodwill and is recorded in our consolidated statements of operations.
	Finite-lived intangible assets are amortized to their estimated residual values over their estimated useful lives and reviewed for impairment if certain events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. When such facts and circumstances exist, management compares the projected undiscounted future cash flows associated with the asset over its estimated useful life against the carrying amount. The impairment loss, if any, is measured as the excess of the carrying amount of the asset over its fair value.
	Acquired IPR&D represents the fair value assigned to research and development assets that we acquire that have not been completed at the date of acquisition. The fair value of IPR&D acquired in a business combination is capitalized on our consolidated balance sheet at the acquisition-date fair value. IPR&D is not amortized, but is reviewed for impairment on an annual basis or more frequently if indicators of impairment are present, until completion or abandonment of the projects. If we determine that IPR&D becomes impaired or is abandoned, the carrying value of the IPR&D is written down to its fair value with the related impairment charge recognized in our consolidated statement of operations in the period in which the impairment occurs. Upon successful completion of each project and launch of the product, we will make a separate determination of the estimated useful life of the IPR&D intangible asset and the related amortization will be recorded as an expense prospectively over its estimated useful life.
	The projected discounted cash flow models used to estimate our IPR&D reflect significant assumptions regarding the estimates a market participant would make in order to evaluate a drug development asset including the following:
	•	Probability of successfully completing clinical trials and obtaining regulatory approval;
	•	Market size, market growth projections, and market share;
	•	Estimates regarding the timing of and the expected costs to advance our clinical programs to commercialization;
	•	Estimates of future cash flows from potential product sales; and
	•	a discount rate.
Patents
	Patents
	We expense all patent-related costs as incurred.
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. Product Sales, Net
	We record product sales allowances and accruals related to prompt payment discounts, chargebacks, government and other rebates, distributor, wholesaler and group purchasing organization ("GPO") fees, and product returns as a reduction of revenue in our consolidated statement of operations at the time product sales are recorded. Calculating these gross to net sales adjustments involves estimates and judgments based primarily on actual product sales data, forecasted customer buying patterns, and market research data related to utilization rates by various end-users. In addition, we also monitor our distribution channel to determine whether additional allowances or accruals are required based on inventory in our sales channel.
	An analysis of our U.S. product sales allowances and accruals for the years ended December 31, 2014, 2013 and 2012 is as follows (in thousands):
			Years Ended December 31,
			2014			2013			2012
	Provision for U.S. product sales allowances and accruals
	Discounts and chargebacks		$	55,420		$	37,098		$	26,517
	Government and other rebates			25,091			10,868			6,058
	Medicaid rebate reserve adjustment			—			(568	)		(621	)
	Returns			(1,160	)		952			(1,516	)
	Total provision for U.S. product sales allowances and accruals		$	79,351		$	48,350		$	30,438
	Total gross U.S. product sales		$	188,146		$	119,712		$	88,725
	Total provision for U.S. product sales allowances and accruals as a percent of total gross U.S. product sales			42%			40%			34%
	The increases in discounts and chargebacks and government and other rebates primarily reflects the addition of the Makena product to our portfolio as a result of the November 2014 acquisition of Lumara Health. In addition, as discussed below, we reduced our reserve for Feraheme product returns by approximately $1.8 million and $2.2 million during 2014 and 2012, respectively.
	Classification of U.S. Product Sales Allowances and Accruals
	Product sales allowances and accruals are primarily comprised of both direct and indirect fees, discounts and rebates and provisions for estimated product returns. Direct fees, discounts and rebates are contractual fees and price adjustments payable to wholesalers, specialty distributors and other customers that purchase products directly from us. Indirect fees, discounts and rebates are contractual price adjustments payable to healthcare providers and organizations, such as certain physicians, clinics, hospitals, GPOs, and dialysis organizations that typically do not purchase products directly from us but rather from wholesalers and specialty distributors. In accordance with guidance related to accounting for fees and consideration given by a vendor to a customer, including a reseller of a vendor's products, these fees, discounts and rebates are presumed to be a reduction of the selling price. Product sales allowances and accruals are based on definitive contractual agreements or legal requirements (such as Medicaid laws and regulations) related to the purchase and/or utilization of the product by these entities and are recorded in the same period that the related revenue is recognized. We estimate product sales allowances and accruals using either historical, actual and/or other data, including estimated patient usage, applicable contractual rebate rates, contract performance by the benefit providers, other current contractual and statutory requirements, historical market data based upon experience of our products and other products similar to them, specific known market events and trends such as competitive pricing and new product introductions, current and forecasted customer buying patterns and inventory levels, and the shelf life of our products. As part of this evaluation, we also review changes to federal and other legislation, changes to rebate contracts, changes in the level of discounts, and changes in product sales trends. Although allowances and accruals are recorded at the time of product sale, certain rebates are typically paid out, on average, up to three months or longer after the sale.
	Allowances against receivable balances primarily relate to prompt payment discounts, provider chargebacks and certain government agency rebates and are recorded at the time of sale, resulting in a reduction in product sales revenue and the reporting of product sales receivables net of allowances. Accruals related to Medicaid and provider volume rebates, wholesaler and distributor fees, GPO fees, other discounts to healthcare providers and product returns are recorded at the time of sale, resulting in a reduction in product sales revenue and the recording of an increase in accrued expenses.
	Discounts
	We typically offer a 2% prompt payment discount to our customers as an incentive to remit payment in accordance with the stated terms of the invoice, generally thirty days. Because we anticipate that those customers who are offered this discount will take advantage of the discount, we accrue 100% of the prompt payment discount, at the time of sale, based on the gross amount of each invoice. We adjust the accrual quarterly to reflect actual experience.
	Chargebacks
	Chargeback reserves represent our estimated obligations resulting from the difference between the prices at which we sell our products to wholesalers and the sales price ultimately paid to wholesalers under fixed price contracts by third-party payers, including governmental agencies. We determine our chargeback estimates based on actual product sales data and forecasted customer buying patterns. Actual chargeback amounts are determined at the time of resale to the qualified healthcare provider, and we generally issue credits for such amounts within several weeks of receiving notification from the wholesaler. Estimated chargeback amounts are recorded at the time of sale, and we adjust the allowance quarterly to reflect actual experience.
	Government and Other Rebates
	Government and other rebate reserves relate to our reimbursement arrangements with state Medicaid programs, and contractual or performance rebate agreements with certain classes of trade. We determine our estimates for Medicaid rebates, if applicable, based on actual product sales data and our historical product claims experience. In estimating these reserves, we provide for a Medicaid rebate associated with both those expected instances where Medicaid will act as the primary insurer as well as in those instances where we expect Medicaid will act as the secondary insurer. For rebates associated with reaching defined performance goals, we determine our estimates using actual product sales data and forecasted customer buying and utilization patterns. Rebate amounts generally are invoiced quarterly and are paid in arrears, and we expect to pay such amounts within several weeks of notification by the Medicaid or provider entity. Estimated government and other rebates are recorded at the time of sale and, with the exception of Medicaid as discussed below, we adjust the accrual quarterly to reflect actual experience.
	During 2013 and 2012, we revised our estimated Feraheme Medicaid reserve rate based on actual product-specific rebate claims received since the 2009 launch of Feraheme, our expectations of state level activities, and estimated rebate claims not yet submitted, which resulted in a reduction of our then estimated Medicaid rebate reserve related to prior period Feraheme sales of $0.6 million in each of the respective years. These changes in estimates were reflected as an increase in our net product sales for 2013 and 2012 and resulted in reductions to our gross to net percentages in those periods. The reduction of our estimated Medicaid rebate reserve had an impact of $0.03 per basic and diluted share for each of the respective years. We regularly assess our Medicaid reserve balance and the rate at which we accrue for claims against product sales. If we determine in future periods that our actual rebate experience is not indicative of expected claims, or if 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 net product sales in the period of the adjustment and could be significant.
	Distributor/Wholesaler and Group Purchasing Organization Fees
	Fees under our arrangements with distributors and wholesalers are usually based upon units of product purchased during the prior month or quarter and are usually paid by us within several weeks of our receipt of an invoice from the wholesaler or distributor, as the case may be. Fees under our arrangements with GPOs are usually based upon member purchases during the prior quarter and are generally billed by the GPO within 30 days after period end. Current accounting standards related to consideration given by a vendor to a customer, including a reseller of a vendor's products, specify that cash consideration given by a vendor to a customer is presumed to be a reduction of the selling price of the vendor's products or services and therefore should be characterized as a reduction of revenue. Consideration should be characterized as a cost incurred if we receive, or will receive, an identifiable benefit (goods or services) in exchange for the consideration and we can reasonably estimate the fair value of the benefit received. Because the fees we pay to wholesalers do not meet the foregoing conditions to be characterized as a cost, we have characterized these fees as a reduction of revenue and have included them in government and other rebates in the table above. We generally pay such amounts within several weeks of our receipt of an invoice from the distributor, wholesaler or GPO. Accordingly, we accrue the estimated fee due at the time of sale, based on the contracted price invoiced to the customer. We adjust the accrual quarterly to reflect actual experience.
	Product Returns
	Consistent with industry practice, we generally offer our wholesalers, specialty distributors and other customers a limited right to return our products based on the product's expiration date. Currently the expiration dates for Feraheme in the U.S., Makena and MuGard are five years, three years and three years, respectively. 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 of the product, the expense to store our products, and/or that our products are readily available for distribution. 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 2014, we reduced our reserve for Feraheme product returns by approximately $1.8 million, primarily as a result of a lower than expected rate of product returns. We did not significantly adjust our reserve for product returns during 2013. During 2012, we reduced our reserve for Feraheme product returns by approximately $2.2 million, primarily as a result of a lower than expected rate of product returns as well as the lapse of the product return period on certain manufactured Feraheme lots. The reduction of our reserve had an impact of increasing our 2014 net income by $0.12 and $0.14 per basic and diluted share, respectively, and by $0.10 per basic and diluted share in 2012. 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 and continue to gain additional experience with return rates for Makena, 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.
	Other Product Sales and Royalties
	Other product sales and royalties primarily included Feraheme product sales to Takeda and royalties from Takeda as well as net product sales of MuGard. Prior to the Takeda Termination Agreement, we recorded all product sales of Feraheme sold to Takeda in deferred revenues in our consolidated balance sheet. We recognized these deferred revenues, and the associated cost of product sales, in our consolidated statement of operations at the time Takeda reported to us that sales had been made to its customers. At December 31, 2014, as the result of terminating the Amended Takeda Agreement, we recognized these remaining balances of deferred revenues and associated cost of product sales.
	License Fee and Other Collaboration Revenues
	The terms of product development and commercialization agreements entered into between us and our collaborative licensees may include non-refundable license fees, payments based on the achievement of certain milestones and performance goals, reimbursement of certain out-of-pocket costs, payment for manufacturing services, and royalties on product sales. We recognize license fee and research and development revenue under collaborative arrangements over the term of the applicable agreements using a proportional performance model, if practical. Otherwise, we recognize such revenue on a straight-line basis. Under this model, revenue is generally recognized in an amount equal to the lesser of the amount due under the agreements or an amount based on the proportional performance to date. In cases where project costs or other performance metrics are not estimable but there is an established contract period, revenues are recognized on a straight-line basis over the term of the relevant agreement. In cases where we are reimbursed for certain research and development costs associated with our collaboration agreements and where we are acting as the principal in carrying out these services, any reimbursement payments are recorded in license fee and other collaboration revenues in our consolidated statement of operations to match the costs that we incur during the period in which we perform those services. Nonrefundable payments and fees are recorded as deferred revenue upon receipt and may require deferral of revenue recognition to future periods.
	Multiple Element Arrangements and Milestone Payments
	We evaluate revenue from arrangements that have multiple elements to determine whether the components of the arrangement represent separate units of accounting as defined in the accounting guidance related to revenue arrangements with multiple deliverables. Under current accounting guidance, which governs any agreements that contain multiple elements that are either entered into or materially modified subsequent to January 1, 2011, companies are required to establish the fair value of undelivered products and services based on a separate revenue recognition process using management's best estimate of the selling price for an undelivered item when there is no vendor-specific objective evidence or third-party evidence to determine the fair value of that undelivered item. Agreements entered into prior to January 1, 2011, that have not been materially modified are accounted for under previous accounting guidance, which provides that an element of a contract can be accounted for separately if the delivered elements have standalone value and the fair value of all undelivered elements is determinable. If an element is considered to have standalone value but the fair value of any of the undelivered items cannot be determined, all elements of the arrangement are recognized as revenue as a single unit of accounting over the period of performance for such undelivered items or services. Significant management judgment is required in determining what elements constitute deliverables and what deliverables or combination of deliverables should be considered units of accounting.
	When multiple deliverables are combined and accounted for as a single unit of accounting, we base our revenue recognition pattern on the last to be delivered element. Revenue is recognized using either a proportional performance or straight-line method, depending on whether we can reasonably estimate the level of effort required to complete our performance obligations under an arrangement and whether such performance obligations are provided on a best-efforts basis. To the extent we cannot reasonably estimate our performance obligations, we recognize revenue on a straight-line basis over the period we expect to complete our performance obligations. Significant management judgment is required in determining the level of effort required under an arrangement and the period over which we are expected to complete our performance obligations under an arrangement. We may have to revise our estimates based on changes in the expected level of effort or the period we expect to complete our performance obligations.
	Our collaboration agreements may entitle us to additional payments upon the achievement of performance-based milestones. If a milestone involves substantive effort on our part and its achievement is not considered probable at the inception of the collaboration, we recognize the milestone consideration as revenue in the period in which the milestone is achieved only if it meets the following additional criteria:
	•	The milestone consideration received is commensurate with either the level of effort required to achieve the milestone or the enhancement of the value of the item delivered as a result of a specific outcome resulting from our performance to achieve the milestone;
	•	The milestone is related solely to our past performance; and
	•	The milestone consideration is reasonable relative to all deliverables and payment terms in the arrangement.
	There is significant judgment involved in determining whether a milestone meets all of these criteria. For milestones that do not meet the above criteria and are therefore not considered substantive milestones, we recognize that portion of the milestone payment equal to the percentage of the performance period completed at the time the milestone is achieved and the above conditions are met. The remaining portion of the milestone will be recognized over the remaining performance period using a proportional performance or straight-line method.
	Amounts received prior to satisfying the above revenue recognition criteria are recorded as deferred revenue in our consolidated balance sheets. Amounts not expected to be recognized within the next 12 months are classified as long-term deferred revenue.
Research and Development Expenses
	Research and Development Expenses
	Research and development expenses include external expenses, such as costs of clinical trials, contract research and development expenses, certain manufacturing research and development costs, regulatory filing fees, consulting and professional fees and expenses, and internal expenses, such as compensation of employees engaged in research and development activities, the manufacture of product needed to support research and development efforts, related costs of facilities, and other general costs related to research and development. Manufacturing costs are generally expensed as incurred until a product has received the necessary initial regulatory approval.
Advertising Costs
	Advertising Costs
	Advertising costs are expensed as incurred and are included in selling, general and administrative expenses in our consolidated statements of operations. Advertising costs, including promotional expenses and costs related to trade shows were $2.1 million, $1.9 million and $1.8 million for the years ended December 31, 2014, 2013 and 2012, respectively.
Shipping and Handling Costs
	Shipping and Handling Costs
	We utilize two third-party logistics providers, both of which are subsidiaries of one of our distribution customers, to provide us with various shipping and handling services related to sales of our products. As we receive an identifiable benefit and we can reasonably estimate the fair value of this benefit, we have recorded $0.3 million, $0.3 million and $0.2 million as a selling, general and administrative expense during 2014, 2013 and 2012, respectively.
Equity-Based Compensation
	Equity-Based Compensation
	Under the fair value recognition guidance of equity-based compensation accounting rules, equity-based compensation cost is generally required to be measured at the grant date (based upon an estimate of the fair value of the compensation granted) and recorded to expense over the requisite service period, which generally is the vesting period. Because equity-based compensation expense is based on awards ultimately expected to vest, we must make certain judgments about whether employees and directors will complete the requisite service period. Accordingly, we have reduced the compensation expense being recognized for estimated 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. Forfeitures are estimated based upon historical experience and adjusted for unusual events such as corporate restructurings, which can result in higher than expected turnover and forfeitures. If factors change and we employ different forfeiture rate assumptions in future periods, the compensation expense that we record in the future may differ significantly from what we have recorded in the current period.
	We estimate the fair value of equity-based compensation involving stock options based on the Black-Scholes option pricing model. We estimate the fair value of our restricted stock units ("RSUs") whose vesting is contingent upon market conditions using the Monte-Carlo simulation model. These models require the input of several factors such as the expected option term, the expected risk-free interest rate over the expected option term, the expected volatility of our stock price over the expected option term, and the expected dividend yield over the expected option term and are subject to various assumptions. The fair value of awards whose fair values are calculated using the Black-Scholes option pricing model is generally being amortized on a straight-line basis over the requisite service period and is recognized based on the proportionate amount of the requisite service period that has been rendered during each reporting period. The fair value of awards with market conditions is being amortized based upon the estimated derived service period, even if the market condition is never achieved. The fair value of awards with performance conditions is being amortized over the requisite service period if we determine that it is probable that the performance condition will be achieved. We believe our valuation methodologies are appropriate for estimating the fair value of the equity awards we grant to our employees and directors. Our equity award valuations are estimates and thus may not be reflective of actual future results or amounts ultimately realized by recipients of these grants. These amounts, and the amounts applicable to future quarters, are also subject to future quarterly adjustments based upon a variety of factors, which include, but are not limited to, changes in estimated forfeiture rates and the issuance of new equity-based awards. The fair value of service-based RSUs granted to our employees and directors is determined based upon the quoted closing market price per share on the date of grant, adjusted for estimated forfeitures.
Income Taxes
	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 our deferred tax assets will not be realized.
	We account for uncertain tax positions using a "more-likely-than-not" threshold for recognizing and resolving uncertain tax positions. The evaluation of uncertain tax positions is based on factors that include, but are not limited to, changes in tax law, the measurement of tax positions taken or expected to be taken in tax returns, the effective settlement of matters subject to audit, new audit activity and changes in facts or circumstances related to a tax position. We evaluate uncertain tax positions on a quarterly basis and adjust the level of the liability to reflect any subsequent changes in the relevant facts surrounding the uncertain positions. Any changes to these estimates, based on the actual results obtained and/or a change in assumptions, could impact our income tax provision in future periods. Interest and penalty charges, if any, related to unrecognized tax benefits would be classified as a provision for income tax in our consolidated statement of operations.
Concentrations and Significant Customer Information
	Concentrations and Significant Customer Information
	Financial instruments which potentially subject us to concentrations of credit risk consist principally of cash and cash equivalents, investments, and accounts receivable. As of December 31, 2014, our cash, cash equivalents and investments amounted to approximately $144.2 million. We currently invest our excess cash primarily in corporate debt securities. As of December 31, 2014, we had approximately $77.3 million of our total $119.3 million cash and cash equivalents balance invested in institutional money market funds, of which $60.3 million was invested in a single fund.
	Our operations are located solely within the U.S. We are focused principally on developing, manufacturing, and commercializing Makena and 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 2014, 2013 and 2012:
			Years Ended
			December 31,
			2014			2013			2012
	AmerisourceBergen Drug Corporation			34%			41%			34%
	McKesson Corporation			21%			24%			17%
	Cardinal Health, Inc.			15%			16%			12%
	Takeda Pharmaceuticals Company Limited			11%			11%			31%
	In addition, approximately 26%, 30% and 32% of our Feraheme end-user demand in 2014, 2013 and 2012, respectively, was generated by members of a single GPO with which we have contracted. Revenues from customers outside of the U.S. amounted to approximately 12%, 11% and 32% of our total revenues for 2014, 2013 and 2012, respectively, and were principally related to collaboration revenue recognized in connection with the Amended Takeda Agreement with Takeda, which is headquartered in Japan.
	We are currently solely dependent on a single supply chain for Feraheme drug substance and drug product and a single supply chain for Makena drug product. We are exposed to a significant loss of revenue from the sale of Feraheme and Makena if our suppliers and/or manufacturers cannot fulfill demand for any reason.
Comprehensive Income (Loss)
	Comprehensive Income (Loss)
	The current accounting guidance related to comprehensive income (loss) requires us to display comprehensive income (loss) and its components as part of our consolidated financial statements. Our comprehensive income (loss) consists of net income (loss) and other comprehensive income (loss). Other comprehensive income (loss) includes changes in equity that are excluded from net income (loss), which for all periods presented in these financial statements related to unrealized holding gains and losses on available-for-sale investments, net of tax.
Basic and Diluted Net Income ( Loss) per Share
	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 (loss) per common share has been computed by dividing net income (loss) by the diluted number of shares outstanding during the period. Except where the result would be antidilutive to net income (loss), diluted net income (loss) per common share would be computed assuming the impact of the conversion of the $200.0 million of 2.5% convertible senior notes due February 15, 2019 (the "Convertible Notes"), the exercise of outstanding stock options, and the vesting of RSUs.
	We have a choice to settle the conversion obligation under the Convertible Notes in cash, shares or any combination of the two. Pursuant to certain covenants in our Term Loan Facility (as defined in Note S, "Debt" below), which we entered into to partially fund the acquisition of Lumara Health, we may be restricted from settling conversion in whole or in part with cash unless certain conditions in the Term Loan Facility are satisfied, including a first lien leverage ratio. Therefore, after November 12, 2014 we utilized the if-converted method, which assumes the conversion of the Convertible Notes and reflects the elimination of the interest expense recorded from November 12, 2014 through December 31, 2014. 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 weighted average of the closing price of our common stock, over a certain number of days pursuant to the terms of the Convertible Notes, to calculate the number of shares issuable under the conversion premium. In addition, 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 S, "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 were as follows (in thousands, except per share data):
			Years Ended December 31,
			2014			2013			2012
	Net income (loss)		$	135,817		$	(9,602	)	$	(16,750	)
	Weighted average common shares outstanding (basic)			22,416			21,703			21,392
	Effect of dilutive securities (in shares):
	Stock options and restricted stock units			520			—			—
	Convertible 2.5% senior notes			2,289			—			—
	Shares used in calculating dilutive net income (loss) per share			25,225			21,703			21,392
	Net income (loss) per share:
	Basic		$	6.06		$	(0.44	)	$	(0.78	)
	Diluted		$	5.45		$	(0.44	)	$	(0.78	)
	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 (in thousands):
			Years Ended December 31,
			2014			2013			2012
	Options to purchase shares of common stock			2,708			2,820			2,190
	Shares of common stock issuable upon the vesting of restricted stock units			322			465			374
	Warrants			7,382			—			—
	Total			10,412			3,285			2,564
	During 2014, the average common stock price was below the exercise price of the warrants.
Reclassifications
	Reclassifications
	Certain amounts in prior periods have been reclassified in order to conform to the current period presentation.

Summary_of_Significant_Account2

Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2014
Summary of Significant Accounting Policies
Analysis of U.S. product sales allowances and accruals
	An analysis of our U.S. product sales allowances and accruals for the years ended December 31, 2014, 2013 and 2012 is as follows (in thousands):
		Years Ended December 31,
		2014			2013			2012
	Provision for U.S. product sales allowances and accruals
	Discounts and chargebacks	$	55,420		$	37,098		$	26,517
	Government and other rebates		25,091			10,868			6,058
	Medicaid rebate reserve adjustment		—			(568	)		(621	)
	Returns		(1,160	)		952			(1,516	)
	Total provision for U.S. product sales allowances and accruals	$	79,351		$	48,350		$	30,438
	Total gross U.S. product sales	$	188,146		$	119,712		$	88,725
	Total provision for U.S. product sales allowances and accruals as a percent of total gross U.S. product sales		42%			40%			34%
Schedule of customers representing 10% or more of revenues
		Years Ended
		December 31,
		2014			2013			2012
	AmerisourceBergen Drug Corporation		34%			41%			34%
	McKesson Corporation		21%			24%			17%
	Cardinal Health, Inc.		15%			16%			12%
	Takeda Pharmaceuticals Company Limited		11%			11%			31%
Schedule of components of basic and diluted net income (loss) per share
	The components of basic and diluted net income (loss) per share were as follows (in thousands, except per share data):
		Years Ended December 31,
		2014			2013			2012
	Net income (loss)	$	135,817		$	(9,602	)	$	(16,750	)
	Weighted average common shares outstanding (basic)		22,416			21,703			21,392
	Effect of dilutive securities (in shares):
	Stock options and restricted stock units		520			—			—
	Convertible 2.5% senior notes		2,289			—			—
	Shares used in calculating dilutive net income (loss) per share		25,225			21,703			21,392
	Net income (loss) per share:
	Basic	$	6.06		$	(0.44	)	$	(0.78	)
	Diluted	$	5.45		$	(0.44	)	$	(0.78	)
Schedule of anti-dilutive securities excluded from computation of diluted net loss per share
	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 (in thousands):
		Years Ended December 31,
		2014			2013			2012
	Options to purchase shares of common stock		2,708			2,820			2,190
	Shares of common stock issuable upon the vesting of restricted stock units		322			465			374
	Warrants		7,382			—			—
	Total		10,412			3,285			2,564

Business_Combination_Tables

Business Combination (Tables)	12 Months Ended
	Dec. 31, 2014
Lumara Health Inc Member
Summary of the components of the estimated purchase price
	The following table summarizes the components of the estimated total purchase price at fair value, subject to adjustment upon finalization of Lumara Health's net working capital, net debt and transaction expenses as of the Lumara Acquisition Date (in thousands):
		Total Acquisition Date
		Fair Value
	Cash consideration	$	600,000
	Fair value of 3.2 million shares of AMAG common stock		111,964
	Fair value of contingent milestone payments		205,000
	Estimated working capital and other adjustments		821
	Purchase price paid at closing		917,785
	Less:
	Due from sellers		(5,119	)
	Cash acquired from Lumara Health		(5,219	)
	Total purchase price	$	907,447
Summary of estimated fair values of the assets acquired and liabilities assumed related to the business combination
	The following table summarizes the preliminary fair values assigned to the assets acquired and the liabilities assumed by us at the Lumara Acquisition Date (in thousands):
	Accounts receivable	$	34,918
	Inventories		30,300
	Prepaid and other current assets		3,322
	Deferred income tax assets		94,965
	Property and equipment		60
	Makena marketed product		797,100
	IPR&D		79,100
	Restricted cash		1,997
	Other long-term assets		3,412
	Accounts payable		(3,807	)
	Accrued expenses		(41,532	)
	Deferred income tax liabilities		(293,649	)
	Other long-term liabilities		(4,563	)
	Total estimated identifiable net assets		701,623
	Goodwill		205,824
	Total	$	907,447
Pro forma consolidated financial information
	In addition, the pro forma combined net income (loss) in fiscal 2013 does not give effect to the elimination of approximately $392.1 million of non-recurring reorganization gains, net of losses and expenses, realized in connection with Lumara Health's exit from bankruptcy in September 2013 as such amounts are not directly related to the acquisition of Lumara Health (in thousands):
		Year Ended
		December 31,
		2014			2013
	Pro forma combined revenues	$	267,705		$	179,561
	Pro forma combined net income (loss)	$	(23,942	)	$	463,522
PlasmaTech Biopharmaceuticals Inc Member
Summary of the components of the estimated purchase price
	The following table summarizes the total consideration for the MuGard Rights (in thousands):
		Total
		Acquisition
		Date Fair
		Value
	Cash	$	3,434
	Acquisition-related contingent consideration		13,700
	Total consideration	$	17,134
Summary of estimated fair values of the assets acquired and liabilities assumed related to the business combination
	The following table summarizes the fair values of the assets acquired related to the business combination as of the MuGard License Date (in thousands):
	Assets Acquired:
	MuGard intangible asset	$	16,893
	Inventory		241
	Net identifiable assets acquired	$	17,134

Investments_Tables

Investments (Tables)	12 Months Ended
	Dec. 31, 2014
Investments
Summary of investments
	The following is a summary of our investments as of December 31, 2014 and 2013 (in thousands):
		December 31, 2014
		Amortized		Gross		Gross			Estimated
		Cost		Unrealized		Unrealized			Fair
				Gains		Losses			Value
	Corporate debt securities
	Due in one year or less	$	11,656	$	3	$	(4	)	$	11,655
	Due in one to three years		13,258		10		(33	)		13,235
	Total investments	$	24,914	$	13	$	(37	)	$	24,890
		December 31, 2013
		Amortized		Gross		Gross			Estimated
		Cost		Unrealized		Unrealized			Fair
				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)	12 Months Ended
	Dec. 31, 2014
Schedule of assets and liabilities measured at fair value on a recurring basis
	The following tables represent the fair value hierarchy as of December 31, 2014 and 2013, for those assets and liabilities that we measure at fair value on a recurring basis (in thousands):
		Fair Value Measurements at December 31, 2014 Using:
		Total			Quoted Prices in		Significant Other		Significant
					Active Markets for		Observable Inputs		Unobservable
					Identical Assets		(Level 2)		Inputs
					(Level 1)				(Level 3)
	Assets:
	Money market funds	$	77,254		$	77,254	$	—	$	—
	Corporate debt securities		24,890			—		24,890		—
	Total Assets	$	102,144		$	77,254	$	24,890	$	—
	Liabilities:
	Contingent consideration—Lumara Health	$	206,600		$	—	$	—	$	206,600
	Contingent consideration—MuGard		12,102			—		—		12,102
	Total Liabilities	$	218,702		$	—	$	—	$	218,702
		Fair Value Measurements at December 31, 2013 Using:
		Total			Quoted Prices in		Significant Other		Significant
					Active Markets for		Observable Inputs		Unobservable
					Identical Assets		(Level 2)		Inputs
					(Level 1)				(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:
	Contingent consideration—MuGard	$	14,550		$	—	$	—	$	14,550
	Total Liabilities	$	14,550		$	—	$	—	$	14,550
Lumara Health Inc Member
Schedule of reconciliation of contingent consideration obligations related to acquisition measured on recurring basis using Level 3 inputs
	The following table presents a reconciliation of contingent consideration obligations related to the acquisition of Lumara Health measured on a recurring basis using Level 3 inputs as of December 31, 2014 (in thousands):
	Balance as of November 12, 2014	$	—
	Acquisition date fair value of contingent consideration		205,000
	Adjustments to fair value of contingent consideration		1,600
	Balance as of December 31, 2014	$	206,600
PlasmaTech Biopharmaceuticals Inc Member
Schedule of reconciliation of contingent consideration obligations related to acquisition 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 December 31, 2014 and 2013 (in thousands):
	Balance as of June 6, 2013	$	—
	Acquisition date fair value of contingent consideration		13,700
	Payments made		(51	)
	Adjustments to fair value of contingent consideration		1,074
	Other adjustments		(173	)
	Balance as of December 31, 2013	$	14,550
	Payments made		(270	)
	Adjustments to fair value of contingent consideration		(2,281	)
	Other adjustments		103
	Balance as of December 31, 2014	$	12,102

Accounts_Receivable_Net_Tables

Accounts Receivable, Net (Tables)	12 Months Ended
	Dec. 31, 2014
Accounts Receivable, Net
Schedule of customers representing greater than 10% of accounts receivable balances
		December 31,
		2014		2013
	AmerisourceBergen Drug Corporation		45%		43%
	McKesson Corporation		12%		29%
	Cardinal Health, Inc.		<10%		19%

Inventories_Tables

Inventories (Tables)	12 Months Ended
	Dec. 31, 2014
Inventories
Schedule of major classes of inventories
	Our major classes of inventories were as follows as of December 31, 2014 and 2013 (in thousands):
		December 31,
		2014		2013
	Raw materials	$	14,188	$	3,157
	Work in process		5,965		8,322
	Finished goods		20,457		5,738
	Total		40,610		17,217
	Included in other long-term assets:
	Raw materials		7,798		—
	Total inventories	$	48,408	$	17,217

Property_and_Equipment_Net_Tab

Property and Equipment, Net (Tables)	12 Months Ended
	Dec. 31, 2014
Property and Equipment, Net
Schedule of property and equipment
	Property and equipment consisted of the following as of December 31, 2014 and 2013 respectively (in thousands):
		December 31,
		2014			2013
	Furniture and fixtures	$	1,574		$	1,536
	Leasehold improvements		430			430
	Laboratory and production equipment		493			376
			2,497			2,342
	Less—accumulated depreciation		(978	)		(496	)
	Property and equipment, net	$	1,519		$	1,846

Goodwill_and_Intangible_Assets1

Goodwill and Intangible Assets, Net (Tables)	12 Months Ended
	Dec. 31, 2014
Goodwill and Intangible Assets, Net
Schedule of identifiable intangible assets
	As of December 31, 2014 and 2013, our identifiable intangible assets consisted of the following (in thousands):
		December 31, 2014						December 31, 2013
		Cost		Accumulated		Net		Cost		Accumulated		Net
				Amortization						Amortization
	Amortizable intangible assets:
	Makena Marketed Product	$	797,100	$	4,834	$	792,266	$	—	$	—	$	—
	MuGard Rights		16,893		351		16,542		16,893		49		16,844
			813,993		5,185		808,808		16,893		49		16,844
	Indefinite-lived intangible assets:
	IPR&D		79,100		—		79,100		—		—		—
	Total intangible assets	$	893,093	$	5,185	$	887,908	$	16,893	$	49	$	16,844
Schedule of expected future annual amortization expense related to intangible asset
	We expect amortization expense related to our finite-lived intangible assets for the next five fiscal years to be as follows (in thousands):
	Period	Estimated
		Amortization
		Expense
	Year Ended December 31, 2015		51,886
	Year Ended December 31, 2016		64,977
	Year Ended December 31, 2017		76,679
	Year Ended December 31, 2018		84,359
	Year Ended December 31, 2019		55,746
	Total	$	333,647

Current_and_LongTerm_Liabiliti

Current and Long-Term Liabilities (Tables)	12 Months Ended
	Dec. 31, 2014
Current and Long-Term Liabilities
Schedule of accrued expenses
	Accrued expenses consisted of the following as of December 31, 2014 and 2013 (in thousands):
		December 31,
		2014		2013
	Commercial rebates, fees and returns	$	44,807	$	4,839
	Professional, license, and other fees and expenses		14,888		1,932
	Salaries, bonuses, and other compensation		10,176		5,419
	Clinical, manufacturing and regulatory consulting fees and expenses		7,181		7,834
	Restructuring expense		1,952		—
	Commercial consulting fees and expenses		1,089		1,301
	Short-term contingent consideration		718		941
	Total accrued expenses	$	80,811	$	22,266
Schedule of deferred revenues
	Deferred revenues consisted of the following as of December 31, 2014 and 2013 (in thousands):
		December 31,
		2014		2013
	Short-term deferred revenues:
	Takeda	$	44,376	$	8,226
	Total	$	44,376	$	8,226
	Long-term deferred revenues:
	Takeda	$	—	$	43,534
	3SBio		—		1,000
	Total	$	—	$	44,534

Income_Taxes_Tables

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2014
Income Taxes
Schedule of components of the entity's deferred tax assets and liabilities
	The income tax benefit consisted of the following (in thousands):
		Years Ended December 31,
		2014			2013			2012
	Current:
	Federal	$	—		$	—		$	—
	State		—			—			—
	Total current	$	—		$	—		$	—
	Deferred:
	Federal	$	(142,884	)	$	—		$	(833	)
	State		(10,275	)		—			(21	)
	Total deferred	$	(153,159	)	$	—		$	(854	)
	Total income tax benefit	$	(153,159	)	$	—		$	(854	)
		Years Ended December 31,
		2014			2013			2012
	Statutory U.S. federal tax rate		-34.00%			-34.00%			-34.00%
	State taxes, net of federal benefit		-7.90%			2.4%			4.2%
	Equity-based compensation expense		10.6%			9.4%			42.4%
	Permanent items, net		16.0%			5.3%			1.2%
	Tax credits		-3.00%			0.5%			0.8%
	Valuation allowance		-864.90%			16.4%			-19.50%
	Total tax benefit		-883.20%			0.0%			-4.90%
Schedule of reconciliation of the statutory U.S. federal income tax rate to the entity's effective income tax rate
	The components of our deferred tax assets and liabilities are as follows (in thousands):
		December 31,
		2014			2013
	Assets
	Net operating loss carryforwards	$	188,873		$	85,269
	Tax credit carryforwards		24,574			12,396
	Deferred revenue		17,216			20,368
	Equity-based compensation expense		3,436			4,176
	Capitalized research & development		32,359			39,214
	Intangibles		272			680
	Debt instruments		731			—
	Reserves		7,782			—
	Property, plant and equipment		61			—
	Other		5,014			4,371
	Liabilities
	Property, Plant, and Equipment Depreciation		—			(58	)
	Intangible Assets and Inventory Amortization		(290,491	)		—
	Other		(1,795	)		—
			(11,968	)		166,416
	Valuation allowance		(33,557	)		(166,416	)
	Net deferred taxes	$	(45,525	)	$	—

Accumulated_Other_Comprehensiv1

Accumulated Other Comprehensive (Loss) (Tables)	12 Months Ended
	Dec. 31, 2014
Accumulated Other Comprehensive Loss
Schedule of changes in accumulated other comprehensive loss, net of tax
	The table below presents information about the effects of net income (loss) of significant amounts reclassified out of accumulated other comprehensive loss ("AOCI"), net of tax, during 2014 and 2013 (in thousands):
		December 31,
		2014			2013
	Beginning Balance	$	(3,491	)	$	(3,247	)
	Other comprehensive income (loss) before reclassifications		(191	)		(268	)
	Gain (loss) reclassified from other accumulated comprehensive loss		65			24
	Ending Balance	$	(3,617	)	$	(3,491	)

EquityBased_Compensation_Table

Equity-Based Compensation (Tables)	12 Months Ended
	Dec. 31, 2014
Equity-Based Compensation
Schedule of equity-based compensation expense
	Equity-based compensation expense for 2014, 2013 and 2012 consisted of the following (in thousands):
		Years Ended December 31,
		2014			2013		2012
	Cost of product sales	$	122		$	121	$	225
	Research and development		1,596			2,149		1,994
	Selling, general and administrative		6,907			5,734		4,805
	Total equity-based compensation expense	$	8,625		$	8,004	$	7,024
Summary of weighted average assumptions used for valuing option awards granted
		Years Ended December 31,
		2014					2013				2012
		Employees			Non-Employee		Employees		Non-Employee		Employees		Non-Employee
					Directors				Directors				Directors
	Risk free interest rate (%)		1.56			1.28		0.95		0.85		0.66		0.68
	Expected volatility (%)		47			46		59		46		57		56
	Expected option term (years)		5.00			4.00		5.00		4.00		4.66		4.00
	Dividend yield		none			none		none		none		none		none
Summary of details regarding stock options granted under equity incentive plans
		December 31, 2014
		Options			Weighted		Weighted		Aggregate
					Average		Average		Intrinsic Value
					Exercise Price		Remaining		($ in millions)
							Contractual
							Term
	Outstanding at beginning of year		2,819,676		$	21.31
	Granted		1,391,776			25.75
	Exercised		(494,576	)		19.43
	Expired and/or forfeited		(720,493	)		25.81
	Outstanding at end of year		2,996,383		$	22.6		7.7	$	60,546
	Outstanding at end of year—vested and unvested expected to vest		2,688,944		$	22.6		7.6	$	54,410
	Exercisable at end of year		946,787		$	22.47		6	$	60,459
Summary of details regarding restricted stock units granted under equity incentive plans
		December 31, 2014
		Unvested			Weighted
		Restricted			Average Grant
		Stock Units			Date Fair Value
	Outstanding at beginning of year		465,394		$	17.28
	Granted		356,626			22.88
	Vested		(151,518	)		17.71
	Forfeited		(129,276	)		18.25
	Outstanding at end of year		541,226		$	20.62
	Outstanding at end of year and expected to vest		465,686		$	20.59

Commitments_and_Contingencies_

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2014
Commitments and Contingencies
Schedule of future minimum rent payments
	Future minimum payments under our non-cancelable facility-related leases as of December 31, 2014 are as follows (in thousands):
	Period	Minimum Lease
		Payments
	Year Ended December 31, 2015	$	1,451
	Year Ended December 31, 2016		1,456
	Year Ended December 31, 2017		1,462
	Year Ended December 31, 2018		1,174
	Total	$	5,543

Debt_Tables

Debt (Tables)	12 Months Ended
	Dec. 31, 2014
Debt
Schedule of outstanding convertible note balances
	Our outstanding Convertible Note balances as December 31, 2014 consisted of the following (in thousands):
		December 31, 2014
	Liability component:
	Principal	$	200,000
	Less: debt discount, net		(32,559	)
	Net carrying amount	$	167,441
	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 year ended December 31, 2014 (in thousands):
		Year Ended
		December 31, 2014
	Contractual interest expense	$	4,375
	Amortization of debt issuance costs		800
	Amortization of debt discount		5,629
	Total interest expense	$	10,804
Schedule of Future annual principal payments on long-term debt
	Future annual principal payments on our long-term debt as of December 31, 2014 were as follows:
	2015	$	34,000
	2016		51,000
	2017		51,000
	2018		51,000
	2019		51,000
	Thereafter		102,000
	Total	$	340,000

Restructuring_Tables

Restructuring (Tables)	12 Months Ended
	Dec. 31, 2014
Restructuring
Schedule of components of restructuring expenses and current liabilities
	The following table outlines the components of our restructuring expenses which were included in current liabilities for 2014 (in thousands):
		December 31, 2014
	Accrued restructuring, beginning of period	$	—
	Employee severance, benefits and related costs		2,023
	Payments		(70	)
	Accrued restructuring, end of period	$	1,953

Consolidated_Quarterly_Financi1

Consolidated Quarterly Financial Data-Unaudited (Tables)	12 Months Ended
	Dec. 31, 2014
Consolidated Quarterly Financial Data-Unaudited
Schedule of unaudited consolidated quarterly financial data
	The following tables provide unaudited consolidated quarterly financial data for 2014 and 2013 (in thousands, except per share data):
		March 31, 2014			June 30, 2014			September 30, 2014			December 31, 2014
	U.S. product sales, net	$	17,375		$	22,225		$	22,547		$	46,648
	License fee and other collaboration revenues		3,120			2,122			2,182			3,462
	Other product sales and royalties		340			455			765			3143
	Total revenues		20,835			24,802			25,494			53,253
	Cost of product sales		2,837			2,743			2,968			11,758
	Gross margin		17,998			22,059			22,526			41,495
	Operating expenses		23,989			20,824			18,233			44,869
	Interest expense		(1,476	)		(3,051	)		(3,129	)		(7,041	)
	Interest and dividend income, net		265			253			291			166
	Gains on sale of assets		100			2			—			1
	Gains on investments, net		—			14			3			97
	Net income (loss) before income taxes		(7,102	)		(1,547	)		1,458			(10,151	)
	Income tax benefit		—			—			—			153,159
	Net income (loss)	$	(7,102	)	$	(1,547	)	$	1,458		$	143,008
	Net income (loss) per share—basic	$	(0.33	)	$	(0.07	)	$	0.07		$	5.98
	Net income (loss) per share—diluted	$	(0.33	)	$	(0.07	)	$	0.07		$	4.67
		March 31, 2013			June 30, 2013			September 30, 2013			December 31, 2013
	U.S. Feraheme product sales, net	$	15,578		$	17,456		$	19,347		$	18,981
	License fee and other collaboration revenues		2,003			2,055			1,998			2,329
	Other product sales and royalties		299			138			271			401
	Total revenues		17,880			19,649			21,616			21,711
	Cost of product sales		2,942			3,145			2,547			3,326
	Gross margin		14,938			16,504			19,069			18,385
	Operating expenses		19,409			19,260			19,464			22,380
	Interest and dividend income, net		271			256			246			278
	Gains on assets held for sale		299			566			—			59
	Gains on investments, net		6			26			4			4
	Net loss	$	(3,895	)	$	(1,908	)	$	(145	)	$	(3,654	)
	Net loss per share—basic and diluted	$	(0.18	)	$	(0.09	)	$	(0.01	)	$	(0.17	)

Valuation_and_Qualifying_Accou1

Valuation and Qualifying Accounts (Tables)	12 Months Ended
	Dec. 31, 2014
Valuation and Qualifying Accounts
Schedule of valuation and qualifying accounts
			Balance at		Additions(a)		Deductions			Balance at
			Beginning				Charged to			End of
			of Period				Reserves			Period
	Year ended December 31, 2014:
	Accounts receivable allowances(b)		$	2,683	$	59,372	$	(50,580	)	$	11,475
	Rebates, fees and returns reserves		$	4,799	$	52,079	$	(13,126	)	$	43,752
	Year ended December 31, 2013:
	Accounts receivable allowances(b)		$	1,771	$	37,098	$	(36,186	)	$	5,850
	Rebates, fees and returns reserves		$	3,448	$	11,820	$	(10,469	)	$	4,799
	Year ended December 31, 2012:
	Accounts receivable allowances(b)		$	1,822	$	26,517	$	(26,568	)	$	1,771
	Rebates, fees and returns reserves		$	5,943	$	6,729	$	(9,224	)	$	3,448
	(a)	Additions to sales discounts, rebates, fees and returns reserves are recorded as a reduction of revenues.
	(b)	We have not recorded an allowance for doubtful accounts in any of the years presented above. These accounts receivable allowances represent discounts and other chargebacks related to the provision for our product sales.

Description_of_Business_Detail

Description of Business (Details) (USD $)	12 Months Ended	0 Months Ended
Share data in Thousands, unless otherwise specified	Dec. 31, 2014	Nov. 12, 2014
Business Acquisition [Line Items]
Fair value of common stock issued in connection with the Lumara Health acquisition	$111,964,000
Lumara Health Inc Member
Business Acquisition [Line Items]
Amount of consideration paid in cash		600,000,000
Net shares issued in connection with the acquisition of Lumara Health (in shares)		3,200
Fair value of common stock issued in connection with the Lumara Health acquisition		112,000,000
Future contingent payments, maximum		$350,000,000

Summary_of_Significant_Account3

Summary of Significant Accounting Policies (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
Total restricted cash	$2,400,000	$3,300,000
Escrow payment related to business development transaction		2,883,000
Security deposit in the form of an irrevocable letter of credit	400,000	400,000
Lumara Health Inc Member
Total restricted cash	$2,000,000

Summary_of_Significant_Account4

Summary of Significant Accounting Policies (Details 2) (USD $)	3 Months Ended		12 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Provision for U.S. product sales allowances and accruals
Discounts and chargebacks			$55,420	$37,098	$26,517
Government and other rebates			25,091	10,868	6,058
Medicaid rebate reserve adjustment	23,200	23,200		-568	-621
Returns			-1,160	952	-1,516
Total provision for U.S product sales allowances and accruals			79,351	48,350	30,438
Total gross U.S. product sales			$188,146	$119,712	$88,725
Total provision for product sales allowances and accruals as a percent of total gross product sales			42.00%	40.00%	34.00%
Typical average period from time of product sale to payment of rebate, up to or longer than			3 months
Discounts
Percentage of prompt payment discount to customers			2.00%
Period within which discount is offered to customers for prompt payment			30 days
Accrued percentage of the prompt payment discount			100.00%
Laboratory and Production Equipment [Member]
Property and Equipment
Estimated useful lives			5 years
Furniture and Fixtures [Member]
Property and Equipment
Estimated useful lives			5 years

Summary_of_Significant_Account5

Summary of Significant Accounting Policies (Details 3) (USD $)	3 Months Ended	12 Months Ended
In Millions, except Per Share data, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Product Returns
Reduction of reserve for product returns	$0.30	$1.80		$2.20
Reduction of product return reserve impact on earnings per share basic (in dollars per share)		$0.12		$0.10
Reduction of product return reserve impact on earnings per share diluted (in dollars per share)		$0.14		$0.10
Advertising Costs
Advertising costs, including promotional expenses and costs related to trade shows		2.1	1.9	1.8
Shipping and Handling Costs
Costs for shipping and handling services		0.3	0.3	0.2
Government and Other Rebates
Reduction in Medicaid rebate reserves			$0.60	$0.60
Reduction in estimated Medicaid rebate reserve, impact per basic and diluted share (in dollars per share)			$0.03	$0.03
Distributor/Wholesaler and Group Purchasing Organization Fees [Abstract]
Period within which fees are billed by the GPO		30 days
U.S. Feraheme
Product Returns
Expiration period for products		5 years
Makena
Product Returns
Expiration period for products		3 years
MuGard
Product Returns
Expiration period for products		3 years

Summary_of_Significant_Account6

Summary of Significant Accounting Policies (Details 4) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Investment Concentration Risk
Cash, cash equivalents and investments	144,200,000
Investment in institutional money market funds	77,300,000
Cash and cash equivalents	119,296,000	26,986,000	46,293,000	63,474,000
Amount invested in a single fund	60,300,000
Minimum [Member]
Customers representing 10% or more of revenues
Percentage of revenues from major customer	10.00%
Amerisource Bergen Drug Corporation [Member]
Customers representing 10% or more of revenues
Percentage of revenues from major customer	45.00%	43.00%
McKesson Corporation [Member]
Customers representing 10% or more of revenues
Percentage of revenues from major customer	12.00%	29.00%
Cardinal Health Inc [Member]
Customers representing 10% or more of revenues
Percentage of revenues from major customer		19.00%
Cardinal Health Inc [Member] | Maximum
Customers representing 10% or more of revenues
Percentage of revenues from major customer	10.00%
Sales Revenue, Net [Member] | Customer Concentration Risk [Member] | Amerisource Bergen Drug Corporation [Member]
Customers representing 10% or more of revenues
Percentage of revenues from major customer	34.00%	41.00%	34.00%
Sales Revenue, Net [Member] | Customer Concentration Risk [Member] | McKesson Corporation [Member]
Customers representing 10% or more of revenues
Percentage of revenues from major customer	21.00%	24.00%	17.00%
Sales Revenue, Net [Member] | Customer Concentration Risk [Member] | Cardinal Health Inc [Member]
Customers representing 10% or more of revenues
Percentage of revenues from major customer	15.00%	16.00%	12.00%
Sales Revenue, Net [Member] | Customer Concentration Risk [Member] | Takeda Pharmaceutical Company Limited [Member]
Customers representing 10% or more of revenues
Percentage of revenues from major customer	11.00%	11.00%	31.00%
Sales Revenue, Net [Member] | Customer Concentration Risk [Member] | Group Purchasing Organization [Member]
Customers representing 10% or more of revenues
Percentage of revenues from major customer	26.00%	30.00%	32.00%
Sales Revenue, Net [Member] | Geographic Concentration Risk [Member]
Percentage of revenues From customers outside of the U.S.
Approximate percentage of revenues from customers outside the U.S.	12.00%	11.00%	32.00%

Summary_of_Significant_Account7

Summary of Significant Accounting Policies (Details 5) (USD $)	3 Months Ended								12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Summary of Significant Accounting Policies
Net income (loss)	$143,008	$1,458	($1,547)	($7,102)	($3,654)	($145)	($1,908)	($3,895)	$135,817	($9,602)	($16,750)
Weighted average common shares outstanding (basic)									22,416	21,703	21,392
Stock options and restricted stock units (in shares)									520
Convertible 2.5% senior notes									2,289
Shares used in calculating dilutive net income (loss) per share (in shares)									25,225	21,703	21,392
Anti-dilutive securities excluded from the computation of diluted net income (loss) per share
Anti-dilutive securities (in shares)									10,412	3,285	2,564
Net income (loss) per share:
Basic	$5.98	$0.07	($0.07)	($0.33)					$6.06	($0.44)	($0.78)
Diluted	$4.67	$0.07	($0.07)	($0.33)					$5.45	($0.44)	($0.78)
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)									2,708	2,820	2,190
Restricted Stock Units (RSUs) [Member]
Anti-dilutive securities excluded from the computation of diluted net income (loss) per share
Anti-dilutive securities (in shares)									322	465	374
Warrants
Anti-dilutive securities excluded from the computation of diluted net income (loss) per share
Anti-dilutive securities (in shares)									7,382

Business_Combination_Details

Business Combination (Details) (USD $)	3 Months Ended								12 Months Ended			0 Months Ended	1 Months Ended	2 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Nov. 12, 2014	Sep. 30, 2013	Dec. 31, 2014
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net [Abstract]
Inventories												$30,300,000
Goodwill	205,824,000								205,824,000					205,824,000
Cost of product sales	11,758,000	2,968,000	2,743,000	2,837,000	3,326,000	2,547,000	3,145,000	2,942,000	20,306,000	11,960,000	14,220,000
U.S. product sales, net	46,648,000	22,547,000	22,225,000	17,375,000	18,981,000	19,347,000	17,456,000	15,578,000	108,795,000	71,362,000	58,287,000
Fair Value Inputs [Abstract]
Acquisition-related contingent consideration	205,000,000				13,700,000				205,000,000	13,700,000				205,000,000
Acquisition-related costs									9,478,000	782,000
Business Acquisition, Pro Forma Information [Abstract]
Income tax benefit	-153,159,000								-153,159,000		-854,000
Fair Value Adjustment to Inventory [Member]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net [Abstract]
Inventories												26,100,000
Amount recognized in current period									1,300,000
Balance	24,800,000								24,800,000					24,800,000
2015									11,100,000
2016									3,500,000
2017									4,000,000
2018									3,500,000
2019									2,700,000
Lumara Health
Business Acquisition [Line Items]
Ownership percentage acquired												100.00%
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net [Abstract]
Accounts receivable												34,918,000
Inventories												30,300,000
Prepaid and other current assets												3,322,000
Deferred income taxes												94,965,000
Property and equipment												60,000
Makena marketed product												797,100,000
IPR & D												79,100,000
Restricted cash												1,997,000
Other long-term assets												3,412,000
Accounts payable												-3,807,000
Accrued expenses												-41,532,000
Deferred income tax liabilities												-293,649,000
Other long-term liabilities												-4,563,000
Total estimated identifiable net assets												701,623,000
Goodwill												205,824,000
Total												907,447,000
Gross accounts receivable												40,500,000
Balance	24,800,000								24,800,000					24,800,000
U.S. product sales, net														22,500,000
Fair Value Inputs [Abstract]
Discount rate (as a percent)												5.00%
Acquisition-related contingent consideration												205,000,000
Deferred tax assets acquired												94,965,000
Acquisition-related costs									9,500,000
Business Acquisition, Pro Forma Information [Abstract]
Gain upon exit from reorganization													385,900,000
Pro forma combined revenues									267,705,000	179,561,000
Pro forma combined net income (loss)									-23,942,000	463,522,000
Lumara Health | Fair Value Adjustment to Inventory [Member]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net [Abstract]
Inventories												26,100,000
Amount recognized in current period									1,300,000
2015									11,100,000
2016									3,500,000
2017									4,000,000
2018									3,500,000
2019									$2,700,000

Business_Combination_Details_2

Business Combination (Details 2) (USD $)	12 Months Ended	0 Months Ended
Share data in Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2014	Nov. 12, 2014	Nov. 11, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Business Acquisition [Line Items]
Common stock, par value (in dollars per share)	$0.01			$0.01
Fair value of 3.2 million shares of AMAG common stock	$111,964,000
Fair value of contingent milestone payments	205,000,000			13,700,000
Proceeds from term loan	327,509,000
Cash on hand	119,296,000			26,986,000	46,293,000	63,474,000
Share price (in dollars per share)			$34.88
Lumara Health
Business Acquisition [Line Items]
Undiscounted milestone amounts to be paid, high range		350,000,000
Cash consideration		600,000,000
Fair value of 3.2 million shares of AMAG common stock		111,964,000
Fair value of contingent milestone payments		205,000,000
Estimated working capital and other adjustments		821,000
Purchase price paid at closing		917,785,000
Due from sellers		-5,119,000
Cash acquired from Lumara Health		-5,219,000
Total purchase price paid		907,447,000
Shares of AMAG common stock issued in business combination		3,200
Cash on hand		272,500,000
Business Combination, Contingent Consideration Arrangements [Abstract]
Future contingent payments, maximum		350,000,000
First Milestone | Lumara Health
Business Combination, Contingent Consideration Arrangements [Abstract]
Milestone payment to be paid by company upon milestone achievement	100,000,000
Aggregate net sales milestone	300,000,000
Consectuive time period for achievement of milestone	12 months
Second Milestone | Lumara Health
Business Combination, Contingent Consideration Arrangements [Abstract]
Milestone payment to be paid by company upon milestone achievement	100,000,000
Aggregate net sales milestone	400,000,000
Consectuive time period for achievement of milestone	12 months
Setoff amount upon which milestone payment is subject to under certain conditions	50,000,000
Third Milestone | Lumara Health
Business Combination, Contingent Consideration Arrangements [Abstract]
Milestone payment to be paid by company upon milestone achievement	50,000,000
Aggregate net sales milestone	700,000,000
Consectuive time period for achievement of milestone	24 months
Setoff amount upon which milestone payment is subject to under certain conditions	100,000,000
Month after Second Milestone | Lumara Health
Business Combination, Contingent Consideration Arrangements [Abstract]
Milestone payment to be paid by company upon milestone achievement	100,000,000
Aggregate net sales milestone	500,000,000
Consectuive time period for achievement of milestone	12 months
Milestones during the calendar years of 2015 through 2019 | Lumara Health
Business Combination, Contingent Consideration Arrangements [Abstract]
Milestone payment to be paid by company upon milestone achievement	50,000,000
Aggregate net sales milestone	200,000,000
Consectuive time period for achievement of milestone	5 years
Lumara Security Holders Escrow Fund | Lumara Health
Business Acquisition [Line Items]
Escrow fund		7,000,000
Business Combination, Contingent Consideration Arrangements [Abstract]
Maximum amount of contingent payments due in any calendar year	100,000,000
Indemnification Escrow Fund | Lumara Health
Business Acquisition [Line Items]
Escrow fund		35,000,000
Term Loan | Lumara Health
Business Acquisition [Line Items]
Proceeds from term loan		327,500,000
Principal amount of debt issued		340,000,000
Common Stock
Business Acquisition [Line Items]
Fair value of 3.2 million shares of AMAG common stock	$32,000
Shares of AMAG common stock issued in business combination	3,210
Common Stock | Lumara Health
Business Acquisition [Line Items]
Common stock, par value (in dollars per share)		$0.01

Business_Combination_Details_3

Business Combination (Details 3) (USD $)	12 Months Ended		0 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Jun. 06, 2013	Nov. 12, 2014	Jun. 30, 2013
Consideration:
Acquisition-related contingent consideration	$205,000,000	$13,700,000
Assets Acquired
Inventories				30,300,000
Acquisition-related costs	9,478,000	782,000
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Fair value inputs
Discount rate (as a percent)		15.00%
PlasmaTech Biopharmaceuticals Inc Member
Consideration:
Acquisition-related contingent consideration		13,700,000
Assets Acquired
Acquired finite-lived intangible assets	16,900,000
PlasmaTech Biopharmaceuticals Inc Member | Fair Value, Inputs, Level 3 [Member]
Fair value inputs
Discount rate (as a percent)	15.00%
PlasmaTech Biopharmaceuticals Inc Member | Licensing Agreements [Member]
Business Acquisition [Line Items]
Upfront payment in consideration of license			3,300,000
Consideration:
Cash consideration			3,434,000
Acquisition-related contingent consideration			13,700,000
Total purchase price paid			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
Inventories			241,000		200,000
Total assets acquired			17,134,000
Acquisition-related costs		800,000
PlasmaTech Biopharmaceuticals Inc Member | Licensing Agreements [Member] | Fair Value, Inputs, Level 3 [Member]
Fair value inputs
Discount rate (as a percent)	19.00%
PlasmaTech Biopharmaceuticals Inc Member | Licensing Agreements [Member] | Minimum [Member]
Fair value inputs
Estimated undiscounted royalty amounts payable	20,000,000	20,000,000
PlasmaTech Biopharmaceuticals Inc Member | Licensing Agreements [Member] | Maximum
Fair value inputs
Estimated undiscounted royalty amounts payable	$28,000,000	$28,000,000

Investments_Details

Investments (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Summary of Investments
Total investments	$24,914	$186,701
Available-for-sale securities, Gross Unrealized Gains	13	237
Available-for-sale securities, Gross Unrealized Losses	-37	-135
Available-for-sale securities, Estimated Fair Value	24,890	186,803
Proceeds from Sale and Maturity of Available-for-sale Securities	223,568	106,030	133,061
Lumara Health
Summary of Investments
Proceeds from Sale and Maturity of Available-for-sale Securities	170,400
Corporate Debt Securities [Member]
Summary of Investments
Available-for-sale securities due in one year or less, Amortized Cost	11,656	42,609
Available-for-sale securities due in one to three years, Amortized Cost	13,258	91,443
Available-for-sale securities due in one year or less, Gross Unrealized Gains	3	44
Available-for-sale securities due in one to three years, Gross Unrealized Gains	10	137
Available-for-sale securities due in one year or less, Gross Unrealized Losses	-4	-4
Available-for-sale securities due in one to three years, Gross Unrealized Losses	-33	-106
Available-for-sale securities due in one year or less, Estimated Fair Value	11,655	42,649
Available-for-sale securities due in one to three years, Estimated Fair Value	13,235	91,474
US Treasury and Government [Member]
Summary of Investments
Available-for-sale securities due in one year or less, Amortized Cost		18,526
Available-for-sale securities due in one to three years, Amortized Cost		34,123
Available-for-sale securities due in one year or less, Gross Unrealized Gains		19
Available-for-sale securities due in one to three years, Gross Unrealized Gains		37
Available-for-sale securities due in one to three years, Gross Unrealized Losses		-25
Available-for-sale securities due in one year or less, Estimated Fair Value		18,545
Available-for-sale securities due in one to three years, Estimated Fair Value		$34,135

Investments_Details_2

Investments (Details 2) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2012
Realized Gains and Losses on Investments
Realized gains	$0.10
Realized losses		$1.50

Fair_Value_Measurements_Detail

Fair Value Measurements (Details) (Fair Value, Measurements, Recurring [Member], USD $)	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2014
In Thousands, unless otherwise specified
Fair value of assets and liabilities measured on a recurring basis
Total Liabilities	$14,550
Transfers or reclassifications of securities from Level 1 to Level 2	0	0
Transfers or reclassifications of securities from Level 2 to Level 1	0	0
Acquisition Related Contingent Consideration [Member]
Fair value of assets and liabilities measured on a recurring basis
Total Liabilities	14,550
Estimate of Fair Value Measurement [Member]
Fair value of assets and liabilities measured on a recurring basis
Total Assets	205,570		102,144
Total Liabilities	14,550		218,702
Estimate of Fair Value Measurement [Member] | PlasmaTech Biopharmaceuticals Inc Member
Fair value of assets and liabilities measured on a recurring basis
Total Liabilities			12,102
Estimate of Fair Value Measurement [Member] | Acquisition Related Contingent Consideration [Member]
Fair value of assets and liabilities measured on a recurring basis
Total Liabilities	14,550
Estimate of Fair Value Measurement [Member] | Acquisition Related Contingent Consideration [Member] | Lumara Health Inc Member
Fair value of assets and liabilities measured on a recurring basis
Total Liabilities			206,600
Estimate of Fair Value Measurement [Member] | Money Market Funds [Member]
Fair value of assets and liabilities measured on a recurring basis
Total Assets	18,767		77,254
Estimate of Fair Value Measurement [Member] | Corporate Debt Securities [Member]
Fair value of assets and liabilities measured on a recurring basis
Total Assets	134,123		24,890
Estimate of Fair Value Measurement [Member] | US Treasury and Government [Member]
Fair value of assets and liabilities measured on a recurring basis
Total Assets	52,680
Fair Value, Inputs, Level 1 [Member]
Fair value of assets and liabilities measured on a recurring basis
Total Assets	18,767		77,254
Fair Value, Inputs, Level 1 [Member] | Money Market Funds [Member]
Fair value of assets and liabilities measured on a recurring basis
Total Assets	18,767		77,254
Fair Value, Inputs, Level 2 [Member]
Fair value of assets and liabilities measured on a recurring basis
Total Assets	186,803		24,890
Fair Value, Inputs, Level 2 [Member] | Corporate Debt Securities [Member]
Fair value of assets and liabilities measured on a recurring basis
Total Assets	134,123		24,890
Fair Value, Inputs, Level 2 [Member] | US Treasury and Government [Member]
Fair value of assets and liabilities measured on a recurring basis
Total Assets	52,680
Fair Value, Inputs, Level 3 [Member]
Fair value of assets and liabilities measured on a recurring basis
Total Liabilities			218,702
Fair Value, Inputs, Level 3 [Member] | PlasmaTech Biopharmaceuticals Inc Member
Fair value of assets and liabilities measured on a recurring basis
Total Liabilities			12,102
Fair Value, Inputs, Level 3 [Member] | Acquisition Related Contingent Consideration [Member] | Lumara Health Inc Member
Fair value of assets and liabilities measured on a recurring basis
Total Liabilities			$206,600

Fair_Value_Measurements_Detail1

Fair Value Measurements (Details 2) (USD $)	12 Months Ended		7 Months Ended	2 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2013	Dec. 31, 2014	Feb. 14, 2014	Jun. 06, 2013	Nov. 12, 2014
Reconciliation of contingent consideration obligations related to acquisition rights
Acquisition-related contingent consideration	$205,000,000	$13,700,000	$13,700,000	$205,000,000
Adjustments to fair value of contingent consideration	-681,000	1,074,000
Contingent consideration classified as short term liability	718,000	941,000	941,000	718,000
Interest rate (as a percent)	2.50%	2.50%	2.50%	2.50%
Estimated fair value of the Notes	332,000,000			332,000,000
Convertible Debt [Member]
Reconciliation of contingent consideration obligations related to acquisition rights
Aggregate principal amount of notes issued	200,000,000			200,000,000	200,000,000
Interest rate (as a percent)	2.50%			2.50%
Fair Value, Inputs, Level 2 [Member] | Convertible Debt [Member]
Reconciliation of contingent consideration obligations related to acquisition rights
Estimated fair value of the Notes	332,000,000			332,000,000
Fair Value, Inputs, Level 2 [Member] | Term Loan
Reconciliation of contingent consideration obligations related to acquisition rights
Estimated fair value of the Notes	342,000,000			342,000,000
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Reconciliation of contingent consideration obligations related to acquisition rights
Discount rate (as a percent)		15.00%
PlasmaTech Biopharmaceuticals Inc Member
Reconciliation of contingent consideration obligations related to acquisition rights
Balance at beginning of period	14,550,000
Acquisition-related contingent consideration		13,700,000	13,700,000
Payments made	-270,000		-51,000
Adjustments to fair value of contingent consideration	-2,281,000		1,074,000
Other adjustments	103,000		-173,000
Balance at end of period	12,102,000	14,550,000	14,550,000	12,102,000
Acquired finite-lived intangible assets	16,900,000			16,900,000
PlasmaTech Biopharmaceuticals Inc Member | Fair Value, Inputs, Level 3 [Member]
Reconciliation of contingent consideration obligations related to acquisition rights
Discount rate (as a percent)	15.00%
PlasmaTech Biopharmaceuticals Inc Member | Licensing Agreements [Member]
Reconciliation of contingent consideration obligations related to acquisition rights
Acquisition-related contingent consideration						13,700,000
Period over which estimated undiscounted royalty amounts could be paid	10 years
Acquired finite-lived intangible assets						16,893,000
Contingent consideration classified as short term liability	800,000			800,000
PlasmaTech Biopharmaceuticals Inc Member | Licensing Agreements [Member] | Fair Value, Inputs, Level 3 [Member]
Reconciliation of contingent consideration obligations related to acquisition rights
Discount rate (as a percent)	19.00%
PlasmaTech Biopharmaceuticals Inc Member | Licensing Agreements [Member] | Minimum [Member]
Reconciliation of contingent consideration obligations related to acquisition rights
Estimated undiscounted royalty amounts payable	20,000,000	20,000,000	20,000,000	20,000,000
PlasmaTech Biopharmaceuticals Inc Member | Licensing Agreements [Member] | Maximum
Reconciliation of contingent consideration obligations related to acquisition rights
Estimated undiscounted royalty amounts payable	28,000,000	28,000,000	28,000,000	28,000,000
Lumara Health Inc Member
Reconciliation of contingent consideration obligations related to acquisition rights
Acquisition-related contingent consideration	206,600,000			206,600,000			205,000,000
Adjustments to fair value of contingent consideration				$1,600,000

Accounts_Receivable_Net_Detail

Accounts Receivable, Net (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Accounts Receivable, Net
Net Accounts receivable	38,172	6,842
Amerisource Bergen Drug Corporation [Member]
Customers representing greater than 10% of accounts receivable balances
Accounts receivable by major customer (as a percent)	45.00%	43.00%
McKesson Corporation [Member]
Customers representing greater than 10% of accounts receivable balances
Accounts receivable by major customer (as a percent)	12.00%	29.00%
Cardinal Health Inc [Member]
Customers representing greater than 10% of accounts receivable balances
Accounts receivable by major customer (as a percent)		19.00%
Cardinal Health Inc [Member] | Maximum
Customers representing greater than 10% of accounts receivable balances
Accounts receivable by major customer (as a percent)	10.00%

Inventories_Details

Inventories (Details) (USD $)	3 Months Ended								12 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Nov. 12, 2014
Inventories
Raw materials	$14,188,000				$3,157,000				$14,188,000	$3,157,000
Work in process	5,965,000				8,322,000				5,965,000	8,322,000
Finished goods	20,457,000				5,738,000				20,457,000	5,738,000
Total inventories	40,610,000				17,217,000				40,610,000	17,217,000
Raw materials	7,798,000								7,798,000
Total Inventories	48,408,000				17,217,000				48,408,000	17,217,000
Inventories disclosure
Inventories												30,300,000
Cost of product sales	11,758,000	2,968,000	2,743,000	2,837,000	3,326,000	2,547,000	3,145,000	2,942,000	20,306,000	11,960,000	14,220,000
Inventory expensed									1,309,000	2,175,000	1,822,000
Fair Value Adjustment to Inventory [Member]
Inventories disclosure
Inventories												26,100,000
Amount recognized in current period									1,300,000
Balance	24,800,000								24,800,000
2015									11,100,000
2016									3,500,000
2017									4,000,000
2018									3,500,000
2019									2,700,000
Research and Development Expense [Member]
Inventories disclosure
Inventory expensed									700,000	1,100,000
Cost of Sales [Member]
Inventories disclosure
Inventory expensed									$600,000	$1,100,000

Property_and_Equipment_Net_Det

Property and Equipment, Net (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Property and Equipment
Property and Equipment, gross	$2,497,000	$2,342,000
Less - accumulated depreciation	-978,000	-496,000
Property and equipment, net	1,519,000	1,846,000
Additions to leasehold improvements, furniture and fixtures	147,000	1,632,000	47,000
Depreciation expense	500,000	3,000,000	4,200,000
Furniture and Fixtures [Member]
Property and Equipment
Property and Equipment, gross	1,574,000	1,536,000
Leasehold Improvements [Member]
Property and Equipment
Property and Equipment, gross	430,000	430,000
Laboratory and Production Equipment [Member]
Property and Equipment
Property and Equipment, gross	493,000	376,000
Office Building [Member]
Property and Equipment
Accelerated depreciation expense		1,900,000	1,400,000
Impairment loss			$1,100,000

Goodwill_and_Intangible_Assets2

Goodwill and Intangible Assets, Net (Details) (USD $)	12 Months Ended			0 Months Ended
	Dec. 31, 2014	Dec. 31, 2012	Dec. 31, 2013	Jun. 06, 2013
Intangible Assets, Net
Goodwill	$205,824,000
Amortization of intangible assets	5,100,000	0
Finite-Lived Intangible Assets, Net [Abstract]
Cost	893,093,000		16,893,000
Accumulated Amortization	5,185,000		49,000
Net	887,908,000		16,844,000
Business Combination, Consideration Transferred [Abstract]
Goodwill	205,824,000
Expected future annual amortization expense
Year Ended December 31, 2015	51,886,000
Year Ended December 31, 2016	64,977,000
Year Ended December 31, 2017	76,679,000
Year Ended December 31, 2018	84,359,000
Year Ended December 31, 2019	55,746,000
Total	333,647,000
Maximum
Intangible Assets, Net
Amortization of intangible assets			100,000
Lumara Health Inc Member
Intangible Assets, Net
Goodwill	205,800,000
Useful life	20 years
Business Combination, Consideration Transferred [Abstract]
Goodwill	205,800,000
PlasmaTech Biopharmaceuticals Inc Member
Intangible Assets, Net
Acquired finite-lived intangible assets	16,900,000
Useful life	10 years
Business Combination, Consideration Transferred [Abstract]
Acquired finite-lived intangible assets	16,900,000
Licensing Agreements [Member] | Lumara Health Inc Member
Intangible Assets, Net (Excluding Goodwill) [Abstract]
Cost	79,100,000
Net	79,100,000
Licensing Agreements [Member]
Finite-Lived Intangible Assets, Net [Abstract]
Cost	813,993,000		16,893,000
Accumulated Amortization	5,185,000		49,000
Net	808,808,000		16,844,000
Licensing Agreements [Member] | Lumara Health Inc Member
Finite-Lived Intangible Assets, Net [Abstract]
Cost	797,100,000
Accumulated Amortization	4,834,000
Net	792,266,000
Licensing Agreements [Member] | PlasmaTech Biopharmaceuticals Inc Member
Intangible Assets, Net
Acquired finite-lived intangible assets				16,893,000
Finite-Lived Intangible Assets, Net [Abstract]
Cost	16,893,000		16,893,000
Accumulated Amortization	351,000		49,000
Net	16,542,000		16,844,000
Business Combination, Consideration Transferred [Abstract]
Purchase price paid				17,134,000
Acquired finite-lived intangible assets				$16,893,000

Current_and_Long_Term_Liabilit1

Current and Long- Term Liabilities (Details) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2010	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2008
Accrued Expenses
Commercial rebates, fees and returns			$44,807,000	$4,839,000
Professional, license, and other fees and expenses			14,888,000	1,932,000
Salaries, bonuses, and other compensation			10,176,000	5,419,000
Clinical, manufacturing and regulatory consulting fees and expenses			7,181,000	7,834,000
Restructuring expense			1,952,000
Commercial consulting fees and expenses			1,089,000	1,301,000
Short-term contingent consideration			718,000	941,000
Total accrued expenses			80,811,000	22,266,000
Deferred Revenues
Total short-term deferred revenues			44,376,000	8,226,000
Total long-term deferred revenues				44,534,000
License Development and Commercialization Agreement with Takeda [Member]
Deferred Revenues
Total short-term deferred revenues			44,376,000	8,226,000
Total long-term deferred revenues				43,534,000
Amortization period for recognizing nonsubstantive milestone payments		10 years
Milestone payments received under agreement related to commercial launches	18,000,000
Takeda Upfront Payments and Milestone Payments Recognized [Member]
Deferred Revenues
Deferred revenue recognized in earnings related to product sales			8,200,000	7,900,000
Accelerated recognition of deferred revenue			300,000	300,000
Deferred revenues			41,200,000
Takeda Product Shipment [Member]
Deferred Revenues
Deferred revenue recognized in earnings related to product sales			2,500,000
Deferred revenues			3,200,000
Other Deferred Revenue Arrangement [Member]
Deferred Revenues
Deferred revenue recognized in earnings related to product sales			1,000,000
Collaboration and Exclusive License Agreement with 3SBio Inc [Member]
Deferred Revenues
Total long-term deferred revenues				1,000,000
Upfront payment received					$1,000,000

Income_Taxes_Details

Income Taxes (Details) (USD $)	3 Months Ended	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Current Income Tax Expense (Benefit), Continuing Operations [Abstract]
Current Income Tax Expense (Benefit)	($153,159,000)	($153,159,000)		($854,000)
Deferred Income Tax Expense (Benefit), Continuing Operations [Abstract]
Federal		-142,884,000		-833,000
State		-10,275,000		-21,000
Total Deferred		-153,159,000		-854,000
Total income tax benefit		-153,159,000		-854,000
Reconciliation of statutory U.S. federal income tax rate to effective income tax rate
Statutory U.S. federal tax rate (as a percent)		-34.00%	-34.00%	-34.00%
State taxes, net of federal benefit (as a percent)		-7.90%	2.40%	4.20%
Equity-based compensation expense (as a percent)		10.60%	9.40%	42.40%
Permanent items, net (as a percent)		16.00%	5.30%	1.20%
Tax credits (as a percent)		-3.00%	0.50%	0.80%
Valuation allowance (as a percent)		-864.90%	16.40%	-19.50%
Total tax (benefit) expense (as a percent)		-883.20%	0.00%	-4.90%
Assets.
Net operating loss carryforwards	188,873,000	188,873,000	85,269,000
Tax credit carryforwards	24,574,000	24,574,000	12,396,000
Deferred revenue	17,216,000	17,216,000	20,368,000
Equity-based compensation expense	3,436,000	3,436,000	4,176,000
Capitalized research & development	32,359,000	32,359,000	39,214,000
Intangibles	272,000	272,000	680,000
Debt instruments	731,000	731,000
Reserves	7,782,000	7,782,000
Property, plant and equipment	61,000	61,000
Other	5,014,000	5,014,000	4,371,000
Liabilities.
Property, Plant, and Equipment Depreciation			-58,000
Intangible Assets and Inventory Amortization	-290,491,000	-290,491,000
Other	-1,795,000	-1,795,000
Gross deferred taxes	-11,968,000	-11,968,000	166,416,000
Valuation allowance	-33,557,000	-33,557,000	-166,416,000
Net deferred taxes	-45,525,000	-45,525,000
Increase (Decrease) in valuation allowance		$132,900,000

Income_Taxes_Details_2

Income Taxes (Details 2) (USD $)	3 Months Ended	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2014	Dec. 31, 2012	Dec. 31, 2013
Income Taxes
Increase (Decrease) in valuation allowance		$132,900,000
Income tax benefit	-153,159,000	-153,159,000	-854,000
Unrecognized tax benefits	0	0		0
Lumara Health
Income Taxes
Increase (Decrease) in valuation allowance		20,300,000
Federal
Income Taxes
NOL carryforwards	542,300,000	542,300,000
Capital loss carryforwards	2,100,000	2,100,000
Additional NOLs	30,600,000	30,600,000
Tax credits	21,600,000	21,600,000
Federal | Lumara Health
Income Taxes
NOL carryforwards	254,100,000	254,100,000
Tax credits	12,000,000	12,000,000
State
Income Taxes
Additional NOLs	5,400,000	5,400,000
Tax credits	4,500,000	4,500,000
State | Maximum
Income Taxes
NOL carryforwards	242,200,000	242,200,000
State | Lumara Health
Income Taxes
NOL carryforwards	$124,700,000	$124,700,000

Accumulated_Other_Comprehensiv2

Accumulated Other Comprehensive Loss (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Changes in accumulated other comprehensive income, net of tax
Beginning Balance	($3,491)	($3,247)
Other comprehensive income (loss) before reclassifications	-191	-268
Gain (loss) reclassified from other accumulated comprehensive loss	65	24
Ending Balance	($3,617)	($3,491)

EquityBased_Compensation_Detai

Equity-Based Compensation (Details) (USD $)	12 Months Ended			1 Months Ended				0 Months Ended	1 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Feb. 28, 2013	31-May-13	31-May-10	31-May-09	Nov. 12, 2014	Dec. 31, 2014	Aug. 31, 2014
	item
Equity-Based Compensation
Number of equity compensation plans	3
Equity compensation plans
Total equity-based compensation expense	$8,625,000	$8,004,000	$7,024,000
Employee and Non Employee Stock Option [Member]
Equity compensation plans
Number of stock options outstanding (in shares)	2,996,383	2,819,676							2,996,383
Granted (in shares)	1,391,776
Forfeited (in shares)	-720,493
Expense recognition period	2 years
Restricted Stock Units (RSUs) [Member]
Equity compensation plans
Number of restricted stock units outstanding (in shares)	541,226	465,394							541,226
Granted (in shares)	356,626
Vested (in shares)	-151,518
Forfeited (in shares)	-129,276
Expense recognition period	2 years
Restricted Stock Units (RSUs) [Member] | Senior Management [Member]
Equity compensation plans
Award vesting period				3 years
Granted (in shares)				82,500
Expense recognition period				3 years
Restricted Stock Units (RSUs) [Member] | Senior Management [Member] | Maximum
Equity compensation plans
Fair value of awards issued				700,000
Equity Incentive Plan 2007 [Member]
Equity compensation plans
Shares authorized for issuance					1,100,000	800,000	600,000
Number of options and restricted stock units granted since inception (in shares)	7,414,752								7,414,752
Number of stock options expired or terminated since inception (in shares)	3,112,356								3,112,356
Number of restricted stock units forfeited since inception (in shares)	703,124								703,124
Stock options exercised since inception (in shares)	610,297								610,297
Shares of common stock issued pursuant to vested restricted stock units since inception	577,132
Number of stock options outstanding (in shares)	2,051,017								2,051,017
Number of restricted stock units outstanding (in shares)	360,826								360,826
Remaining number of shares available for future grants	1,707,989								1,707,989
Equity Incentive Plan 2007 [Member] | Employee and Non Employee Stock Option [Member]
Equity compensation plans
Reduction in number of shares available for issuance							1
Equity Incentive Plan 2007 [Member] | Employee and Non Employee Stock Option [Member] | Minimum [Member]
Equity compensation plans
Expiration term	7 years
Equity Incentive Plan 2007 [Member] | Employee and Non Employee Stock Option [Member] | Maximum
Equity compensation plans
Expiration term	10 years
Equity Incentive Plan 2007 [Member] | Restricted Stock Units (RSUs) [Member]
Equity compensation plans
Reduction in number of shares available for issuance							1.5
Award vesting period	4 years
Stock 2000 Plan
Equity compensation plans
Number of options and restricted stock units granted since inception (in shares)	2,182,700								2,182,700
Number of stock options expired or terminated since inception (in shares)	1,049,339								1,049,339
Number of restricted stock units forfeited since inception (in shares)	1,500								1,500
Stock options exercised since inception (in shares)	1,054,095								1,054,095
Shares of common stock issued pursuant to vested restricted stock units since inception	42,500
Number of stock options outstanding (in shares)	35,266								35,266
Number of restricted stock units outstanding (in shares)	0								0
Remaining number of shares available for future grants	0								0
Stock 2000 Plan | Employee and Non Employee Stock Option [Member]
Equity compensation plans
Expiration term	10 years
Lumara 2013 Plan
Equity compensation plans
Shares authorized for issuance								200,000
Number of options and restricted stock units granted since inception (in shares)	64,000								64,000
Number of stock options outstanding (in shares)	44,000								44,000
Number of restricted stock units outstanding (in shares)	20,000								20,000
Remaining number of shares available for future grants	136,000								136,000
Lumara 2013 Plan | Minimum [Member]
Equity compensation plans
Expiration term	7 years
Lumara 2013 Plan | Maximum
Equity compensation plans
Expiration term	10 years
Other Equity Compensation Grants [Member] | Employee and Non Employee Stock Option [Member] | Senior Management [Member]
Equity compensation plans
Award vesting period	4 years	4 years
Granted (in shares)	165,000	270,000	300,000
Other Equity Compensation Grants [Member] | Employee and Non Employee Stock Option [Member] | Lumara Health Employees [Member]
Equity compensation plans
Granted (in shares)									304,600
Other Equity Compensation Grants [Member] | Restricted Stock Units (RSUs) [Member] | Senior Management [Member]
Equity compensation plans
Award vesting period	4 years	4 years
Granted (in shares)	87,900	115,000	100,000							195,000
Fair value of awards issued										6,300,000
Total equity-based compensation expense	$100,000
Expense recognition period										3 years
Other Equity Compensation Grants [Member] | Restricted Stock Units (RSUs) [Member] | Lumara Health Employees [Member]
Equity compensation plans
Granted (in shares)									22,600
Other Equity Compensation Grants [Member] | Share Based Compensation Award Vesting At Specific Date One Member | Restricted Stock Units (RSUs) [Member] | Senior Management [Member]
Equity compensation plans
Vesting rights percentage										50.00%
Other Equity Compensation Grants [Member] | Share Based Compensation Award Vesting At Specific Date Two Member | Restricted Stock Units (RSUs) [Member] | Senior Management [Member]
Equity compensation plans
Vesting rights percentage										100.00%
Other Equity Compensation Plan Outside The 2007 Plan [Member]
Equity compensation plans
Number of options and restricted stock units granted since inception (in shares)	1,344,000								1,344,000
Number of stock options expired or terminated since inception (in shares)	146,250								146,250
Number of restricted stock units forfeited since inception (in shares)	67,500								67,500
Stock options exercised since inception (in shares)	28,750								28,750
Shares of common stock issued pursuant to vested restricted stock units since inception	75,000

EquityBased_Compensation_Detai1

Equity-Based Compensation (Details 2) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Equity-based compensation expense
Total equity-based compensation expense	$8,625	$8,004	$7,024
Cost of Sales [Member]
Equity-based compensation expense
Total equity-based compensation expense	122	121	225
Research and Development Expense [Member]
Equity-based compensation expense
Total equity-based compensation expense	1,596	2,149	1,994
Selling, General and Administrative Expenses [Member]
Equity-based compensation expense
Total equity-based compensation expense	$6,907	$5,734	$4,805

EquityBased_Compensation_Detai2

Equity-Based Compensation (Details 3) (USD $)	12 Months Ended
In Millions, except Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Employees [Member]
Weighted average assumptions utilized for purposes of valuing grants of options to employees and non-employee directors
Risk free interest rate (as a percent)	1.56%	0.95%	0.66%
Expected volatility (as a percent)	47.00%	59.00%	57.00%
Expected option term	5 years	5 years	4 years 7 months 28 days
Non Employee Director [Member]
Weighted average assumptions utilized for purposes of valuing grants of options to employees and non-employee directors
Risk free interest rate (as a percent)	1.28%	0.85%	0.68%
Expected volatility (as a percent)	46.00%	46.00%	56.00%
Expected option term	4 years	4 years	4 years
Employee and Non Employee Stock Option [Member]
Options
Outstanding at beginning of year (in shares)	2,819,676
Granted (in shares)	1,391,776
Exercised (in shares)	-494,576
Expired and/or forfeited (in shares)	-720,493
Outstanding at end of year - vested and unvested expected to vest (in shares)	2,688,944
Exercisable at end of year (in shares)	946,787
Outstanding at end of year - vested and unvested expected to vest (in shares)	2,688,944
Weighted Average Exercise Price
Outstanding at beginning of year (in dollars per share)	21.31
Granted (in dollars per share)	25.75
Exercised (in dollars per share)	19.43
Expired and/or forfeited (in dollars per share)	25.81
Outstanding at end of year (in dollars per share)	22.6	21.31
Outstanding at end of year - vested and unvested expected to vest (in dollars per share)	22.6
Exercisable at end of year (in dollars per share)	22.47
Outstanding at end of year	7 years 8 months 12 days
Outstanding at end of year - vested and unvested expected to vest	7 years 7 months 6 days
Exercisable at end of year	6 years
Aggregate Intrinsic Value
Outstanding at end of year	60,546
Outstanding at end of year - vested and unvested expected to vest	54,410
Exercisable at end of year	60,459
Additional Disclosures
Weighted average grant date fair value (in dollars per share)	10.63	8.6	6.9
Options vested (in shares)	686,321
Total grant date fair value of options vested (in dollars)	5.7	4.5	5.5
Aggregate intrinsic value of options exercised (in dollars)	5.9	1	0.1

EquityBased_Compensation_Detai3

Equity-Based Compensation (Details 4) (USD $)	12 Months Ended
In Millions, except Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Additional disclosures
Equity-based compensation expense, net of forfeitures, attributable to future periods (in dollars)	$24
Restricted Stock Units (RSUs) [Member]
Unvested Restricted Stock Units
Outstanding at beginning of year (in shares)	465,394
Granted (in shares)	356,626
Vested (in shares)	-151,518
Forfeited (in shares)	-129,276
Outstanding at end of year (in shares)	541,226	465,394
Outstanding at end of year and expected to vest (in shares)	465,686
Weighted Average Grant Date Fair Value
Outstanding at beginning of year (in dollars per share)	$17.28
Granted (in dollars per share)	$22.88	$16.31	$15.64
Vested (in dollars per share)	$17.71
Forfeited (in dollars per share)	$18.25
Outstanding at end of year (in dollars per share)	$20.62	$17.28
Outstanding at end of year and expected to vest (in dollars per share)	$20.59
Additional disclosures
Total grant date fair value	2.7	2.8	3.5
Equity-based compensation expense, net of forfeitures, attributable to future periods (in dollars)	8.1
Weighted average amortization periods	2 years
Employee and Non Employee Stock Option [Member]
Additional disclosures
Equity-based compensation expense, net of forfeitures, attributable to future periods (in dollars)	$15.90
Weighted average amortization periods	2 years
Equity Incentive Plan 2007 [Member]
Unvested Restricted Stock Units
Outstanding at end of year (in shares)	360,826
Equity Incentive Plan 2007 [Member] | Restricted Stock Units (RSUs) [Member]
Equity compensation plans
Shares issued	356,626

Employee_Savings_Plan_Details

Employee Savings Plan (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Employee Savings Plan
Company contribution as a percentage of each employee's combined salary and certain other compensation for the plan year under the 401(k) Plan	3.00%
Amount of company contribution for the 401(k) Plan	$0.80	$0.70	$0.80

Stockholders_Equity_Details

Stockholders' Equity (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Feb. 28, 2014
Preferred Stock
Exercise price (in dollars per share)		$34.12
Rights [Member]
Preferred Stock
Exercise price (in dollars per share)	$80
Exercise price before adjustment (in dollars per share)	$250
Percentage of beneficial ownership to acquire to make the Rights exercisable	4.99%
Rights [Member] | Minimum [Member]
Preferred Stock
Percentage of ownership before the NOL Amendment	20.00%

Business_Segments_Details

Business Segments (Details)	12 Months Ended
	Dec. 31, 2014
	item
Business Segments
Number of business segments	1

Commitments_and_Contingencies_1

Commitments and Contingencies (Details) (USD $)	0 Months Ended	12 Months Ended
	Sep. 12, 2014	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Nov. 12, 2014	Jun. 30, 2013
Minimum Lease Payments
Security deposit in the form of an irrevocable letter of credit		400,000	$400,000
Business Acquisition [Line Items]
Convertible Notes and Term Loans		167,441,000
Purchase Commitments
Remaining purchase commitments under various agreements with third-parties			4,800,000
Other Funding Commitments
Accrued expenses for clinical studies		1,900,000
Credit Facility
Business Acquisition [Line Items]
Convertible Notes and Term Loans		540,000,000
Lumara Health Inc Member
Business Acquisition [Line Items]
Future contingent payments, maximum					350,000,000
Settled Litigation [Member]
Litigation settlement
Agreed settlement amount	3,750,000
Prepaid expense and other assets recorded relating to settlement amount		3,750,000
Accrual expenses		3,750,000
Minimum [Member]
Patent appeals and market exclusivity
Ferumoxytol term of data and market exclusivity even if there is no successful outcome from the appeals process		8 years
Maximum
Indemnification Obligations
Initial indemnification exposure for actions or events involving officers, directors and certain employees		1,000,000
Patent appeals and market exclusivity
Ferumoxytol term of data and market exclusivity even if there is no successful outcome from the appeals process		10 years
Real Estate [Member]
Minimum Lease Payments
Year Ended December 31, 2015		1,451,000
Year Ended December 31, 2016		1,456,000
Year Ended December 31, 2017		1,462,000
Year Ended December 31, 2018		1,174,000
Total		5,543,000
Waltham Premises [Member]
Facility Lease Obligations
Expenses associated with operating leases		800,000	1,500,000	1,700,000
Initial lease term		5 years 2 months
Number of successive five year extension terms		1
Extension period of the lease terms		5 years
Minimum Lease Payments
Security deposit in the form of an irrevocable letter of credit						400,000
Security deposit as of second anniversary of the commencement date						300,000
St Louis Premises [Member]
Facility Lease Obligations
Expenses associated with operating leases		100,000
Automobiles Laboratory and Office Equipment [Member]
Facility Lease Obligations
Expenses associated with operating leases		200,000	-300,000	900,000
Minimum Lease Payments
Year Ended December 31, 2015		600,000

Collaborative_Agreements_Detai

Collaborative Agreements (Details) (USD $)

3 Months Ended

12 Months Ended

1 Months Ended

12 Months Ended

Dec. 31, 2014

Sep. 30, 2014

Jun. 30, 2014

Mar. 31, 2014

Dec. 31, 2013

Sep. 30, 2013

Jun. 30, 2013

Mar. 31, 2013

Dec. 31, 2014

Dec. 31, 2013

Dec. 31, 2012

Jun. 30, 2012

Apr. 30, 2010

Mar. 31, 2010

Dec. 31, 2010

Dec. 31, 2008

Collaborative Agreements

Cost of product sales

$11,758,000

$2,968,000

$2,743,000

$2,837,000

$3,326,000

$2,547,000

$3,145,000

$2,942,000

$20,306,000

$11,960,000

$14,220,000

Deferred revenues, short-term

44,376,000

8,226,000

44,376,000

8,226,000

Deferred revenues, long-term

44,534,000

44,534,000

License Development and Commercialization Agreement with Takeda [Member]

Collaborative Agreements

Number of deliverables

4

4

Upfront payment received

60,000,000

Additional upfront payment

1,000,000

Period of recognition of deferred revenues

12 months

10 years

Milestone payments revenue recognized under the agreement

8,200,000

15,000,000

Milestone revenue

18,000,000

Other reimbursement revenues

1,700,000

500,000

400,000

Product sales and royalty revenue recognized

3,500,000

Cost of product sales

2,800,000

Accelerated Recognition Of Deferred Revenue

300,000

Deferred revenues, short-term

3,200,000

3,200,000

License Development and Commercialization Agreement with Takeda [Member] | Termination Agreement [Member]

Collaborative Agreements

Milestone revenue

3,000,000

Other reimbursement revenues

6,700,000

Transfer period

60 days

Extension period

30 days

Transition period

180 days

Transition extension period

180 days

Percentage paid

5.00%

Withdrawal period

120 days

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

Collaborative Agreements

Upfront payment received

$1,000,000

Debt_Details

Debt (Details) (USD $)	0 Months Ended	3 Months Ended				12 Months Ended	0 Months Ended
Share data in Millions, except Per Share data, unless otherwise specified	Feb. 13, 2014	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2014	Feb. 14, 2014	Feb. 28, 2014	Dec. 31, 2013	Feb. 11, 2014
Liability component:
Principal		$200,000,000				$200,000,000
Less: debt discount, net		-32,559,000				-32,559,000
Net carrying amount		167,441,000				167,441,000
Debt Instrument, Fair Value Disclosure		332,000,000				332,000,000
Equity component		38,188,000				38,188,000
Interest rate (as a percent)		2.50%				2.50%			2.50%
Effective interest rate on liability component (as a percent)		7.23%				7.23%
Total interest expense recognized
Total interest expense		7,041,000	3,129,000	3,051,000	1,476,000	14,697,000
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 hedges, net of tax					39,800,000	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%
Proceeds from issuance of warrants						25,620,000
Convertible Debt [Member]
Liability component:
Net carrying amount		167,400,000				167,400,000
Net proceeds from issuance of convertible debt							193,300,000
Aggregate principal amount of notes issued		200,000,000				200,000,000	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
Interest rate (as a percent)		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
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
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
Debt issuance costs allocated to the liability component							5,400,000
Expected life of the debt						5 years
Total interest expense recognized
Contractual interest expense						4,375,000
Amortization of debt issuance costs						800,000
Amortization of debt discount						5,629,000
Total interest expense						10,804,000
Convertible Debt [Member] | Debt Instrument Convertible Covenant One [Member]
Liability component:
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%
Convertible Debt [Member] | Debt Instrument Convertible Covenant Two [Member]
Liability component:
Principal amount used for debt instrument conversion ratio		1,000				1,000
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
Convertible Debt [Member] | Debt Instrument Convertible Covenant Two [Member] | Maximum
Liability component:
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%
Convertible Debt [Member] | Debt Instrument Convertible Covenant Three [Member]
Liability component:
Principal amount used for debt instrument conversion ratio		$1,000				$1,000

Debt_Details_2

Debt (Details 2) (USD $)	12 Months Ended	0 Months Ended	3 Months Ended
	Dec. 31, 2014	Nov. 12, 2014	Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2013
Debt
Proceeds from Issuance of Long-term Debt	$327,509,000
Interest rate (as a percent)	2.50%				2.50%
Debt Instrument, Interest Rate, Effective Percentage	7.23%
Long-term Debt, Total	293,905,000
Term Loan
Debt
2015	34,000,000
2016	51,000,000
2017	51,000,000
2018	51,000,000
2019	51,000,000
Thereafter	102,000,000
Long-term Debt, Total	340,000,000
Term Loan | Credit Facility
Debt
Principal amount of debt issued		340,000,000
Proceeds from Issuance of Long-term Debt		327,500,000
Debt Issuance Cost		12,500,000
Loans Payable	327,900,000
Interest rate (as a percent)	7.25%
Debt Instrument, Interest Rate, Effective Percentage	8.55%
Installment payment amount			12,800,000	8,500,000
Amount Of Voluntary Prepayment Or Mandatory Prepayment That Triggers Prepayment Premium	50,000,000
Prepayment Premium, Percentage Of Principal Amount Of Prepayment If Prepayment Made Before 12 Months From Closing Date	2.00%
Prepayment Premium, Percentage Of Principal Amount Of Prepayment If Prepayment Made After 12 Months But Before 24 Months From Closing Date	1.00%
Percentage of equity interests in domestic subsidiaries pledged as collateral for borrowing (as a percent)	100.00%
Percentage of equity interests in direct foreign subsidiaries pledged as collateral for borrowing (as a percent)	65.00%
Term Loan | Credit Facility | Excess Cash Flows, Range One
Debt
Annual Mandatory Prepayment Of Term Loans From Excess Cash Flows Range Percentage	75.00%
Total Net Leverage Ratio	2
Term Loan | Credit Facility | Excess Cash Flows, Range Two
Debt
Annual Mandatory Prepayment Of Term Loans From Excess Cash Flows Range Percentage	50.00%
Total Net Leverage Ratio	1
Term Loan | Credit Facility | Excess Cash Flows, Range Three
Debt
Annual Mandatory Prepayment Of Term Loans From Excess Cash Flows Range Percentage	25.00%
Total Net Leverage Ratio	0.5
Term Loan | Credit Facility | Excess Cash Flows, Range Four
Debt
Annual Mandatory Prepayment Of Term Loans From Excess Cash Flows Range Percentage	0.00%
Term Loan | Credit Facility | Forecast
Debt
Minimum Principal Amount Of Convertible Notes Outstanding That Triggers Maturity Acceleration	25,000,000
Minimum Principal Amount Of Term Loans Outstanding That Triggers Maturity Acceleration	50,000,000
Term Loan | Credit Facility | Eurodollar Rate
Debt
Basis Spread on Variable Rate		6.25%
Floor for variable rate		1.00%
Term Loan | Credit Facility | Prime Rate
Debt
Basis Spread on Variable Rate		5.25%
Floor for variable rate		2.00%
Term Loan | Maximum | Credit Facility
Debt
Cash netted from ratio calculation	25,000,000
Term Loan | Maximum | Credit Facility | March 30, 2015
Debt
Total Net Leverage Ratio	4.6
Term Loan | Maximum | Credit Facility | September 30, 2017
Debt
Total Net Leverage Ratio	1
Incremental Term Loans | Credit Facility
Debt
Principal amount of debt issued		$40,000,000

Restructuring_Details

Restructuring (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2012
Components of restructuring expenses and reserve
Employee severance, benefits and related costs	$2,023
Payments	-70
Accrued restructuring, end of period	1,953
Charges	2,023	2,215
Lumara Health Inc Member
Components of restructuring expenses and reserve
Charges	$2,000

Consolidated_Quarterly_Financi2

Consolidated Quarterly Financial Data-Unaudited (Details) (USD $)	3 Months Ended									12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Sep. 30, 2012	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Consolidated Quarterly Financial Data-Unaudited
U.S. product sales, net	$46,648	$22,547	$22,225	$17,375	$18,981	$19,347	$17,456	$15,578		$108,795	$71,362	$58,287
License fee and other collaboration revenues	3,462	2,182	2,122	3,120	2,329	1,998	2,055	2,003		10,886	8,385	26,475
Other product sales and royalties	3,143	765	455	340	401	271	138	299		4,703	1,109	616
Total revenues	53,253	25,494	24,802	20,835	21,711	21,616	19,649	17,880		124,384	80,856	85,378
Cost of product sales	11,758	2,968	2,743	2,837	3,326	2,547	3,145	2,942		20,306	11,960	14,220
Gross margin	41,495	22,526	22,059	17,998	18,385	19,069	16,504	14,938
Operating expenses	44,869	18,233	20,824	23,989	22,380	19,464	19,260	19,409
Interest expense	-7,041	-3,129	-3,051	-1,476						-14,697
Interest and dividend income, net	166	291	253	265	278	246	256	271		975	1,051	1,286
Gains on assets held for sale	1		2	100	59		566	299
Gains on investments, net	97	3	14		4	4	26	6		114	40	-1,466
Net income (loss) before income taxes	-10,151	1,458	-1,547	-7,102						-17,342	-9,602	-17,604
Income tax benefit	153,159									153,159		854
Net income (loss)	143,008	1,458	-1,547	-7,102	-3,654	-145	-1,908	-3,895		135,817	-9,602	-16,750
Net income (loss) per share - basic (in dollars per share)	$5.98	$0.07	($0.07)	($0.33)						$6.06	($0.44)	($0.78)
Net income (loss) per share - diluted (in dollars per share)	$4.67	$0.07	($0.07)	($0.33)						$5.45	($0.44)	($0.78)
Basic and diluted (in dollars per share)					($0.17)	($0.01)	($0.09)	($0.18)
Reduction in estimated Medicaid rebate reserve related to Feraheme sales						$23,200			$23,200		($568)	($621)

Valuation_and_Qualifying_Accou2

Valuation and Qualifying Accounts (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Allowance for Doubtful Accounts [Member]
Changes in valuation and qualifying accounts
Balance at Beginning of Period	$2,683	$1,771	$1,822
Additions	59,372	37,098	26,517
Deductions Charged to Reserves	-50,580	-36,186	-26,568
Balance at End of Period	11,475	2,683	1,771
Rebates Fees and Returns Reserves [Member]
Changes in valuation and qualifying accounts
Balance at Beginning of Period	4,799	3,448	5,943
Additions	52,079	11,820	6,729
Deductions Charged to Reserves	-13,126	-10,469	-9,224
Balance at End of Period	$43,752	$4,799	$3,448