Alkermes (ALKS) 10-KT 27 Feb 14 2013 FY Annual report (with FYE transition) Financial data

Document_and_Entity_Informatio

Document and Entity Information (USD $)	9 Months Ended
	Dec. 31, 2013	Feb. 13, 2014	Jun. 28, 2013
Document and Entity Information	'	'	'
Entity Registrant Name	'Alkermes plc.	'	'
Entity Central Index Key	'0001520262	'	'
Document Type	'10-KT	'	'
Document Period End Date	31-Dec-13	'	'
Amendment Flag	'false	'	'
Current Fiscal Year End Date	'--12-31	'	'
Entity Well-known Seasoned Issuer	'Yes	'	'
Entity Voluntary Filers	'No	'	'
Entity Current Reporting Status	'Yes	'	'
Entity Filer Category	'Large Accelerated Filer	'	'
Entity Public Float	'	'	$3,850,629,514
Entity Common Stock, Shares Outstanding	'	144,185,293	'
Document Fiscal Year Focus	'2013	'	'
Document Fiscal Period Focus	'FY	'	'

CONSOLIDATED_BALANCE_SHEETS

CONSOLIDATED BALANCE SHEETS (USD $)	Dec. 31, 2013	Mar. 31, 2013
In Thousands, unless otherwise specified
CURRENT ASSETS:	'	'
Cash and cash equivalents	$167,562	$96,961
Investments - short-term	194,669	124,391
Receivables, net	134,154	124,620
Inventory	46,218	43,483
Prepaid expenses and other current assets	27,535	19,133
Total current assets	570,138	408,588
PROPERTY, PLANT AND EQUIPMENT, NET	274,490	288,435
INTANGIBLE ASSETS - NET	537,565	575,993
GOODWILL	92,740	92,740
INVESTMENTS - LONG-TERM	87,764	82,827
OTHER ASSETS	14,891	21,708
TOTAL ASSETS	1,577,588	1,470,291
CURRENT LIABILITIES:	'	'
Accounts payable and accrued expenses	91,173	76,910
Long-term debt - short-term	6,750	6,750
Deferred revenue - short-term	2,974	2,270
Total current liabilities	100,897	85,930
LONG-TERM DEBT	357,543	362,258
DEFERRED TAX LIABILITIES, NET - LONG-TERM	29,169	37,603
OTHER LONG-TERM LIABILITIES	12,580	23,260
DEFERRED REVENUE - LONG-TERM	12,213	8,866
Total liabilities	512,402	517,917
COMMITMENTS AND CONTINGENCIES (Note 19)	'	'
SHAREHOLDERS' EQUITY:	'	'
Preferred stock, par value, $0.01 per share; 50,000,000 shares authorized; zero issued and outstanding at December 31, 2013 and March 31, 2013, respectively	'	'
Ordinary shares, par value, $0.01 per share; 450,000,000 shares authorized; 138,482,571 and 134,065,107 shares issued; 137,792,626 and 133,751,610 shares outstanding at December 31, 2013 and March 31, 2013, respectively	1,382	1,338
Treasury stock, at cost (689,945 and 313,497 shares at December 31, 2013 and March 31, 2013, respectively)	-17,833	-5,380
Additional paid-in capital	1,553,337	1,458,857
Accumulated other comprehensive income (loss)	10,574	-2,518
Accumulated deficit	-482,274	-499,923
Total shareholders' equity	1,065,186	952,374
TOTAL LIABILITIES AND SHAREHOLDERS' EQUITY	$1,577,588	$1,470,291

CONSOLIDATED_BALANCE_SHEETS_Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) (USD $)	Dec. 31, 2013	Mar. 31, 2013
CONSOLIDATED BALANCE SHEETS	'	'
Preferred stock, par value (in dollars per share)	$0.01	$0.01
Preferred stock, shares authorized	50,000,000	50,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value (in dollars per share)	$0.01	$0.01
Common stock, shares authorized	450,000,000	450,000,000
Common stock, shares issued	138,482,571	134,065,107
Common stock, shares outstanding	137,792,626	133,751,610
Treasury stock, shares	689,945	313,497

CONSOLIDATED_STATEMENTS_OF_OPE

CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE INCOME (LOSS) (USD $)	9 Months Ended	12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2013	Mar. 31, 2013	Mar. 31, 2012
REVENUES:	'	'	'
Manufacturing and royalty revenues	$371,039	$510,900	$326,444
Product sales, net	57,215	58,107	41,184
Research and development revenue	4,657	6,541	22,349
Total revenues	432,911	575,548	389,977
EXPENSES:	'	'	'
Cost of goods manufactured and sold	134,306	170,466	127,578
Research and development	128,125	140,013	141,893
Selling, general and administrative	116,558	125,758	137,632
Amortization of acquired intangible assets	38,428	41,852	25,355
Restructuring	'	12,300	'
Impairment of long-lived assets	'	3,346	45,800
Total expenses	417,417	493,735	478,258
OPERATING INCOME (LOSS)	15,494	81,813	-88,281
OTHER EXPENSE, NET:	'	'	'
Interest income	711	841	1,516
Interest expense	-10,379	-48,994	-28,111
Other (expense) income, net	-429	1,781	484
Total other expense, net	-10,097	-46,372	-26,111
INCOME (LOSS) BEFORE INCOME TAXES	5,397	35,441	-114,392
(BENEFIT) PROVISION FOR INCOME TAXES	-12,252	10,458	-714
NET INCOME (LOSS)	17,649	24,983	-113,678
EARNINGS (LOSS) PER COMMON SHARE:	'	'	'
Basic (in dollars per share)	$0.13	$0.19	($0.99)
Diluted (in dollars per share)	$0.12	$0.18	($0.99)
WEIGHTED AVERAGE NUMBER OF COMMON SHARES OUTSTANDING:	'	'	'
Basic (in shares)	135,960	131,713	114,702
Diluted (in shares)	144,961	137,100	114,702
COMPREHENSIVE INCOME (LOSS):	'	'	'
Net income (loss)	17,649	24,983	-113,678
Unrealized gains (losses) on marketable securities, net of tax:	'	'	'
Holding gains, net of tax of $8,217, none and $372, respectively	13,092	703	627
Less: Reclassification adjustment for gains included in net income (loss)	'	-1,030	'
Unrealized gains (losses) gains on marketable securities	13,092	-327	627
Unrealized (losses) gains on derivative contracts:	'	'	'
Unrealized losses on derivative contracts, net of tax of none, none and $(194), respectively	'	-72	-327
Less: Reclassification adjustment for losses included in net income (loss)	'	594	'
Unrealized gains (losses) on derivative contracts	'	522	-327
COMPREHENSIVE INCOME (LOSS)	$30,741	$25,178	($113,378)

CONSOLIDATED_STATEMENTS_OF_OPE1

CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE INCOME (LOSS) (Parenthetical) (USD $)	9 Months Ended	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Mar. 31, 2013	Mar. 31, 2012
CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE INCOME (LOSS)	'	'	'
Holding gains, tax	$8,217	$0	$372
Unrealized losses on derivative contracts, tax	$0	$0	($194)

CONSOLIDATED_STATEMENTS_OF_SHA

CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY (USD $)	Total	Non-voting Common Stock	Ordinary Shares	Additional Paid-In Capital	Accumulated Other Comprehensive Income (Loss)	Accumulated Deficit	Treasury Stock
In Thousands, except Share data, unless otherwise specified
BALANCE at Mar. 31, 2011	$392,018	$4	$1,055	$936,295	($3,013)	($411,228)	($131,095)
BALANCE (in shares) at Mar. 31, 2011	'	382,632	105,771,507	'	'	'	-10,069,208
Increase (Decrease) in Shareholders' Equity	'	'	'	'	'	'	'
Issuance of common stock to Elan Corporation, plc in connection with the purchase of Elan Drug Technologies	525,074	'	319	524,755	'	'	'
Issuance of common stock to Elan Corporation, plc in connection with the purchase of Elan Drug Technologies (in shares)	'	'	31,900,000	'	'	'	'
Issuance of common stock under employee stock plans	20,864	'	24	20,840	'	'	'
Issuance of common stock under employee stock plans (in shares)	'	'	2,398,422	'	'	'	'
Receipt of Alkermes' stock for the purchase of stock options or to satisfy minimum tax withholding obligations related to stock based awards	-3,676	'	'	'	'	'	-3,676
Receipt of Alkermes' stock for the purchase of stock options or to satisfy minimum tax withholding obligations related to stock based awards (in shares)	'	'	'	'	'	'	-205,901
Share-based compensation expense	28,615	'	'	28,615	'	'	'
Excess tax benefit from share-based compensation	4,335	'	'	4,335	'	'	'
Conversion of non-voting common stock to common stock	'	-4	4	'	'	'	'
Conversion of non-voting common stock to common stock (in shares)	'	-382,632	382,632	'	'	'	'
Cancellation of treasury stock	'	'	-102	-134,098	'	'	134,200
Cancellation of treasury stock (in shares)	'	'	-10,240,031	'	'	'	10,240,031
Unrealized gains on marketable securities, net of tax of $8,217 and $372 for nine months ended December 2013 and and twelve months ended March 2012 respectively	627	'	'	'	627	'	'
Unrealized loss on cash flow hedge, net of tax of $(194) for twelve months ended March 2012	-327	'	'	'	-327	'	'
Net income (loss)	-113,678	'	'	'	'	-113,678	'
BALANCE at Mar. 31, 2012	853,852	'	1,300	1,380,742	-2,713	-524,906	-571
BALANCE (in shares) at Mar. 31, 2012	'	'	130,212,530	'	'	'	-35,078
Increase (Decrease) in Shareholders' Equity	'	'	'	'	'	'	'
Issuance of common stock under employee stock plans	34,360	'	38	34,322	'	'	'
Issuance of common stock under employee stock plans (in shares)	'	'	3,852,577	'	'	'	'
Receipt of Alkermes' stock for the purchase of stock options or to satisfy minimum tax withholding obligations related to stock based awards	-4,809	'	'	'	'	'	-4,809
Receipt of Alkermes' stock for the purchase of stock options or to satisfy minimum tax withholding obligations related to stock based awards (in shares)	'	'	'	'	'	'	-278,419
Share-based compensation expense	34,926	'	'	34,926	'	'	'
Excess tax benefit from share-based compensation	8,867	'	'	8,867	'	'	'
Unrealized gains on marketable securities, net of tax of $8,217 and $372 for nine months ended December 2013 and and twelve months ended March 2012 respectively	703	'	'	'	703	'	'
Unrealized loss on cash flow hedge, net of tax of $(194) for twelve months ended March 2012	-72	'	'	'	-72	'	'
Reclassification of unrealized gains to realized gains	-1,030	'	'	'	-1,030	'	'
Reclassification of unrealized losses to realized losses	594	'	'	'	594	'	'
Net income (loss)	24,983	'	'	'	'	24,983	'
BALANCE at Mar. 31, 2013	952,374	'	1,338	1,458,857	-2,518	-499,923	-5,380
BALANCE (in shares) at Mar. 31, 2013	'	'	134,065,107	'	'	'	-313,497
Increase (Decrease) in Shareholders' Equity	'	'	'	'	'	'	'
Issuance of common stock under employee stock plans	49,077	'	44	49,033	'	'	'
Issuance of common stock under employee stock plans (in shares)	'	'	4,417,464	'	'	'	'
Receipt of Alkermes' stock for the purchase of stock options or to satisfy minimum tax withholding obligations related to stock based awards	-11,665	'	'	788	'	'	-12,453
Receipt of Alkermes' stock for the purchase of stock options or to satisfy minimum tax withholding obligations related to stock based awards (in shares)	'	'	'	'	'	'	-376,488
Share-based compensation expense	33,265	'	'	33,265	'	'	'
Excess tax benefit from share-based compensation	11,394	'	'	11,394	'	'	'
Unrealized gains on marketable securities, net of tax of $8,217 and $372 for nine months ended December 2013 and and twelve months ended March 2012 respectively	13,092	'	'	'	13,092	'	'
Net income (loss)	17,649	'	'	'	'	17,649	'
BALANCE at Dec. 31, 2013	$1,065,186	'	$1,382	$1,553,337	$10,574	($482,274)	($17,833)
BALANCE (in shares) at Dec. 31, 2013	'	'	138,482,571	'	'	'	-689,985

CONSOLIDATED_STATEMENTS_OF_SHA1

CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY (Parenthetical) (USD $)	9 Months Ended	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Mar. 31, 2012
CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY	'	'
Unrealized gains on marketable securities, tax	$8,217	$372
Unrealized loss on cash flow hedge, tax	$0	($194)

CONSOLIDATED_STATEMENTS_OF_CAS

CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $)	9 Months Ended	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Mar. 31, 2013	Mar. 31, 2012
CASH FLOWS FROM OPERATING ACTIVITIES:	'	'	'
Net income (loss)	$17,649	$24,983	($113,678)
Adjustments to reconcile net income (loss) to cash flows from operating activities:	'	'	'
Depreciation and amortization	70,765	73,751	47,884
Share-based compensation expense	33,409	34,716	28,826
Loss on debt refinancing transactions	'	19,670	'
Prepayment penalties in connection with debt refinancing transactions	'	-6,533	'
Excess tax benefit from share-based compensation	-11,394	-8,867	-4,335
Impairment of long-lived assets	'	3,346	45,800
Deferred income taxes	-15,393	-2,113	-14,556
Principal payments on long-term debt attributable to original issue discount	'	-2,657	'
Other non-cash charges	-5,731	5,698	4,342
Changes in assets and liabilities, excluding the effect of acquisitions:	'	'	'
Receivables	-9,534	-28,239	-14,014
Inventory, prepaid expenses and other assets	-6,345	-6,577	-4,879
Accounts payable and accrued expenses	16,126	19,406	15,552
Deferred revenue	4,051	-3,351	6,068
Other long-term liabilities	-1,382	3,318	508
Cash flows provided by (used in) operating activities	92,221	126,551	-2,482
CASH FLOWS FROM INVESTING ACTIVITIES:	'	'	'
Additions to property, plant and equipment	-19,054	-22,217	-16,988
Proceeds from the sale of equipment	52	193	35
Acquisition of Elan Drug Technologies, net of cash acquired	'	'	-494,774
Investment in Acceleron Pharmaceuticals, Inc.	'	'	-231
Investment in Civitas Therapeutics, Inc.	-1,191	'	'
Promissory note issued to Civitas Therapeutics, Inc.	'	-1,116	'
Purchases of investments	-135,643	-303,945	-228,229
Sales and maturities of investments	90,470	258,937	323,028
Cash flows used in investing activities	-65,366	-68,148	-417,159
CASH FLOWS FROM FINANCING ACTIVITIES:	'	'	'
Proceeds from the issuance of ordinary shares for share-based compensation arrangements	49,077	34,360	20,864
Excess tax benefit from share-based compensation	11,394	8,867	4,335
Proceeds from the issuance of long-term debt	'	366,483	444,100
Employee taxes paid related to net share settlement of equity awards	-11,665	-4,809	-3,676
Principal payments of long-term debt	-5,060	-449,944	-775
Cash flows provided by (used in) financing activities	43,746	-45,043	464,848
NET INCREASE IN CASH AND CASH EQUIVALENTS	70,601	13,360	45,207
CASH AND CASH EQUIVALENTS - Beginning of period	96,961	83,601	38,394
CASH AND CASH EQUIVALENTS - End of period	167,562	96,961	83,601
SUPPLEMENTAL CASH FLOW DISCLOSURE:	'	'	'
Cash paid for interest	9,596	7,656	21,658
Cash paid for taxes	704	5,921	10,068
Non-cash investing and financing activities:	'	'	'
Purchased capital expenditures included in accounts payable and accrued expenses	1,969	2,450	3,416
Investment in Civitas Therapeutics, Inc.	1,160	'	1,547
Issuance of common stock used in the acquisition of Elan Drug Technologies	'	'	$525,074

DESCRIPTION_OF_BUSINESS_AND_BA

DESCRIPTION OF BUSINESS AND BASIS OF PRESENTATION	9 Months Ended
	Dec. 31, 2013
DESCRIPTION OF BUSINESS AND BASIS OF PRESENTATION	'
DESCRIPTION OF BUSINESS AND BASIS OF PRESENTATION	'
	1. DESCRIPTION OF BUSINESS AND BASIS OF PRESENTATION
	Alkermes plc (the "Company") is a fully integrated, global biopharmaceutical company that applies its scientific expertise and proprietary technologies to develop innovative medicines that improve patient outcomes. The Company has a diversified portfolio of more than 20 commercial drug products and a substantial clinical pipeline of product candidates that address central nervous system ("CNS") disorders such as addiction, schizophrenia and depression. Headquartered in Dublin, Ireland, the Company has a research and development ("R&D") center in Waltham, Massachusetts; R&D and manufacturing facilities in Athlone, Ireland; and manufacturing facilities in Gainesville, Georgia and Wilmington, Ohio.
	On September 16, 2011, the business of Alkermes, Inc. and the drug technologies business ("EDT") of Elan Corporation, plc ("Elan") were combined under the Company (this combination is referred to as the "Business Combination", the "acquisition of EDT" or the "EDT acquisition") in a transaction accounted for as a reverse acquisition with Alkermes, Inc. treated as the accounting acquirer. As a result, the historical financial statements of Alkermes, Inc. are included in the comparative prior periods. Use of the terms such as "us," "we," "our," "Alkermes" or the "Company" is meant to refer to Alkermes plc and its consolidated subsidiaries, except where context makes it clear that the time period being referenced is prior to September 16, 2011, in which case such terms shall refer to Alkermes, Inc. and its consolidated subsidiaries. Prior to September 16, 2011, Alkermes, Inc. was an independent pharmaceutical company incorporated in the Commonwealth of Pennsylvania and traded on the NASDAQ Global Select Stock Market under the symbol "ALKS."
	Change in Fiscal Year
	On May 21, 2013, the Company's Audit and Risk Committee, with such authority delegated to it by the Company's Board of Directors, approved a change to its fiscal year-end from March 31 to December 31. This transition report on Form 10-K (the "Transition Report") covers the nine-month transition period ended December 31, 2013 and reflects the Company's financial results for the nine month period from April 1, 2013 through December 31, 2013 (the "Transition Period"). Prior to this Transition Report on Form 10-K, the Company's two most recent Annual Reports on Form 10-K cover the fiscal years ended March 31, 2013 and March 31, 2012, respectively, and reflect the results of the respective twelve-month periods from April 1 to March 31. Unless otherwise noted, all references to "fiscal years" in this Transition Report refer to the twelve month fiscal years that, prior to the Transition Period ended December 31, 2013 ended on March 31.

SUMMARY_OF_SIGNIFICANT_ACCOUNT

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES

9 Months Ended

Dec. 31, 2013

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES

'

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES

'

2. SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES

Principles of Consolidation

The consolidated financial statements include the accounts of Alkermes plc and its wholly-owned subsidiaries: Alkermes Ireland Holdings Limited; Alkermes Science Three Limited; Alkermes Pharma Ireland Limited; Alkermes Finance Ireland Limited; Alkermes Science One Limited; Alkermes Finance S.à r.l.; Alkermes Finance Ireland (No. 2) Limited; Alkermes U.S. Holdings, Inc.; Alkermes, Inc.; Eagle Holdings USA, Inc.; Alkermes Controlled Therapeutics, Inc.; Alkermes Europe, Ltd.; and Alkermes Gainesville LLC. Intercompany accounts and transactions have been eliminated.

Use of Estimates

The preparation of the Company's consolidated financial statements in accordance with accounting principles generally accepted in the United States ("U.S.") ("GAAP") requires management to make estimates, judgments and assumptions that may affect the reported amounts of assets, liabilities, revenues and expenses, and related disclosure of contingent assets and liabilities. On an on-going basis, the Company evaluates its estimates and judgments and methodologies, including those related to revenue recognition and related allowances, its collaborative relationships, clinical trial expenses, the valuation of inventory, impairment and amortization of intangibles and long-lived assets, share-based compensation, income taxes including the valuation allowance for deferred tax assets, valuation of investments and derivative instruments, litigation and restructuring charges. The Company bases its estimates on historical experience and on various other assumptions that are believed to be reasonable, the results of which form the basis for making judgments about the carrying values of assets and liabilities. Actual results may differ from these estimates under different assumptions or conditions.

Cash and Cash Equivalents

The Company values its cash and cash equivalents at cost plus accrued interest, which the Company believes approximates their market value. The Company considers only those investments which are highly liquid, readily convertible into cash and so near their maturity, generally three months from the date of purchase, that they present insignificant risk of change in value because of interest rate changes to be cash equivalents.

Investments

The Company has investments in various types of securities, including U.S. government and agency obligations, debt securities issued by foreign agencies and backed by foreign governments, corporate debt securities, and common stock and warrants of a public company with which the Company has a collaborative arrangement. The Company generally holds its interest-bearing investments with major financial institutions and in accordance with documented investment policies. The Company limits the amount of credit exposure to any one financial institution or corporate issuer. At December 31, 2013, substantially all these investments are classified as available-for-sale and are recorded at fair value.

Holding gains and losses on available-for-sale investments are considered "unrealized" and are reported within "Accumulated other comprehensive income (loss)," a component of shareholders' equity. The Company uses the specific identification method for reclassifying unrealized gains and losses into earnings when investments are sold. The Company conducts periodic reviews to identify and evaluate each investment that has an unrealized loss, in accordance with the meaning of other-than-temporary impairment and its application to certain investments, as required by GAAP. An unrealized loss exists when the current fair value of an individual security is less than its amortized cost basis. Unrealized losses on available-for-sale securities that are determined to be temporary, and not related to credit loss, are recorded in accumulated other comprehensive income (loss).

For available-for-sale debt securities with unrealized losses, the Company performs an analysis to assess whether it intends to sell or whether it would more likely than not be required to sell the security before the expected recovery of the amortized cost basis. If the Company intends to sell a security, or may be required to do so, the security's decline in fair value is deemed to be other-than-temporary and the full amount of the unrealized loss is recorded within earnings as an impairment loss. Regardless of the Company's intent to sell a security, the Company performs additional analysis on all securities with unrealized losses to evaluate losses associated with the creditworthiness of the security. Credit losses are identified where the Company does not expect to receive cash flows sufficient to recover the amortized cost basis of a security.

Certain of the Company's money market funds and held-to-maturity investments are restricted investments held as collateral under letters of credit related to certain of the Company's service provider agreements and lease agreements, respectively, and are included in "Investments—short-term" and "Investments—long-term", respectively, in the consolidated balance sheets.

Fair Value of Financial Instruments

The Company's financial assets and liabilities are recorded at fair value and are classified as Level 1, 2 or 3 within the fair value hierarchy, as described in the accounting standards for fair value measurement. The Company's financial assets and liabilities consist of cash equivalents and investments and are classified within the fair value hierarchy as follows:

Level 1–these valuations are based on a market approach using quoted prices in active markets for identical assets. Valuations of these products do not require a significant degree of judgment. Assets utilizing Level 1 inputs include investments in money market funds, U.S. treasury securities and the common stock of a publicly-traded company;

Level 2–these valuations are based on a market approach using quoted prices obtained from brokers or dealers for similar securities or for securities for which the Company has limited visibility into their trading volumes. Valuations of these financial instruments do not require a significant degree of judgment. Assets and liabilities utilizing Level 2 inputs include U.S. government agency debt securities, debt securities issued by foreign agencies and backed by foreign governments, investments in corporate debt securities that are trading in the credit markets and an interest rate swap contract; and

Level 3–these valuations are based on an income approach using certain inputs that are unobservable and are significant to the overall fair value measurement. Valuations of these products require a significant degree of judgment. During the nine months ended December 31, 2013, the Company's Level 3 investments consisted of warrants to purchase the common stock of a publicly-traded company.

The carrying amounts reflected in the consolidated balance sheets for cash and cash equivalents, accounts receivable, other current assets, accounts payable and accrued expenses approximate fair value due to their short-term nature.

Inventory

Inventory is stated at the lower of cost or market value. Cost is determined using the first-in, first-out method. Included in inventory are raw materials used in production of pre-clinical and clinical products, which have alternative future use and are charged to R&D expense when consumed.

Property, Plant and Equipment

Property, plant and equipment are recorded at cost, subject to review for impairment whenever events or changes in circumstances indicate that the carrying amount of the assets may not be recoverable. Expenditures for repairs and maintenance are charged to expense as incurred and major renewals and improvements are capitalized. Depreciation is calculated using the straight-line method over the following estimated useful lives of the assets:

Asset group

Term

Buildings and improvements

15 - 40 years

Furniture, fixtures and equipment

3 - 10 years

Leasehold improvements

Shorter of useful life or lease term

Goodwill and Intangible Assets

Goodwill represents the excess cost of the Company's investment in the net assets of acquired companies over the fair value of the underlying identifiable net assets at the date of acquisition. The Company's goodwill, which solely relates to the EDT acquisition in the twelve months ended March 31, 2012, has been assigned to a reporting unit which consists of the former EDT business. A reporting unit is an operating segment or sub-segment to which goodwill is assigned when initially recorded.

Goodwill is not amortized but is reviewed for impairment on an annual basis utilizing a two-step process. The first step requires the Company to compare the fair value of the reporting unit to its respective carrying value, which includes goodwill. If the fair value of the reporting unit exceeds its carrying value, the goodwill is not considered impaired. If the carrying value is higher than the fair value, there is an indication that an impairment may exist and the second step is required. In step two, the implied fair value of goodwill is calculated as the excess of the fair value of a reporting unit over the fair values assigned to its assets and liabilities. If the implied fair value of goodwill is less than the carrying value of the reporting unit's goodwill, the difference is recognized as an impairment loss.

The Company's finite-lived intangible assets consist of core developed technology and collaboration agreements, were recorded at fair value at the time of their acquisition and are stated within the Company's consolidated balance sheets net of accumulated amortization and impairments. The finite-lived intangible assets are amortized over their estimated useful lives using the economic use method, which reflects the pattern that the economic benefits of the intangible assets are consumed as revenue is generated from the underlying patent or contract. The useful lives of the Company's intangible assets are primarily based on the legal or contractual life of the underlying patent or contract, which does not include additional years for the potential extension or renewal of the contract or patent. The Company's intangible assets were all acquired as part of the EDT acquisition in the twelve months ended March 31, 2012, as described in Note 3, Acquisitions.

Impairment of Long-Lived Assets

The Company reviews long-lived assets to be held and used for impairment whenever events or changes in circumstances indicate that the carrying amount of the assets may not be recoverable. Conditions that would necessitate an impairment assessment include a significant decline in the observable market value of an asset, a significant change in the extent or manner in which an asset is used, or a significant adverse change that would indicate that the carrying amount of an asset or group of assets is not recoverable. Determination of recoverability is based on an estimate of undiscounted future cash flows resulting from the use of the asset and its eventual disposition. In the event that 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. Long-lived assets to be disposed of are carried at fair value less costs to sell them.

Asset Retirement Obligations

The Company recognized an asset retirement obligation for an obligation to remove leasehold improvements and other related activities at the conclusion of the Company's lease for its manufacturing facility located in Chelsea, Massachusetts, which it presently subleases. The carrying amount of the asset retirement obligation at December 31, 2013 and March 31, 2013 was $2.2 million and $2.0 million, respectively, and is included within "Other Long-Term Liabilities" in the accompanying consolidated balance sheets.

The following table shows changes in the carrying amount of the Company's asset retirement obligation at December 31, 2013 and March 31, 2013:

(In thousands)

Carrying

Amount

Balance, April 1, 2012

$

1,862

Accretion expense

187

Balance, March 31, 2013

$

2,049

Accretion expense

151

Balance, December 31, 2013

$

2,200

Revenue Recognition

Collaborative Arrangements

The Company has entered into a number of collaboration agreements with pharmaceutical companies including Ortho-McNeil-Janssen Pharmaceuticals, Inc. and Janssen Pharmaceutica International, a division of Cilag International AG ("Janssen") for RISPERDAL® CONSTA® and INVEGA® SUSTENNA®/XEPLION®, Acorda Therapeutics, Inc. ("Acorda") for AMPYRA®/FAMPYRA® and AstraZeneca for BYDUREON® (upon assuming sole responsibility for the development and commercialization of BYDUREON from Bristol-Myers Squibb Company ("Bristol-Myers")). Substantially all of the products developed under the Company's collaborative arrangements are currently being marketed as approved products. The Company receives payments for manufacturing services and/or royalties on product sales.

Manufacturing revenues—The Company recognizes manufacturing revenues from the sale of products it manufactures for resale by its collaborative partners. Manufacturing revenues are recognized when persuasive evidence of an arrangement exists, delivery has occurred and title to the product and associated risk of loss has passed to the customer, the sales price is fixed or determinable and collectability is reasonably assured. The sales price for certain of the Company's manufacturing revenues is based on the end-market sales price earned by its collaborative partners. As the end-market sale occurs after the Company has shipped its product and the risk of loss has passed to its collaborative partner, the Company estimates the sales price for its product based on information supplied to it by the Company's collaborative partners, its historical transaction experience and other third-party data. Differences between the actual manufacturing revenues and estimated manufacturing revenues are reconciled and adjusted for in the period in which they become known, which is generally the following quarter.

Royalty revenues—The Company recognizes royalty revenues related to the sale of products by its collaborative partners that incorporates the Company's technologies. Royalties, with the exception of those from AMPYRA, are earned under the terms of a license agreement in the period the products are sold by the Company's collaborative partner and collectability is reasonably assured. Royalties on AMPYRA are earned in the period the product is shipped to Acorda. Certain of the Company's royalty revenues are recognized by the Company based on information supplied to the Company by its collaborative partners and require estimates to be made. Differences between the actual royalty revenues and estimated royalty revenues are reconciled and adjusted for in the period in which they become known, which is generally the following quarter.

Research and development revenue—R&D revenue consists of funding that compensates the Company for formulation, pre-clinical and clinical testing under R&D arrangements with its collaborative partners. The Company generally bills its collaborative partners under R&D arrangements using a full-time equivalent ("FTE") or hourly rate, plus direct external costs, if any.

Certain of the Company's collaboration agreements entitle it to additional payments upon the achievement of performance-based milestones. If the achievement of a milestone is considered probable at the inception of the collaboration, the related milestone payment is included with other collaboration consideration, such as upfront payments and research funding, in the Company's revenue model. Milestones that involve substantial effort on the Company's part and the achievement of which are not considered probable at the inception of the collaboration are considered "substantive milestones," and are recognized in their entirety in the period in which the milestone is achieved. Consideration received from the achievement of milestones that are not considered to be "substantive milestones" are recognized under the proportional performance method whereby revenue is limited to the lesser of the cumulative amount of payments received or the cumulative amount of revenue earned.

Product Sales, Net

The Company's product sales consist of sales of VIVITROL in the U.S. to wholesalers, specialty distributors and specialty pharmacies. Product sales are recognized from the sale of VIVITROL when persuasive evidence of an arrangement exists, title to the product and associated risk of loss has passed to the customer, which is considered to occur when the product has been received by the customer, the sales price is fixed or determinable and collectability is reasonably assured.

The Company records its product sales net of the following significant categories of sales discounts and allowances as a reduction of product sales at the time VIVITROL is shipped:

•

Medicaid Rebates—the Company records accruals for rebates to states under the Medicaid Drug Rebate Program as a reduction of sales when the product is shipped into the distribution channel. The Company rebates individual states for all eligible units purchased under the Medicaid program based on a rebate per unit calculation, which is based on its Average Manufacturer Price ("AMP"). The Company estimates expected unit sales and rebates per unit under the Medicaid program and adjusts its rebate estimates based on actual unit sales and rebates per unit;

•

Chargebacks—wholesaler and specialty pharmacy chargebacks are discounts that occur when contracted customers purchase directly from an intermediary wholesale purchaser. Contracted customers, which consist primarily of federal government agencies purchasing under the federal supply schedule, generally purchase the product at its contracted price, plus a mark-up from the wholesaler. The wholesaler, in-turn, charges back to the Company the difference between the price initially paid by the wholesaler and the contracted price paid to the wholesaler by the customer. The allowance for chargebacks is based on actual and expected utilization of these programs. Chargebacks could exceed historical experience and the Company's estimates of future participation in these programs. To date, actual chargebacks have not differed materially from the Company's estimates;

•

Product Discounts—cash consideration, including sales incentives, given by us under distribution service agreements with a number of wholesaler, distributor and specialty pharmacy customers that provide them with the opportunity to earn discounts in exchange for the performance of certain services. To date, actual product discounts have not differed materially from the Company's estimates;

•

Co-pay Assistance—the Company has a program whereby a patient can receive up to $500 per month toward their co-payment, co-insurance or deductible, provided the patient meets certain eligibility criteria. Reserves are recorded upon the sale of VIVITROL. To date, actual co-pay assistance has not differed materially from the Company's estimates; and

•

Product Returns—in August 2012, the Company changed the way in which revenue is recognized on VIVITROL product sales. Prior to August 1, 2012, the Company did not have sufficient history to reasonably estimate returns related to VIVITROL shipments and, therefore, the Company deferred the recognition of revenue on shipments of VIVITROL until the product left the distribution channel. In August 2012, it was determined there was sufficient history to reliably estimate returns, and revenue on the sales of VIVITROL is now recognized upon delivery to wholesalers, distributors and pharmacies, which is the point in time the customer assumes the risks and rewards of ownership. This change in the method of revenue recognition resulted in a one-time $1.7 million increase to "Product sales, net" in the accompanying consolidated statements of operations and comprehensive income (loss), which was recognized during the three months ended September 30, 2012.

Based on this revised revenue recognition policy, a reserve is now estimated for future product returns on VIVITROL gross product sales. This estimate is based on historical return rates as well as specifically identified anticipated returns due to known business conditions and product expiry dates. Return amounts are recorded as a deduction to arrive at VIVITROL product sales, net. Once VIVITROL is returned, it is destroyed. At December 31, 2013, the product return reserve was estimated to be approximately 2% of product sales and amounts to $3.8 million.

Risk-Management Instruments

The Company's derivative activities are initiated within the guidelines of documented corporate risk management policies and do not create additional risk because gains and losses on derivative contracts offset losses and gains on the liabilities being hedged. At December 31, 2013, the Company's risk management instruments consisted of an interest rate swap agreement. The objective of the interest rate swap agreement is to limit the impact of fluctuations in interest rates in earnings related to the Company's long-term debt. The interest rate swap agreement is not designated as a hedging instrument and is recorded at fair value. The associated gains and losses related to the interest rate swap are recognized in "Interest expense" during the period of change. Refer to Note 12, Derivative Instruments, for additional information related to the Company's risk management instruments.

Foreign Currency

The Company's functional and reporting currency is the U.S. dollar. Transactions in foreign currencies are recorded at the exchange rate prevailing on the date of the transaction. The resulting monetary assets and liabilities are translated into U.S. dollars at exchange rates prevailing on the subsequent balance sheet date. Gains and losses as a result of translation adjustments are recorded within "Other (expense) income, net" in the accompanying consolidated statement of operations and comprehensive income (loss). During the nine months ended December 31, 2013 and the twelve months ended March 31, 2013 and 2012, the Company recorded a gain on foreign currency translation of $0.2 million, $0.1 million and $0.5 million, respectively.

Concentrations

Financial instruments that potentially subject the Company to concentrations of credit risk are accounts receivable and marketable securities. Billings to large pharmaceutical and biotechnology companies account for the majority of the Company's accounts receivable, and collateral is generally not required from these customers. To mitigate credit risk, the Company monitors the financial performance and credit worthiness of its customers. The following represents revenue and receivables from the Company's customers exceeding 10% of the total in each category as of December 31, 2013 and March 31, 2013 and 2012, for the nine months ended December 31, 2013 and the twelve months ended March 31, 2013 and 2012:

Twelve Months Ended

Nine Months Ended

March 31,

December 31, 2013

2013

2012

Customer

Receivables

Revenue

Receivables

Revenue

Receivables

Revenue

Janssen

46

%

44

%

32

%

35

%

30

%

48

%

Acorda

12

%

12

%

15

%

11

%

11

%

—

The Company generally holds its interest-bearing investments with major financial institutions, and in accordance with documented investment policies, the Company limits the amount of credit exposure to any one financial institution or corporate issuer. The Company's investment objectives are, first, to assure liquidity and conservation of capital and, second, to obtain investment income.

Geographic Information

Company revenues by geographic location, as determined by the location of the customer, and the location of its assets, are as follows:

Twelve Months Ended

Nine Months Ended

March 31,

(In thousands)

December 31, 2013

2013

2012

Revenue by region:

U.S.

$

269,005

$

380,565

$

212,859

Ireland

5,722

14,455

12,695

Rest of world

158,184

180,528

164,423

Assets by region:

Current assets:

U.S.

$

382,571

$

248,441

$

209,683

Ireland

187,023

159,544

122,077

Rest of world

544

603

7,393

Long-term assets:

U.S.:

Intangible assets

$

—

$

—

$

—

Goodwill

3,677

3,677

3,677

Other

225,559

229,691

213,729

Ireland:

Intangible assets

$

537,565

$

575,993

$

617,845

Goodwill

89,063

89,063

89,063

Other

151,586

163,279

171,750

Research and Development Expenses

For each of its R&D programs, the Company incurs both external and internal expenses. External R&D expenses include costs related to clinical and non-clinical activities performed by contract research organizations, consulting fees, laboratory services, purchases of drug product materials and third-party manufacturing development costs. Internal R&D expenses include employee-related expenses, occupancy costs, depreciation and general overhead. The Company tracks external R&D expenses for each of its development programs, however, internal R&D expenses are not tracked by individual program as they benefit multiple programs or its technologies in general.

Share-Based Compensation

The Company's share-based compensation programs grant awards which include stock options and restricted stock units ("RSUs"), which vest with the passage of time and, to a limited extent, vest based on the achievement of certain performance or market criteria. The Company issues new shares upon stock option exercise or the vesting of RSUs. Certain of the Company's employees are retirement eligible under the terms of the Company's stock option plans (the "Plans"), and stock option awards to these employees generally vest in full upon retirement. Since there are no effective future service requirements for these employees, the fair value of these awards is expensed in full on the grant date or upon meeting the retirement eligibility criteria, whichever is later.

Stock Options

Stock option grants to employees generally expire ten years from the grant date and generally vest one-fourth per year over four years from the anniversary of the date of grant, provided the employee remains continuously employed with the Company, except as otherwise provided in the plan. Stock option grants to directors are for ten-year terms and generally vest over a one-year period provided the director continues to serve on the Company's board of directors through the vesting date, except as otherwise provided in the plan. The estimated fair value of options is recognized over the requisite service period, which is generally the vesting period. Share-based compensation expense is based on awards ultimately expected to vest. Forfeitures are estimated based on historical experience at the time of grant and revised in subsequent periods if actual forfeitures differ from those estimates.

The fair value of stock option grants is based on estimates as of the date of grant using a Black-Scholes option valuation model. The Company uses historical data as the basis for estimating option terms and forfeitures. Separate groups of employees that have similar historical stock option exercise and forfeiture behavior are considered separately for valuation purposes. The ranges of expected terms disclosed below reflect different expected behavior among certain groups of employees. Expected stock volatility factors are based on a weighted average of implied volatilities from traded options on the Company's ordinary shares and historical stock price volatility of the Company's ordinary shares, which is determined based on a review of the weighted average of historical daily price changes of the Company's ordinary shares. The risk-free interest rate for periods commensurate with the expected term of the share option is based on the U.S. treasury yield curve in effect at the time of grants. The dividend yield on the Company's ordinary shares is estimated to be zero as the Company has not paid and does not expect to pay dividends. The exercise price of options granted is equal to the closing price of the Company's ordinary shares traded on the NASDAQ Global Select Stock Market on the date of grant.

The fair value of each stock option grant was estimated on the grant date with the following weighted-average assumptions:

Twelve Months Ended

Nine Months Ended

March 31,

December 31, 2013

2013

2012

Expected option term

5 - 7 years

5 - 7 years

5 - 7 years

Expected stock volatility

45% - 48%

47% - 49%

47% - 51%

Risk-free interest rate

0.75% - 2.15%

0.61% - 1.18%

0.82% - 2.5%

Expected annual dividend yield

—

—

—

Time-Vested Restricted Stock Units

Time-vested RSUs awarded to employees generally vest one-fourth per year over four years from the anniversary of the date of grant, provided the employee remains continuously employed with the Company. Shares of the Company's ordinary shares are delivered to the employee upon vesting, subject to payment of applicable withholding taxes. The fair value of time-vested RSUs is equal to the closing price of the Company's ordinary shares traded on the NASDAQ Global Select Stock Market on the date of grant. Compensation expense, including the effect of forfeitures, is recognized over the applicable service period.

Income Taxes

The Company recognizes income taxes under the asset and liability method. Deferred income taxes are recognized for differences between the financial reporting and tax bases of assets and liabilities at enacted statutory tax rates in effect for the years in which the differences are expected to reverse. The effect on deferred taxes of a change in tax rates is recognized in income in the period that includes the enactment date. In evaluating the Company's ability to recover its deferred tax assets, the Company considers all available positive and negative evidence including its past operating results, the existence of cumulative income in the most recent fiscal years, changes in the business in which the Company operates and its forecast of future taxable income. In determining future taxable income, the Company is responsible for assumptions utilized including the amount of Irish, U.S. and other foreign pre-tax operating income, the reversal of temporary differences and the implementation of feasible and prudent tax planning strategies. These assumptions require significant judgment about the forecasts of future taxable income and are consistent with the plans and estimates that the Company is using to manage the underlying businesses.

The Company accounts 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 including, but 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. The Company evaluates this tax position on a quarterly basis. The Company also accrues for potential interest and penalties related to unrecognized tax benefits in income tax expense.

Comprehensive Income (Loss)

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), such as unrealized holding gains and losses on available-for-sale marketable securities and unrealized gains and losses on cash flow hedges.

Earnings (Loss) Per Share

Basic earnings (loss) per share are calculated based upon net income (loss) available to holders of ordinary shares divided by the weighted average number of ordinary shares outstanding. For the calculation of diluted earnings per share, the Company uses the weighted average number of ordinary shares outstanding, as adjusted for the effect of potential dilutive securities, including stock options and RSUs.

Segment Information

The Company operates as one business segment, which is the business of developing, manufacturing and commercializing medicines designed to yield better therapeutic outcomes and improve the lives of patients with serious diseases. The Company's chief decision maker, the Chairman and Chief Executive Officer, reviews the Company's operating results on an aggregate basis and manages the Company's operations as a single operating unit.

Employee Benefit Plans

401(K) Plan

The Company maintains a 401(k) retirement savings plan (the "401(k) Plan"), which covers substantially all of its U.S.-based employees. Eligible employees may contribute up to 100% of their eligible compensation, subject to certain Internal Revenue Service ("IRS") limitations. Through March 31, 2012, the Company matched 50% of the first 6% of employee pay. Beginning April 1, 2012, the Company matches 100% of employee contributions up to the first 5% of employee pay, up to IRS limits. Employee and Company contributions are fully vested when made. During the nine months ended December 31, 2013 and the twelve months ended March 31, 2013 and 2012, the Company contributed $3.1 million, $4.1 million and $2.5 million, respectively, to match employee deferrals under the 401(k) Plan.

Defined Contribution Plan

The Company maintains a defined contribution plan for its Ireland-based employees (the "defined contribution plan"). The defined contribution plan provides for eligible employees to contribute up to the maximum of 40%, depending upon their age, of their total taxable earnings subject to an earnings cap of €115,000. The Company provides a match of up to 18% of taxable earnings depending upon an individual's contribution level. During the nine months ended December 31, 2013 and the twelve months ended March 31, 2013 and 2012, the Company contributed $2.9 million, $3.7 million and $1.8 million, respectively, in contributions to the defined contribution plan.

New 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 the Company as of the specified effective date. Unless otherwise discussed, the Company believes that the impact of recently issued standards that are not yet effective will not have a material impact on its financial position or results of operations upon adoption.

In July 2013, the FASB adopted clarifying guidance on the presentation of unrecognized tax benefits when various qualifying tax credits exist. The amendment requires that unrecognized tax benefits be presented on the consolidated balance sheet as a reduction to deferred tax assets created by net operating losses ("NOLs") or other tax credits from prior periods that occur in the same taxing jurisdiction. To the extent that the unrecognized tax benefit exceeds these NOLs or other tax credits, it shall be presented as a liability. This update is required to be adopted for all annual periods and interim reporting periods beginning after December 15, 2013, with early adoption permitted. The Company does not expect that the adoption of this standard will have a material impact on the presentation of the Company's financial position.

ACQUISITIONS

ACQUISITIONS	9 Months Ended
	Dec. 31, 2013
ACQUISITIONS	'
ACQUISITIONS	'
	3. ACQUISITIONS
	On September 16, 2011, the Company acquired EDT from Elan in a transaction accounted for under the acquisition method of accounting for business combinations, in exchange for $500.0 million in cash and 31.9 million ordinary shares of Alkermes, Inc., valued at $525.1 million, based on a stock price of $16.46 per share on the acquisition date. Under the acquisition method of accounting, the assets acquired and liabilities assumed were recorded as of the acquisition date, at their respective fair values. The reported consolidated financial condition and results of operations after completion of the acquisition reflect these fair values. EDT's results of operations are included in the consolidated financial statements from the date of acquisition.
	Prior to the acquisition, EDT, which was a division of Elan, developed and manufactured pharmaceutical products that deliver clinical benefits to patients using EDT's experience and proprietary drug technologies in collaboration with other pharmaceutical companies worldwide. EDT's two principal drug technology platforms are the oral controlled release platform ("OCR") and the bioavailability enhancement platform, including EDT's NanoCrystal® technology.
	During the year ended March 31, 2012, the Company incurred approximately $29.1 million in expenses related to the EDT acquisition, which primarily consisted of banking, legal, accounting and valuation-related expenses. These expenses have been recorded within "Selling, general and administrative expenses" in the accompanying consolidated statement of operations and comprehensive income (loss). During the year ended March 31, 2012, the Company's results of operations included revenues of $165.0 million and net loss of $6.3 million from the acquired EDT business.
	The purchase price of the EDT business was as follows (in thousands):
	Upfront payment in accordance with the merger agreement	$	500,000
	Equity consideration in accordance with the merger agreement		525,074
	Total purchase price	$	1,025,074
	The purchase price allocation resulted in the following amounts being allocated to the assets acquired and liabilities assumed at the acquisition date based upon their respective fair values, summarized below (in thousands):
	Cash	$	5,225
	Receivables		59,398
	Inventory		29,669
	Prepaid expenses and other current assets		1,806
	Property plant and equipment		210,558
	Acquired identifiable intangible assets		689,000
	Goodwill		92,740
	Other assets		4,360
	Accounts payable and accrued expenses		(18,650	)
	Deferred tax liabilities		(48,448	)
	Other long-term liabilities		(584	)
	Total	$	1,025,074
	Asset categories acquired in the EDT acquisition included working capital, fixed assets and identifiable intangible assets, including IPR&D.
	The intangible assets acquired included the following (in thousands):
	Collaboration agreements	$	499,700
	NanoCrystal technology		74,600
	OCR technology		66,300
	In-process research and development		45,800
	Trademark		2,600
	Total	$	689,000
	On the acquisition date, EDT had several collaboration agreements in place with third-party pharmaceutical companies related to the development and commercialization of a number of products including INVEGA SUSTENNA/XEPLION, AMPYRA/FAMPYRA, TRICOR 145®, RITALIN LA®, FOCALIN® XR. , EMEND® and VERELAN®/VERAPAMIL®. For a complete listing of commercial products utilizing the NanoCrystal technology and Oral Controlled Release technology, including the product indication, collaborative partner, and revenue source, please refer to our "Commercial Products Table" on page 6 of this Transition Report.
	The Company determined the value of each collaboration agreement through the use of the excess earnings method. The Company estimated future revenues to be earned under EDT's collaboration agreements for the remainder of the year ended March 31, 2012 through the fiscal year ending March 31, 2027, and reduced such future revenues by (i) a projected gross margin percentage, (ii) an estimate of operating expenses to be incurred related to these agreements, and (iii) contributory asset charges for working capital and fixed assets. The Company then applied an estimated tax rate, determined based upon the jurisdictions in which the underlying intangible assets are taxed, to arrive at the excess earnings.
	The Company converted the excess earnings attributable to the collaboration agreements to a present value using a discount rate of 14.5%. This discount rate is equal to the Internal Rate of Return ("IRR") the Company calculated as part of the EDT acquisition. The IRR represents the return a market participant would expect to generate through the acquisition of EDT as well as the level of risk reflected in the financial projections used as the basis for the Company's valuation analysis. Based on the valuation performed, the Company estimated its collaboration agreements to have a value on the acquisition date of $499.7 million.
	The Company determined the useful life of the collaboration agreements to be 12 years, which is the Company's best estimate as to the remaining life of the intellectual property for the products underlying the collaboration agreements and the life of the collaboration agreements themselves.
	The Company determined the value of the NanoCrystal and OCR technologies through the use of the income approach, specifically the relief-from-royalty method. The Company estimated the savings in royalties that EDT would otherwise have had to pay if it had not owned the NanoCrystal and OCR technologies and had to license it from a third party with rights of use substantially equivalent to ownership. The Company estimated the present value of the stream of future estimated after-tax royalty payments for the remainder of the year ended March 31, 2012 through the fiscal year ending March 31, 2027. The Company converted the after-tax royalty payments to a present value using the same discount rate of 14.5% as used in the analysis of the collaboration agreements. Based on the valuation performed, the Company estimated its NanoCrystal and OCR technologies to have a value on the acquisition date of $74.6 million and $66.3 million, respectively.
	The Company determined the useful life of the NanoCrystal and OCR technologies to be 13 and 12 years, respectively, which is the Company's best estimate as to the remaining life of the intellectual property.
	Intangible assets associated with IPR&D related to three EDT product candidates. The estimated fair value for the collaboration agreements and IPR&D was determined using the excess earnings approach. The excess earnings approach includes projecting revenue and costs attributable to the associated collaboration agreement or product candidate and then subtracting the required return related to other contributory assets used in the business to determine any residual excess earnings attributable to the collaboration agreement or product candidate. The after-tax excess earnings are then discounted to present value using an appropriate discount rate. During the fourth quarter of fiscal year 2012, and after finalization of the purchase accounting for the Business Combination, the Company identified events and changes in circumstance, such as correspondence from regulatory authorities and further clinical trial results related to the three product candidates acquired as part of the Business Combination, which indicated that the assets may be impaired. Accordingly, the Company recorded an impairment charge of $45.8 million within "Impairment of long-lived assets" in the accompanying statement of operations and comprehensive income (loss). See Note 8, Goodwill and Intangible Assets for additional details.
	The estimated fair value of the EDT trademark was determined using the relief from royalty method. The Company did not expect to use the EDT trademark beyond March 31, 2012 and, as a result, the Company amortized the full value of the trademark during the year ended March 31, 2012.
	The excess of purchase price over the fair value amounts assigned to the assets acquired and liabilities assumed represents the goodwill amount resulting from the acquisition. The Company does not expect any portion of this goodwill to be deductible for tax purposes. The goodwill attributable to the acquisition of EDT has been recorded as a noncurrent asset and is not amortized, but is subject to an annual review for impairment. The factors that contributed to the recognition of goodwill included the synergies that are specific to the Company's business and not available to market participants, including the Company's unique ability to leverage its knowledge in the areas of drug delivery and development of innovative medicines to improve patients' lives, the acquisition of a talented workforce that brings translational medicine expertise to the Company's preclinical compounds and the Company's ability to utilize its research capacity to develop additional compounds using the acquired technologies.
	Pro forma Financial Information (unaudited)
	The following unaudited pro forma information presents the combined results of operations for twelve months ended March 31, 2012 as if the acquisition of EDT had been completed on April 1, 2011. The unaudited pro forma results do not reflect any material adjustments, operating efficiencies or potential cost savings which may result from the consolidation of operations but do reflect certain adjustments expected to have a continuing impact on the combined results.
		Twelve Months Ended
		March 31, 2012
	(In thousands, except per share data)
	Revenues	$	500,105
	Net loss	$	(108,782	)
	Basic and diluted loss per ordinary share	$	(0.84	)

INVESTMENTS

INVESTMENTS	9 Months Ended
	Dec. 31, 2013
INVESTMENTS	'
INVESTMENTS	'
	4. INVESTMENTS
	Investments consist of the following:
				Gross Unrealized
						Losses
	December 31, 2013	Amortized		Gains		Less than			Greater than			Estimated
		Cost				One Year			One Year			Fair Value
		(In thousands)
	Short-term investments:
	Available-for-sale securities:
	U.S. government and agency debt securities	$	130,669	$	80	$	(1	)	$	—		$	130,748
	Corporate debt securities		38,614		64		(30	)		—			38,648
	International government agency debt securities		24,097		8		(33	)		—			24,072
			193,380		152		(64	)		—			193,468
	Money market funds		1,201		—		—			—			1,201
	Total short-term investments		194,581		152		(64	)		—			194,669
	Long-term investments:
	Available-for-sale securities:
	U.S. government and agency debt securities		28,503		—		(61	)		(3	)		28,439
	Equity securities		8,732		21,253		—			—			29,985
	Corporate debt securities		20,266		—		(30	)		(75	)		20,161
	International government agency debt securities		7,691		—		(5	)		—			7,686
			65,192		21,253		(96	)		(78	)		86,271
	Held-to-maturity securities:
	Certificates of deposit		1,493		—		—			—			1,493
	Total long-term investments		66,685		21,253		(96	)		(78	)		87,764
	Total investments	$	261,266	$	21,405	$	(160	)	$	(78	)	$	282,433
	March 31, 2013
	Short-term investments:
	Available-for-sale securities:
	U.S. government and agency debt securities	$	102,093	$	29	$	(1	)	$	—		$	102,121
	Corporate debt securities		10,946		27		—			—			10,973
	International government agency debt securities		10,089		8		(1	)		—			10,096
			123,128		64		(2	)		—			123,190
	Money market funds		1,201		—		—			—			1,201
	Total short-term investments		124,329		64		(2	)		—			124,391
	Long-term investments:
	Available-for-sale securities:
	U.S. government and agency debt securities		60,047		—		(17	)		—			60,030
	Corporate debt securities		18,725		—		(26	)		(162	)		18,537
	International government agency debt securities		3,060		—		—			—			3,060
			81,832		—		(43	)		(162	)		81,627
	Held-to-maturity securities:
	Certificates of deposit		1,200		—		—			—			1,200
	Total long-term investments		83,032		—		(43	)		(162	)		82,827
	Total investments	$	207,361	$	64	$	(45	)	$	(162	)	$	207,218
	The proceeds from the sales and maturities of marketable securities, which were primarily reinvested and resulted in realized gains and losses, were as follows:
				Twelve Months Ended
		Nine Months Ended		March 31,
	(In thousands)	December 31, 2013		2013		2012
	Proceeds from the sales and maturities of marketable securities	$	90,470	$	258,937	$	323,028
	Realized gains	$	16	$	39	$	47
	Realized losses	$	—	$	5	$	11
	The Company's available-for-sale and held-to-maturity securities at December 31, 2013 have contractual maturities in the following periods:
		Available-for-sale				Held-to-maturity
	(In thousands)	Amortized		Estimated		Amortized			Estimated
		Cost		Fair Value		Cost			Fair Value
	Within 1 year	$	107,374	$	107,354	$	1,493		$	1,493
	After 1 year through 5 years		142,466		142,400		—			—
	Total	$	249,840	$	249,754	$	1,493		$	1,493
	At December 31, 2013, the Company believed that the unrealized losses on its available-for-sale investments were temporary. The investments with unrealized losses consisted primarily of corporate debt securities and U.S. Government agency debt securities. In making the determination that the decline in fair value of these securities was temporary, the Company considered various factors, including but not limited to: the length of time each security was in an unrealized loss position; the extent to which fair value was less than cost; financial condition and near-term prospects of the issuers; and the Company's intent not to sell these securities, and the assessment that it is more-likely-than-not that the Company would not be required to sell these securities before the recovery of their amortized cost basis.
	The Company's equity securities at December 31, 2013 included common stock and warrants of Acceleron Pharma, Inc. ("Acceleron"), which the Company accounts for as available-for-sale marketable securities. In September 2013, Acceleron successfully closed on an initial public offering ("IPO") and as a result, the Company's investment in preferred stock was converted to common stock. Prior to the IPO, the Company's investment in Acceleron was accounted for under the cost method as Acceleron was a privately held company over which the Company did not exercise significant influence. The Company's investment in Acceleron was $8.7 million at March 31, 2013 and was included within "Other Assets" in the accompanying consolidated balance sheets.
	The Company's investment in Civitas Therapeutics, Inc. ("Civitas") was $2.0 million and $0.8 million at December 31, 2013 and March 31, 2013, respectively, which was recorded within "Other assets" in the accompanying condensed consolidated balance sheets. In September 2013, the Company invested an additional $1.2 million and converted a promissory note in the amount of $1.2 million into 844,415 shares of Civitas Series B preferred stock. The Company is accounting for its investment in Civitas Series B preferred stock under the cost method of accounting as the Series B preferred stock is not considered to be "in-substance" common stock. The Company is accounting for its investment in Civitas' Series A preferred stock under the equity method as the Series A preferred stock is considered to be "in-substance" common stock and the Company believes it may be able to exercise significant influence over the operating and financial policies of Civitas. During the nine months ended December 31, 2013 and the twelve months ended March 31,2013 and 2012, the Company recorded a reduction in its investment in Civitas of $1.2 million, $1.2 million and $0.8 million, respectively, which represented the Company's proportionate share of Civitas' net losses for these periods. The Company will continue to record its proportionate share of Civitas' net income or loss in future periods.

FAIR_VALUE

FAIR VALUE	9 Months Ended
	Dec. 31, 2013
FAIR VALUE	'
FAIR VALUE	'
	5. FAIR VALUE
	The following table presents information about the Company's assets and liabilities that are measured at fair value on a recurring basis and indicates the fair value hierarchy and the valuation techniques the Company utilized to determine such fair value:
	(In thousands)	December 31,			Level 1		Level 2			Level 3
		2013
	Assets:
	Cash equivalents	$	1,201		$	1,201	$	—		$	—
	U.S. government and agency debt securities		159,187			63,213		95,974			—
	Corporate debt securities		58,809			—		58,809			—
	International government agency debt securities		31,758			—		31,758			—
	Equity securities		29,985			28,459		—			1,526
	Total	$	280,940		$	92,873	$	186,541		$	1,526
	Liabilities:
	Interest rate swap contract	$	(275	)	$	—	$	(275	)	$	—
	Total	$	(275	)	$	—	$	(275	)	$	—
		March 31,			Level 1		Level 2			Level 3
		2013
	Assets:
	Cash equivalents	$	1,201		$	1,201	$	—		$	—
	U.S. government and agency debt securities		162,151			75,025		87,126			—
	Corporate debt securities		29,510			—		29,510			—
	International government agency debt securities		13,156			—		13,156			—
	Total	$	206,018		$	76,226	$	129,792		$	—
	Liabilities:
	Interest rate swap contract	$	(541	)	$	—	$	(541	)	$	—
	Total	$	(541	)	$	—	$	(541	)	$	—
	The Company transfers its financial assets and liabilities, measured at fair value on a recurring basis, between the fair value hierarchies at the end of each reporting period.
	There were no transfers of any securities from Level 1 to Level 2 or from Level 2 to Level 1 during the nine months ended December 31, 2013. The following table is a rollforward of the fair value of the Company's investments whose fair value was determined using Level 3 inputs at December 31, 2013:
	(In thousands)	Fair Value
	Balance, April 1, 2013	$	—
	Conversion of investment from cost method to available-for-sale		807
	Total unrealized gains included in other comprehensive income (loss)		719
	Balance, December 31, 2013	$	1,526
	During the nine months ended December 31, 2013, our Level 3 investment consisted of warrants to purchase the common stock of Acceleron. The Company used a Black-Scholes model to determine the fair value of these warrants. The assumptions used in the Black-Scholes model included the following:
	Current stock price	$	39.6
	Warrant strike price	$	5.88
	Expected term (years)		6.5
	Risk-free rate		2.45	%
	Volatility		70.4	%
	The Company's investments in U.S. government and agency debt securities, international government agency debt securities and corporate debt securities classified as Level 2 were initially valued at the transaction price and subsequently valued, at the end of each reporting period, utilizing market-observable data. The market-observable data include reportable trades, benchmark yields, credit spreads, broker/dealer quotes, bids, offers, current spot rates and other industry and economic events. The Company validates the prices developed using the market-observable data by obtaining market values from other pricing sources, analyzing pricing data in certain instances and confirming that the relevant markets are active.
	The Company entered into an interest rate swap agreement in September 2011 which is described in greater detail in Note 12, Derivative Instruments. The fair value of the Company's interest rate swap agreement was based on an income approach, which excludes accrued interest, and takes into consideration then-current interest rates and the then-current creditworthiness of the Company or the counterparty, as applicable.
	The carrying amounts reflected in the consolidated balance sheets for cash and cash equivalents, accounts receivable, other current assets, accounts payable and accrued expenses approximate fair value due to their short-term nature. The fair value of the remaining financial instruments not currently recognized at fair value on the Company's consolidated balance sheets consists of the $300.0 million, seven-year term loan bearing interest at LIBOR plus 2.75% with a LIBOR floor of 0.75% ("Term Loan B-1") and the $75.0 million, four-year term loan bearing interest at LIBOR plus 2.75%, with no LIBOR floor ("Term Loan B-2" and together with Term Loan B-1, the "Term Loan Facility"). The estimated fair value of these term loans, which was based on quoted market price indications (Level 2 in the fair value hierarchy) and may not be representative of actual values that could have been or will be realized in the future, was as follows at December 31, 2013:
	(In thousands)	Carrying			Estimated
		Value			Fair Value
	Term Loan B-1	$	294,091		$	296,398
	Term Loan B-2	$	70,202		$	70,313

INVENTORY

INVENTORY	9 Months Ended
	Dec. 31, 2013
INVENTORY	'
INVENTORY	'
	6. INVENTORY
	Inventory consists of the following:
	(In thousands)	December 31,		March 31,
		2013		2013
	Raw materials	$	18,410	$	13,506
	Work in process		15,581		13,842
	Finished goods(1)		12,227		16,135
	Total inventory	$	46,218	$	43,483
	-1
	At December 31, 2013 and March 31, 2013, the Company had $1.1 million and $0.6 million, respectively, of finished goods inventory located at its third-party warehouse and shipping service provider.

PROPERTY_PLANT_AND_EQUIPMENT

PROPERTY, PLANT AND EQUIPMENT	9 Months Ended
	Dec. 31, 2013
PROPERTY, PLANT AND EQUIPMENT	'
PROPERTY, PLANT AND EQUIPMENT	'
	7. PROPERTY, PLANT AND EQUIPMENT
	Property, plant and equipment consist of the following:
	(In thousands)	December 31,			March 31,
		2013			2013
	Land	$	8,440		$	8,357
	Building and improvements		148,044			141,092
	Furniture, fixture and equipment		220,984			197,743
	Leasehold improvements		23,980			24,137
	Construction in progress		26,688			39,399
	Subtotal		428,136			410,728
	Less: accumulated depreciation		(153,646	)		(122,293	)
	Total property, plant and equipment, net	$	274,490		$	288,435
	Depreciation expense was $32.3 million, $31.9 million and $22.5 million for the nine months ended December 31, 2013 and the twelve months ended March 31, 2013 and 2012, respectively. Also, during the nine months ended December 31, 2013 and the twelve months ended March 31, 2013, the Company wrote off furniture, fixtures and equipment that had a carrying value of less than $0.1 million at the time of disposition and received proceeds from the sales of furniture, fixtures and equipment of less than $0.1 million.
	During the twelve months ended March 31, 2013, the Company performed an impairment analysis on certain of its manufacturing equipment dedicated to the production of VIVITROL. This equipment was originally purchased by Cephalon in connection with the VIVITROL collaboration and later acquired by the Company upon the termination of the VIVITROL collaboration with Cephalon. The Company determined that these assets will not be used in the future production of VIVITROL and recorded an impairment charge of $3.3 million to write the assets down to their fair value. Fair value was based on the selling prices of the assets.
	Amounts included as construction in progress in the consolidated balance sheets primarily include capital expenditures at the Company's manufacturing facility in Ohio. The Company continues to evaluate its manufacturing capacity based on expectations of demand for its products and will continue to record such amounts within construction in progress until such time as the underlying assets are placed into service. The Company continues to periodically evaluate whether facts and circumstances indicate that the carrying value of its long-lived assets to be held and used may not be recoverable.

GOODWILL_AND_INTANGIBLE_ASSETS

GOODWILL AND INTANGIBLE ASSETS	9 Months Ended
	Dec. 31, 2013
GOODWILL AND INTANGIBLE ASSETS	'
GOODWILL AND INTANGIBLE ASSETS	'
	8. GOODWILL AND INTANGIBLE ASSETS
	Goodwill and intangible assets consists of the following:
				Nine Months Ended December 31,							Twelve Months Ended March 31,
				2013							2013
	(In thousands)	Weighted		Gross		Accumulated			Net Carrying		Gross		Accumulated			Net Carrying
		Amortizable		Carrying		Amortization			Amount		Carrying		Amortization			Amount
		Life		Amount							Amount
	Goodwill			$	92,740	$	—		$	92,740	$	92,740	$	—		$	92,740
	Finite-lived intangible assets:
	Collaboration agreements		12	$	499,700	$	(80,655	)	$	419,045	$	499,700	$	(50,143	)	$	449,557
	NanoCrystal technology		13		74,600		(8,506	)		66,094		74,600		(5,373	)		69,227
	OCR technologies		12		66,300		(13,874	)		52,426		66,300		(9,091	)		57,209
	Total				640,600		(103,035	)		537,565		640,600		(64,607	)		575,993
	During the three months ended December 31, 2013, the Company performed its annual goodwill impairment test. The Company worked with a third-party valuation firm and established fair value for the purpose of impairment testing by using an average of the income approach and the market approach. The income approach employs a discounted cash flow model that takes into account: (i) assumptions that market participants would use in their estimates of fair value; (ii) current period actual results; and (iii) forecasted results for future periods that have been vetted by senior management. The discounted cash flow model incorporates the same fundamental pricing concepts used to calculate fair value in an acquisition due diligence process and a discount rate that takes into consideration the Company's estimated cost of capital adjusted for the uncertainty inherent in an acquisition. The market approach employs market multiples for comparable publicly traded companies in the pharmaceutical and biotechnology industries obtained from industry sources, taking into consideration the nature, scope and size of the acquired reporting unit. In the market approach, estimates of fair value are established using an average of both revenue and EBITDA multiples, adjusted for the reporting unit's performance relative to peer companies.
	At December 31, 2013, the Company's goodwill, which solely relates to the EDT acquisition, was assigned to one reporting unit. The Company determined that the fair value of its reporting unit, subject to the impairment test, was substantially in excess of its respective carrying value and there was no impairment in the value of this asset as of October 31, 2013.
	The Company's finite-lived intangible assets consist of collaborative agreements and the NanoCrystal and OCR technologies acquired as part of the EDT acquisition. The Company recorded $38.4 million, $41.9 million and $25.4 million of amortization expense related to its finite-lived intangible assets during the nine months ended December 31, 2013 and the twelve months ended March 31, 2013 and 2012, respectively. Based on the Company's most recent analysis, amortization of intangible assets included within its condensed consolidated balance sheet at December 31, 2013 is expected to be approximately $60.0 million, $65.0 million, $70.0 million, $70.0 million and $70.0 million in the years ending December 31, 2014 through 2018, respectively. Although the Company believes such available information and assumptions are reasonable, given the inherent risks and uncertainties underlying its expectations regarding such future revenues, there is the potential for the Company's actual results to vary significantly from such expectations. If revenues are projected to change, the related amortization of the intangible assets will change in proportion to the change in revenues.

ACCOUNTS_PAYABLE_AND_ACCRUED_E

ACCOUNTS PAYABLE AND ACCRUED EXPENSES	9 Months Ended
	Dec. 31, 2013
ACCOUNTS PAYABLE AND ACCRUED EXPENSES	'
ACCOUNTS PAYABLE AND ACCRUED EXPENSES	'
	9. ACCOUNTS PAYABLE AND ACCRUED EXPENSES
	Accounts payable and accrued expenses consist of the following:
	(In thousands)	December 31,		March 31,
		2013		2013
	Accounts payable	$	19,493	$	18,282
	Accrued compensation		28,101		30,432
	Accrued restructuring		7,296		602
	Accrued other		36,283		27,594
	Total accounts payable and accrued expenses	$	91,173	$	76,910
	During the three months ended June 30, 2013, the Company recorded a $1.0 million out-of-period adjustment to correct an over-accrued liability from the prior year. The Company believes the impact of this out-of-period adjustment is immaterial to both the previously issued and current period financial statements.

RESTRUCTURING

RESTRUCTURING	9 Months Ended
	Dec. 31, 2013
RESTRUCTURING	'
RESTRUCTURING	'
	10. RESTRUCTURING
	On April 4, 2013, the Company approved a restructuring plan at its Athlone, Ireland manufacturing facility consistent with the evolution of the Company's product portfolio and designed to improve operational performance for the future. The restructuring plan calls for the Company to terminate manufacturing services for certain older products that are expected to no longer be economically practicable to produce due to decreasing demand from its customers resulting from generic competition. The Company expects to continue to generate revenues from the manufacturing of these products into the year ending December 31, 2015.
	As a result of the termination of these services, it was contemplated that the Company will also implement a corresponding reduction in headcount of up to 130 employees. In connection with this restructuring plan, during the twelve months ended March 31, 2013, the Company recorded a restructuring charge of $12.3 million, which consisted of severance and outplacement services. During the nine months ended December 31, 2013, the Company had paid in cash $2.3 million in connection with this restructuring plan and recorded an adjustment to the restructuring accrual due to changes in foreign currency of $0.6 million. Restructuring activity during the nine months ended December 31, 2013 was as follows:
	(In thousands)	Severance and
		Outplacement Services
	Balance, April 1, 2013	$	12,300
	Payments		(2,279	)
	Adjustments		557
	Balance, December 31, 2013	$	10,578
	At December 31, 2013 and March 31, 2013, $6.8 million and none, respectively, of this restructuring accrual were included within "Accounts payable and accrued expenses," and $3.8 million and $12.3 million, respectively, were included within "Other long-term liabilities" in the accompanying consolidated balance sheets.

LONGTERM_DEBT

LONG-TERM DEBT	9 Months Ended
	Dec. 31, 2013
LONG-TERM DEBT	'
LONG-TERM DEBT	'
	11. LONG-TERM DEBT
	Long-term debt consists of the following:
	(In thousands)	December 31,			March 31,
		2013			2013
	Term Loan B-1, due September 25, 2019	$	294,091		$	296,029
	Term Loan B-2, due September 25, 2016		70,202			72,979
	Total		364,293			369,008
	Less: current portion		(6,750	)		(6,750	)
	Long-term debt	$	357,543		$	362,258
	Term Loans
	Term Loan B-1 was issued with a principal balance of $300.0 million, interest payable of LIBOR plus 2.75% with a LIBOR floor of 0.75%, and an original issue discount of $3.0 million. Term Loan B-1 amortizes in equal quarterly amounts of 0.25% of the original principal amount of the loan, with the balance payable at maturity, which is September 25, 2019. Term Loan B-2 was issued with a principal balance of $75.0 million, interest payable of LIBOR plus 2.75% with no LIBOR floor, and an original issue discount of $0.4 million. Term Loan B-2 amortizes in equal quarterly amounts of 1.25% of the original principal amount of the loan, with the balance payable at maturity, which is September 25, 2016. The Term Loan Facility is guaranteed by certain subsidiaries of the Company (the "Guarantors") and is secured by a first priority lien on substantially all of the assets and properties of the Company and the Guarantors (subject to certain exceptions and limitations).
	Scheduled maturities with respect to the Term Loan Facility is as follows (in thousands):
	Year Ended:
	2014	$	6,750
	2015		6,750
	2016		65,813
	2017		3,000
	2018		3,000
	Thereafter		281,250
	Total	$	366,563
	Required quarterly principal payments of $0.8 million on Term Loan B-1 and $0.9 million on Term Loan B-2 began on December 31, 2012. Beginning on January 1, 2014, the Company is subject to mandatory prepayments of principal if certain excess cash flow thresholds, as defined in the Term Loan Facility, are met. The Company may make prepayments of principal without premium or penalty.
	The Term Loan Facility has an incremental facility capacity in an amount of $140.0 million, plus additional amounts as long as the Company meets certain conditions, including a specified leverage ratio. The Term Loan Facility includes a number of restrictive covenants that, among other things and subject to certain exceptions and baskets, impose operating and financial restrictions on the Company and certain of its subsidiaries. The Term Loan Facility also contains customary affirmative covenants and events of default. The Company was in compliance with its debt covenants at December 31, 2013.
	Refinancing and Repricing Transactions
	The Company entered into the Term Loan Facility pursuant to an amendment and restatement, and partial repayment, of its existing long-term debt (such debt, the "2011 Term Loans"). This amendment and restatement represented a restructuring of the 2011 Term Loans (the "Refinancing") and involved multiple lenders who were considered members of a loan syndicate. In determining whether the Refinancing was to be accounted for as a debt extinguishment or modification, the Company considered whether creditors remained the same or changed and whether the change in debt terms was substantial. The terms of the Term Loan Facility were considered substantially different from the 2011 Term Loans if the present value of the cash flows under the Term Loan Facility was at least 10% different from the present value of the remaining cash flows under the 2011 Term Loans (commonly referred to as the "10% Test"). The Company performed a separate 10% Test for each individual creditor participating in the loan syndication. The loans of creditors who did not participate in the Term Loan Facility were accounted for as a debt extinguishment.
	In February 2013, the Company further amended the Term Loan Facility (the "Repricing"). The Repricing was a restructuring of the Term Loan Facility and involved multiple lenders who were considered members of a loan syndicate. The Company performed a similar analysis to the analysis described above to determine if the Repricing was to be accounted for as a debt extinguishment or modification. In addition, since the Repricing occurred within twelve months of the Refinancing, for any lenders who participated in the Refinancing, the Company performed the 10% test using the present value of the remaining cash flows under the Term Loan Facility.
	As the 2011 Term Loans and the Term Loan Facility have a prepayment option exercisable at any time, the Company assumed the prepayment option was exercised immediately on the date of the Refinancing for purposes of applying the 10% Test. When there was a change in principal balance for individual creditors in the Refinancing and/or the Repricing, in applying the 10% Test, the Company used the cash flows related to the lowest common principal balance (commonly referred to as the "Net Method"). Under the Net Method, any principal in excess of a creditor's rollover money was treated as a new, separate debt issuance, and any decrease in principal was treated as a partial extinguishment of debt.
	New costs paid to creditors and third parties in connection with the Refinancing and/or Repricing were allocated to the Term Loan Facility and then further allocated to each creditor. Once these costs were allocated to the individual creditors, an analysis of each creditor was performed and a determination made as to whether the refinancing was accounted for as a debt extinguishment or modification under the 10% Test. For debt considered to be extinguished, the unamortized deferred financing costs and unamortized original issue discount associated with the extinguished debt were expensed. For debt considered to be modified, the unamortized deferred financing costs and unamortized original issue discount associated with the modified debt continue to be amortized, new financing costs were expensed and new third-party fees were capitalized. For new creditors in the Refinancing and/or Repricing, new financing costs and original issue discount fees were capitalized and will be amortized over the estimated repayment period of the new debt.
	The Refinancing and Repricing resulted in a $12.1 million and $7.5 million charge, respectively, in the twelve months ended March 31, 2013, which was included in "Interest expense" in the accompanying consolidated statement of operations and comprehensive income (loss) and was comprised of the following:
	(In thousands)	Sep-12			Feb-13			Total
		Refinancing			Repricing
	Extinguished debt:
	Unamortized deferred financing costs	$	4,600		$	1,566			6,166
	Unamortized original issue discount		2,657			1,437			4,094
	Modified debt:
	Debt financing costs		1,967			805			2,772
	Original issue discount		105			—			105
	Prepayment penalty		2,800			3,733			6,533
	Total	$	12,129		$	7,541			19,670
	At December 31, 2013, the Company's balance of unamortized deferred financing costs and unamortized original issue discount costs were $2.7 million and $2.3 million, respectively. These costs are being amortized to interest expense over the estimated repayment period of the Term Loan Facility using the effective interest method. During the nine months ended December 31, 2013 and the twelve months ended March 31, 2013 and 2012, the Company had amortization expense of $0.8 million, $5.8 million and $3.5 million, respectively, related to deferred financing costs and original issue discount.

DERIVATIVE_INSTRUMENTS

DERIVATIVE INSTRUMENTS	9 Months Ended
	Dec. 31, 2013
DERIVATIVE INSTRUMENTS	'
DERIVATIVE INSTRUMENTS	'
	12. DERIVATIVE INSTRUMENTS
	In December 2011, the Company entered into an interest rate cap agreement with Morgan Stanley Capital Services LLC ("MSCS") at a cost of $0.1 million to mitigate the impact of fluctuations in the three-month LIBOR rate at which the Company's long-term debt bears interest. The interest rate cap agreement expired in December 2013, had a notional value of $160.0 million and was not designated as a hedging instrument. The Company recorded an immaterial amount of loss as "Other income (expense), net" in the accompanying consolidated statements of operations and comprehensive income (loss) due to the decline in value of this contract during the nine months ended December 31, 2013 and the twelve months ended March 31, 2013 and 2012.
	In September 2011, the Company entered into an interest rate cap agreement with HSBC Bank USA at a cost of less than $0.1 million to mitigate the impact of fluctuations in the three-month LIBOR rate at which the Company's long-term debt bears interest. The interest rate cap agreement became effective on September 16, 2011 and expired in December 2012. The interest rate cap agreement had a notional value of $65.0 million and was not designated as a hedging instrument. The Company recorded an immaterial amount of loss within "Other income (expense), net" in the consolidated statements of operations and comprehensive income (loss) due to the decline in value of this contract during the twelve months ended March 31, 2013 and 2012.
	In September 2011, the Company entered into an interest rate swap agreement with MSCS to mitigate the impact of fluctuations in the three-month LIBOR rate at which the Company's long-term debt bears interest. The interest rate swap agreement became effective in December 2012, expires in December 2014 and has a notional value of $65.0 million. This contract was initially designated as a cash flow hedge, however, in connection with the Refinancing, the cash flow hedge was deemed to no longer be effective for accounting purposes. The Company recorded $0.3 million within "Other income (expense), net" due to the decline in fair value of this contract during the nine months ended December 31, 2013. The Company recorded a realized loss of $0.6 million upon the reclassification of unrealized losses to realized losses during the twelve months ended March 31, 2013.
	The following table summarizes the fair value and presentation in the consolidated balance sheets for the Company's hedging instruments (in thousands):
			Fair Value
	(In thousands)	Balance Sheet Location	December 31,			March 31,
			2013			2012
	Interest rate swap
	Liability derivative not designated as a cash flow hedge	Other long-term liabilities	$	(275	)	$	(541	)

EARNINGS_LOSS_PER_SHARE

EARNINGS (LOSS) PER SHARE	9 Months Ended
	Dec. 31, 2013
EARNINGS (LOSS) PER SHARE	'
EARNINGS (LOSS) PER SHARE	'
	13. EARNINGS (LOSS) PER SHARE
	Basic earnings (loss) per ordinary share is calculated based upon net income (loss) available to holders of ordinary shares divided by the weighted average number of shares outstanding. For the calculation of diluted earnings (loss) per ordinary share, the Company uses the weighted average number of ordinary shares outstanding, as adjusted for the effect of potential outstanding shares, including stock options and restricted stock units.
				Twelve Months Ended
		Nine Months		March 31,
		Ended
		December 31,
	(In thousands)	2013		2013		2012
	Numerator:
	Net income (loss)	$	17,649	$	24,983	$	(113,678	)
	Denominator:
	Weighted average number of ordinary shares outstanding		135,960		131,713		114,702
	Effect of dilutive securities:
	Stock options		7,653		4,025		—
	Restricted stock units		1,348		1,362		—
	Dilutive ordinary share equivalents		9,001		5,387		—
	Shares used in calculating diluted earnings (loss) per share		144,961		137,100		114,702
	The following potential ordinary equivalent shares have not been included in the net income (loss) per ordinary share calculations because the effect would have been anti-dilutive:
				Twelve Months
				Ended
		Nine Months		March 31,
		Ended
		December 31,
	(In thousands)	2013		2013		2012
	Stock options		1,404		4,497		8,299
	Restricted stock units		—		—		1,205
	Total		1,404		4,497		9,504

SHAREHOLDERS_EQUITY

SHAREHOLDERS' EQUITY	9 Months Ended
	Dec. 31, 2013
SHAREHOLDERS' EQUITY	'
SHAREHOLDERS' EQUITY	'
	14. SHAREHOLDERS' EQUITY
	Share Repurchase Program
	On September 16, 2011, the board of directors authorized the continuation of the Alkermes, Inc. share repurchase program to repurchase up to $215.0 million of the Company's ordinary shares at the discretion of management from time to time in the open market or through privately negotiated transactions. At December 31, 2013, approximately $101.0 million was available to repurchase ordinary shares pursuant to the repurchase program. All shares repurchased are recorded as treasury stock. The repurchase program has no set expiration date and may be suspended or discontinued at any time. During the nine months ended December 31, 2013 and the twelve months ended March 31, 2013, the Company did not acquire any shares of outstanding ordinary shares under the repurchase program.

SHAREBASED_COMPENSATION

SHARE-BASED COMPENSATION	9 Months Ended
	Dec. 31, 2013
SHARE-BASED COMPENSATION	'
SHARE-BASED COMPENSATION	'
	15. SHARE-BASED COMPENSATION
	Share-based Compensation Expense
	The following table presents share-based compensation expense included in the Company's consolidated statements of operations and comprehensive income (loss):
					Twelve Months
					Ended
		Nine Months			March 31,
		Ended
		December 31,
	(In thousands)	2013			2013		2012
	Cost of goods manufactured and sold	$	3,308		$	4,375	$	2,962
	Research and development		7,799			9,078		8,784
	Selling, general and administrative		22,302			21,263		17,080
	Total share-based compensation expense	$	33,409		$	34,716	$	28,826
	At December 31, 2013 and March 31, 2013 and 2012, $0.4 million, $0.6 million and $0.4 million, respectively, of share-based compensation expense was capitalized and recorded as "Inventory" in the accompanying consolidated balance sheets.
	Share-based Compensation Plans
	The Company has two compensation plans pursuant to which awards are currently being made, the 2011 Stock Option and Incentive Plan (the "2011 Plan"); (ii) and the 2008 Stock Option and Incentive Plan (the "2008 Plan"). The Company has five share-based compensation plans pursuant to which outstanding awards have been made, but from which no further awards can or will be made: (i) the 1996 Stock Option Plan for Non-Employee Directors (the "1996 Plan"); (ii) the 1998 Equity Incentive Plan (the "1998 Plan"); (iii) the 1999 Stock Option Plan (the "1999 Plan"); (iv) the 2002 Restricted Stock Award Plan (the "2002 Plan"); and (v) the 2006 Stock Option Plan for Non-Employee Directors (the "2006 Plan"). The 2011 Plan and the 2008 Plan provides for issuance of non-qualified and incentive stock options, restricted stock, restricted stock units, cash-based awards and performance shares to employees, officers and directors of, and consultants to, the Company in such amounts and with such terms and conditions as may be determined by the compensation committee of the Company's board of directors, subject to provisions of the 2011 Plan and the 2008 Plan.
	At December 31, 2013, there were 10.4 million shares of ordinary shares authorized for issuance under the Company's stock plans. The 2011 Plan provides that awards other than stock options will be counted against the total number of shares available under the plan in a 1.8-to-1 ratio and the 2008 Plan provides that awards other than stock options will be counted against the total number of shares available under the plan in a 2-to-1 ratio.
	Stock Options
	A summary of stock option activity is presented in the following table:
		Number of			Weighted
		Shares			Average
					Exercise Price
	Outstanding, April 1, 2013		16,451,104		$	14.57
	Granted		2,047,250		$	33.52
	Exercised		(3,497,443	)	$	14.26
	Forfeited		(312,750	)	$	19.29
	Expired		(1	)	$	14.62
	Outstanding, December 31, 2013		14,688,160		$	17.18
	Exercisable, December 31, 2013		9,372,735		$	14.54
	The weighted average grant date fair value of stock options granted during the nine months ended December 31, 2013 and the twelve months ended March 31, 2013 and 2012 was $16.27, $8.11 and $8.00, respectively. The aggregate intrinsic value of stock options exercised during the nine months ended December 31, 2013 and the twelve months ended March 31, 2013 and 2012 was $65.6 million, $28.1 million and $11.1 million, respectively.
	At December 31, 2013, there were 5.2 million stock options expected to vest with a weighted average exercise price of $21.73 per share, a weighted average contractual remaining life of 8.3 years and an aggregate intrinsic value of $98.3 million. At December 31, 2013, the aggregate intrinsic value of stock options exercisable was $244.8 million with a weighted average remaining contractual term of 4.9 years. The number of stock options expected to vest is determined by applying the pre-vesting forfeiture rate to the total outstanding options. The intrinsic value of a stock option is the amount by which the market value of the underlying stock exceeds the exercise price of the stock option.
	At December 31, 2013, there was $30.7 million of unrecognized compensation cost related to unvested stock options, which is expected to be recognized over a weighted average period of approximately 2.0 years. Cash received from option exercises under the Company's award plans during the nine months ended December 31, 2013 and the twelve months ended March 31, 2013 and 2012 was $49.1 million, $34.4 million and $20.9 million, respectively.
	Time-Vested Restricted Stock Units
	A summary of time-vested RSU activity is presented in the following table:
		Number of			Weighted
		Shares			Average
					Grant Date
					Fair Value
	Unvested, April 1, 2013		2,226,771		$	15.14
	Granted		770,150		$	33.72
	Vested		(920,021	)	$	13.56
	Forfeited		(89,013	)	$	20.37
	Unvested, December 31, 2013		1,987,887		$	22.83
	The weighted average grant date fair value of time-vested RSUs granted during the nine months ended December 31, 2013 and the twelve months ended March 31, 2013 and 2012 was $33.72, $16.55 and $17.91, respectively. The total fair value of time-vested RSUs that vested during the nine months ended December 31, 2013 and the twelve months ended March 31, 2013, and 2012 was $12.5 million, $9.9 million and $6.1 million, respectively.
	At December 31, 2013, there was $24.7 million of total unrecognized compensation cost related to unvested time-vested RSUs, which will be recognized over a weighted average remaining contractual term of 2.0 years.

COLLABORATIVE_ARRANGEMENTS

COLLABORATIVE ARRANGEMENTS	9 Months Ended
	Dec. 31, 2013
COLLABORATIVE ARRANGEMENTS	'
COLLABORATIVE ARRANGEMENTS	'
	16. COLLABORATIVE ARRANGEMENTS
	The Company's business strategy includes forming collaborations to develop and commercialize its products, and to access technological, financial, marketing, manufacturing and other resources. The Company's significant collaborative arrangements are described below:
	Janssen
	RISPERDAL CONSTA
	Under a product development agreement, the Company collaborated with Janssen on the development of RISPERDAL CONSTA. Under the development agreement, Janssen provided funding to the Company for the development of RISPERDAL CONSTA and Janssen is responsible for securing all necessary regulatory approvals for the product.
	Under license agreements, the Company granted Janssen and an affiliate of Janssen exclusive worldwide licenses to use and sell RISPERDAL CONSTA. Under its license agreements with Janssen, the Company receives royalty payments equal to 2.5% of Janssen's net sales of RISPERDAL CONSTA in each country where the license is in effect based on the quarter when the product is sold by Janssen. This royalty may be reduced in any country based on lack of patent coverage and significant competition from generic versions of the product. Janssen can terminate the license agreements upon 30 days' prior written notice to the Company. Either party may terminate the license agreements by written notice following a breach which continues for 90 days after the delivery of written notice thereof or the other party's insolvency. The licenses granted to Janssen expire on a country-by-country basis upon the later of: (i) the expiration of the last patent claiming the product in such country; or (ii) fifteen years after the date of the first commercial sale of the product in such country, provided that in no event will the license granted to Janssen expire later than the twentieth anniversary of the first commercial sale of the product in such country, with the exception of certain countries where the fifteen-year limitation shall pertain regardless. After expiration, Janssen retains a non-exclusive, royalty-free license to manufacture, use and sell RISPERDAL CONSTA. The Company exclusively manufactures RISPERDAL CONSTA for commercial sale. Under its manufacturing and supply agreement with Janssen, the Company records manufacturing revenues when product is shipped to Janssen, based on 7.5% of Janssen's net unit sales price for RISPERDAL CONSTA for the calendar year.
	The manufacturing and supply agreement terminates on expiration of the license agreements. In addition, either party may terminate the manufacturing and supply agreement upon a material breach by the other party, which is not resolved within 60 days after receipt of a written notice specifying the material breach or upon written notice in the event of the other party's insolvency or bankruptcy. Janssen may terminate the agreement upon six months' written notice to the Company. In the event that Janssen terminates the manufacturing and supply agreement without terminating the license agreements, the royalty rate payable to the Company on Janssen's net sales of RISPERDAL CONSTA would increase from 2.5% to 5.0%.
	Under its agreements with Janssen, the Company recognized manufacturing revenues related to RISPERDAL CONSTA of $82.5 million, $98.6 million and $129.8 million during the nine months ended December 31, 2013 and the twelve months ended March 31, 2013 and 2012, respectively. Under its agreements with Janssen, the Company recognized royalty revenues related to RISPERDAL CONSTA of $24.7 million, $35.0 million and $38.5 million during the nine months ended December 31, 2013 and the twelve months ended March 31, 2013 and 2012, respectively.
	INVEGA SUSTENNA/XEPLION
	Under its license agreement with Janssen Pharmaceutica N.V., the Company granted Janssen a worldwide exclusive license under its NanoCrystal technology to develop, commercialize and manufacture INVEGA SUSTENNA/XEPLION and related products.
	The Company receives certain development milestone payments from Janssen and aggregate tiered royalty payments between 5% and 9% of INVEGA SUSTENNA net sales in each country where the license is in effect, with the exact royalty percentage determined based on worldwide net sales. The tiered royalty payments consist of a patent royalty and a know-how royalty, both of which are determined on a country-by-country basis. The patent royalty, which equals 1.5% of net sales, is payable until the expiration of the last of the patents claiming the product in such country. The know-how royalty is a tiered royalty of 3.5%, 5.5% and 7.5% on aggregate worldwide net sales of below $250.0 million, between $250.0 million and $500.0 million, and greater than $500.0 million, respectively. The know-how royalty is payable for the later of 15 years from first commercial sale of a product in each individual country or March 31, 2019, subject in each case to the expiry of the license agreement. These royalty payments may be reduced in any country based on lack of patent coverage or patent litigation, on competing products achieving certain minimum sales thresholds. The license agreement expires upon the later of: (i) March 31, 2019; or (ii) the expiration of the last of the patents subject to the agreement. After expiration, Janssen retains a non-exclusive, royalty-free license to develop, manufacture and commercialize the products.
	Janssen may terminate the license agreement in whole or in part upon three months' notice to the Company. The Company and Janssen have the right to terminate the agreement upon the material breach of the other party, which is not cured within a certain time period or upon the other party's bankruptcy or insolvency.
	Under its agreements with Janssen, the Company recognized royalty revenues from the sale of INVEGA SUSTENNA/XEPLION of $82.9 million, $63.5 million and $18.0 million during the nine months ended December 31, 2013 and the twelve months ended March 31, 2013 and 2012, respectively.
	Acorda
	Under an amended and restated license agreement, the Company granted Acorda an exclusive worldwide license to use and sell and, solely in accordance with its supply agreement, to make or have made AMPYRA/FAMPYRA. Under its license agreement with Acorda, the Company receives certain commercial and development milestone payments, license revenues and a royalty of approximately 10% based on net sales of AMPYRA/FAMPYRA by Acorda or its sub-licensee, Biogen Idec. This royalty payment may be reduced in any country based on lack of patent coverage, competing products achieving certain minimum sales thresholds and whether Alkermes manufactures the product.
	In June 2009, the Company entered into an amendment of the amended and restated license agreement and the supply agreement with Acorda and, pursuant to such amendment, consented to the sublicense by Acorda to Biogen Idec of Acorda's rights to use and sell FAMPYRA in certain territories outside of the U.S. (to the extent that such rights were to be sublicensed to Biogen Idec pursuant to its separate collaboration and license agreement with Acorda). Under this amendment, the Company agreed to modify certain terms and conditions of the amended and restated license agreement and the supply agreement with Acorda to reflect the sublicense by Acorda to Biogen Idec.
	Acorda has the right to terminate the license agreement upon 90 days' written notice. The Company has the right to terminate the license agreement for countries in which Acorda fails to launch a product within a specified time after obtaining the necessary regulatory approval or fails to file regulatory approvals within a commercially reasonable time after completion of and receipt of positive data from all preclinical and clinical studies required for filing a marketing authorization application. Either party has the right to terminate the license agreement by written notice following a breach of the other party, which is not cured within a certain time period, or upon the other party's entry into bankruptcy or dissolution proceedings. If we terminate Acorda's license in any country, the Company is entitled to a license from Acorda of its patent rights and know-how relating to the product as well as the related data, information and regulatory files, and to market the product in the applicable country, subject to an initial payment equal to Acorda's cost of developing such data, information and regulatory files and to ongoing royalty payments to Acorda. Subject to the termination of the license agreement, licenses granted under the license agreement terminate on a country-by-country basis on the later of: (i) September 2018; or (ii) the expiration of the last to expire of our patents or the existence of a threshold level of competition in the marketplace.
	Under its commercial manufacturing supply agreement with Acorda, the Company manufactures and supplies AMPYRA/FAMPYRA for Acorda (and its sub-licensees). Under the terms of the agreement, Acorda may obtain up to 25% of its total annual requirements of product from a second-source manufacturer. The Company receives royalties equal to 8% of net selling price for all product manufactured by it and a compensating payment for product manufactured and supplied by a third party. The Company may terminate the supply agreement upon 12 months' prior written notice to Acorda and either party may terminate the supply agreement following a material and uncured breach of the supply or license agreement or the entry into bankruptcy or dissolution proceedings by the other party. In addition, subject to early termination of the supply agreement noted above, the supply agreement terminates upon the expiry or termination of the license agreement.
	The Company is entitled to receive the following milestone payments under its amended and restated license agreement with Acorda for each of the third and fourth new indications of the product developed thereunder upon the:
	•
	initiation of a phase 3 clinical trial: $1.0 million;
	•
	acceptance of an NDA by the FDA: $1.0 million;
	•
	approval of the NDA by the FDA: $1.5 million; and
	•
	the first commercial sale: $1.5 million.
	In January 2011, the Company entered into a development and supplemental agreement to its amended and restated license agreement and supply agreement with Acorda. Under the terms of this agreement, the Company granted Acorda the right, either with the Company or with a third party, in each case in accordance with certain terms and conditions, to develop new formulations of dalfampridine or other aminopyridines. Under the terms of the agreement, Acorda has the right to select either a formulation developed by the Company or by a third party for commercialization.
	The Company is entitled to development fees it incurs in developing formulations under the development and supplemental agreement and, if Acorda selects and commercializes any such formulation, to milestone payments (for new indications if not previously paid), license revenues and royalties in accordance with its amended and restated license agreement for the product, and either manufacturing fees as a percentage of net selling price for product manufactured by the Company or compensating fees for product manufactured by third parties.
	If, under the development and supplemental agreement, Acorda selects a formulation not developed by the Company, then the Company will be entitled to various compensation payments and has the first option to manufacture such third-party formulation. The development and supplemental agreement expires upon the expiry or termination of the amended and restated license agreement and may be earlier terminated by either party following an uncured breach of the agreement by the other party.
	Acorda's financial obligations under this development and supplemental agreement continue for a minimum of ten years from the first commercial sale of such new formulation, and may extend for a longer period of time, depending on the intellectual property rights protecting the formulation, regulatory exclusivity and/or the absence of significant market competition. These financial obligations survive termination.
	During the nine months ended December 31, 2013 and the twelve months ended March 31, 2013 and 2012, the Company recognized $51.6 million, $65.0 million and $25.8 million, respectively, of revenues from its arrangements with Acorda.
	AstraZeneca
	In May 2000, we entered into a development and license agreement with Amylin for the development of exendin products falling within the scope of our patents, including the once-weekly formulation of exenatide marketed as BYDUREON. In August 2012, Bristol-Myers Squibb Company ("Bristol-Myers") acquired Amylin. From August 2012 through January 2014, Bristol-Myers and AstraZeneca jointly developed and commercialized Amylin's exendin products, including BYDUREON, through their diabetes collaboration. In April 2013, Bristol-Myers completed its assumption of all global commercialization responsibility related to the marketing of BYDUREON from Amylin's former collaborative partner, Eli Lilly & Company. In February 2014, AstraZeneca acquired sole ownership of the intellectual property and global rights related to BYDUREON and Amylin's other exendin products, including Amylin's rights and obligations under our development and license agreement.
	Pursuant to the development and license agreement, AstraZeneca has an exclusive, worldwide license to the Company's polymer-based microsphere technology for the development and commercialization of injectable extended-release formulations of exendins and other related compounds. The Company receives funding for research and development and will also receive royalty payments based on future product sales. Upon the achievement of certain development and commercialization goals, the Company received milestone payments consisting of cash and warrants for Amylin common stock. In October 2005 and in July 2006, the Company amended the development and license agreement. Under the amended agreement: (i) the Company is responsible for formulation and is principally responsible for non-clinical development of any products that may be developed pursuant to the agreement and for manufacturing these products for use in early-phase clinical trials; and (ii) the Company transferred certain of its technology related to the manufacture of BYDUREON to Amylin and agreed to the manufacture of BYDUREON by Amylin.
	Under the Company's agreement, AstraZeneca is responsible for conducting clinical trials, securing regulatory approvals and commercializing exenatide products, including BYDUREON on a worldwide basis.
	Until December 31, 2021, the Company will receive royalties equal to 8% of net sales from the first 40 million units of BYDUREON sold in any particular calendar year and 5.5% of net sales from units sold beyond the first 40 million units for that calendar year. Thereafter, during the term of the development and license agreement, the Company will receive royalties equal to 5.5% of net sales of products sold. The Company received a $7.0 million milestone payment in July 2011 upon the first commercial sale of BYDUREON in the EU, and the Company received a $7.0 million milestone payment upon the first commercial sale of BYDUREON in the U.S. BYDUREON was launched in the U.S. in February 2012.
	The development and license agreement expires on the later of: (i) 10 years from the first commercial sale of the last of the products covered by the development and license agreement; or (ii) the expiration or invalidation of all of the Company's patents covering such product. Upon expiration, all licenses become non-exclusive and royalty-free. AstraZeneca may terminate the development and license agreement for any reason upon 180 days' written notice to the Company. In addition, either party may terminate the development and license agreement upon a material default or breach by the other party that is not cured within 60 days after receipt of written notice specifying the default or breach. Alkermes may terminate the development and license agreement upon AstraZeneca's insolvency or bankruptcy.
	During the nine months ended December 31, 2013 and the twelve months ended March 31, 2013 and 2012, the Company recognized $20.0 million, $23.8 million and $18.8 million, respectively, of revenues from its arrangements with respect to BYDUREON.

INCOME_TAXES

INCOME TAXES	9 Months Ended
	Dec. 31, 2013
INCOME TAXES	'
INCOME TAXES	'
	17. INCOME TAXES
	The Company's (benefit) provision for income taxes is comprised of the following:
					Twelve Months Ended
		Nine Months			March 31,
		Ended
		December 31,
	(In thousands)	2013			2013			2012
	Current income tax provision (benefit):
	U.S. federal	$	9,224		$	8,152		$	7,321
	U.S. state		2,119			2,588			6,649
	Rest of world		89			1,758			28
	Deferred income tax (benefit) provision:
	Ireland		(3,426	)		(1,961	)		(4,551	)
	U.S. federal		(18,317	)		—			(10,024	)
	U.S. state		(1,941	)		(79	)		(137	)
	Total tax (benefit) provision	$	(12,252	)	$	10,458		$	(714	)
	The current income tax provision for the nine months ended December 31, 2013 and twelve months ended March 31, 2013 was primarily due to U.S. federal and state taxes on income earned by the Company in the U.S. during the fiscal period. An $11.4 million and an $8.9 million benefit were recorded to additional paid-in capital in the nine months ended December 31, 2013 and twelve months ended March 31, 2013, respectively, primarily due to the utilization of current year tax benefits and NOL carryforwards derived from the exercise of employee stock options and vesting of restricted stock units. The current income tax provision for the twelve months ended March 31, 2012 was primarily due to a provision of $13.1 million on the taxable transfer of the BYDUREON intellectual property from the U.S. to Ireland, partially offset by a $4.3 million benefit recorded to additional paid-in capital related to the utilization of certain NOL carryforwards resulting from the exercise of employee stock options.
	The deferred income tax benefit in the nine months ended December 31, 2013 was primarily due to the reversal of a valuation allowance on certain of the Company's U.S. federal and state deferred tax assets. The deferred income tax benefit for the twelve months ended March 31, 2013 was primarily due to the unwind of deferred tax liabilities for intangible assets for which the book basis exceeds the tax basis. These intangible assets are being amortized over the life of the intangible assets. The deferred income tax benefit for the twelve months ended March 31, 2012 was primarily due to the partial release of an existing U.S. federal valuation allowance as a consequence of the Business Combination and a benefit from the partial release of an Irish deferred tax liability relating to acquired intellectual property that was established in connection with the Business Combination.
	No provision for income tax has been provided on undistributed earnings of the Company's foreign subsidiaries because such earnings may be repatriated in a tax efficient manner. Cumulative unremitted earnings of overseas subsidiaries totaled approximately $53.7 million at December 31, 2013.
	The distribution of the Company's income (loss) before the provision for income taxes by geographical area consisted of the following:
					Twelve Months Ended
		Nine Months			March 31,
		Ended
		December 31,
	(In thousands)	2013			2013			2012
	Ireland	$	(63,975	)	$	(14,722	)	$	(36,711	)
	U.S.		49,338			23,503			(84,858	)
	Rest of world		20,034			26,660			7,177
	Income (loss) before provision for income taxes	$	5,397		$	35,441		$	(114,392	)
	The components of the Company's net deferred tax liabilities were as follows:
	(In thousands)	December 31,			March 31,
		2013			2013
	Deferred tax assets:
	Irish NOL carryforwards	$	68,459		$	55,842
	Tax benefit from the exercise of stock options		9,122			8,437
	Share-based compensation		24,353			23,468
	Tax credit carryforwards		6,247			10,543
	Property, plant and equipment		1,912			653
	Bonus accrual		4,585			7,034
	Other		10,538			11,605
	Less: valuation allowance		(69,659	)		(86,714	)
	Total deferred tax assets		55,557			30,868
	Deferred tax liabilities:
	Intangible assets		(38,238	)		(40,968	)
	Property, plant and equipment		(21,571	)		(19,607	)
	Unrealized gains on investments		(7,719	)		—
	Other		(4,421	)		(2,072	)
	Total deferred tax liabilities		(71,949	)		(62,647	)
	Net deferred tax liabilities	$	(16,392	)	$	(31,779	)
	The following table presents the breakdown between current and non-current deferred tax assets (liabilities):
	(In thousands)	December 31,			March 31,
		2013			2013
	Current deferred tax assets	$	12,777		$	5,824
	Non-current deferred tax liabilities		(29,169	)		(37,603	)
	Net deferred tax liabilities	$	(16,392	)	$	(31,779	)
	During the last quarter of the nine months ended December 31, 2013, the Company recognized a benefit of $26.5 million relating to a reversal of a valuation allowance against substantially all of its U.S. federal and state deferred tax assets. The decision to release this valuation allowance was made as the Company determined it was more-likely-than-not that these deferred tax assets would be realized. This decision was based on an assessment of the relative impact of all positive and negative evidence that existed at December 31, 2013, including an evaluation of cumulative income in recent years, a significant positive factor that overcame substantive prior negative evidence. In addition, the Company considered forecasts of future sources of taxable income and significant risks and uncertainties in the business. At December 31, 2013, the Company maintained a valuation allowance of $10.7 million against certain U.S. federal and state deferred tax assets and $58.9 million against certain Irish deferred tax assets as the Company has determined that it is more-likely-than-not that these net deferred tax assets will not be realized. If the Company demonstrates consistent profitability in the future, the evaluation of the recoverability of these deferred tax assets could change and the remaining valuation allowances could be released in part or in whole. $9.1 million of the $10.7 million valuation allowance held against certain U.S. tax assets, when recognized, will be accounted for as a credit to additional paid-in capital rather than a reduction of income tax expense.
	The decrease in the valuation allowance from the twelve months ended March 31, 2013 to the nine months ended December 31, 2013 was primarily related to the reversal of part of the valuation allowance held against the Company's U.S. federal and state deferred tax assets, partially offset by an increase in the valuation allowance held against its Irish deferred tax assets.
	The tax benefit from stock option exercises included in the table above represents benefits accumulated prior to the adoption of Accounting Standards Codification ("ASC") Topic 718 ("ASC 718") that have not been realized. Subsequent to the adoption of ASC 718 on April 1, 2006, an additional $41.1 million of tax benefits from stock option exercises and the vesting of restricted stock units, in the form of NOL carryforwards and tax credit carryforwards, have not been recognized in the financial statements and will be once they are realized. In total, the Company has approximately $50.2 million of tax benefits related to certain NOL carryforwards and tax credit carryforwards resulting from the exercise of employee stock options and the vesting of restricted stock units, which when recognized, will be accounted for as a credit to additional paid-in capital rather than a reduction of income tax expense.
	As of December 31, 2013, the Company had $494.6 million of Irish NOL carryforwards, $77.1 million of U.S. federal NOL carryforwards, $9.8 million of state NOL carryforwards, $22.3 million of federal research and development credits, $7.5 million of alternative minimum tax ("AMT") credits and $0.6 million of state tax credits which will either expire on various dates through 2033 or can be carried forward indefinitely. These loss carryforwards and credits are available to reduce certain future Irish and foreign taxable income, if any. These loss carryforwards and credits are subject to review and possible adjustment by the appropriate taxing authorities. These loss carryforwards and credits, which may be utilized in any future period, may be subject to limitations based upon changes in the ownership of the company's stock. The Company has performed a review of ownership changes in accordance with the U.S. Internal Revenue Code and the Company has determined that it is more-likely-than-not that, as a result of the Business Combination, the Company experienced a change of ownership. As a consequence, the Company's U.S. federal NOL carryforwards and tax credit carryforwards are subject to an annual limitation of $127.0 million.
	A reconciliation of the Company's statutory tax rate to its effective tax rate is as follows:
					Twelve Months
					Ended
		Nine Months			March 31,
Ended
December 31,
	2013			2013			2012
Statutory tax rate		12.5	%		12.5	%		12.5	%
U.S. state income taxes, net of U.S. federal benefit		40.8	%		4.7	%		(6.8	)%
R&D credit		(29.6	)%		(20.5	)%		(8.4	)%
Share-based compensation		13.6	%		3.3	%		(0.7	)%
Non-refundable withholding tax		0.4	%		4.7	%		—	%
Permanent items		(83.6	)%		(8.2	)%		—	%
State tax law change		12.7	%		—	%		—	%
Change in valuation allowance		(321.4	)%		(7.5	)%		55.7	%
Rate differential		127.6	%		40.5	%		(51.7	)%
Effective tax rate		(227.0	)%		29.5	%		0.6	%
The U.S. federal research and development credit has not yet been enacted for 2014 and, unless retroactively reinstated, will cause an increase to the Company's 2014 effective tax rate.
A reconciliation of the beginning and ending amount of unrecognized tax benefits is as follows:
(In thousands)	Unrecognized
	Tax Benefits
Balance, April 1, 2011	$	4,933
Additions based on tax positions related to prior periods		1,741
Decreases due to lapse of statute of limitations		(68	)
Balance, March 31, 2012		6,606
Additions based on tax positions related to prior periods		1,065
Decreases due to settlements with tax authorities		(413	)
Balance, March 31, 2013		7,258
Additions based on tax positions related to prior periods		881
Additions based on tax positions related to the current period		244
Decreases due to lapse of statute of limitations and settlement of prior period uncertain tax positions		(7,258	)
Balance, December 31, 2013	$	1,125
$1.1 million of the unrecognized tax benefits at December 31, 2013, if recognized, would affect the Company's effective tax rate. The Company does not anticipate that the amount of existing unrecognized tax benefits will significantly increase or decrease within the next 12 months. The Company has elected to include interest and penalties related to uncertain tax positions as a component of its provision for taxes. For the nine months ended December 31, 2013 and the twelve months ended March 31, 2013 and 2012, the Company's accrued interest and penalties related to uncertain tax positions were not material.
The Company's major taxing jurisdictions include Ireland and the U.S. (federal and state). These jurisdictions have varying statutes of limitations. In the U.S., the 2011 through 2013 fiscal years remain subject to examination by the respective tax authorities. In Ireland, fiscal years 2009 to 2013 remain subject to examination by the Irish tax authorities. Additionally, because of the Company's Irish and U.S. loss carryforwards and credit carryforwards, certain tax returns from fiscal years 1999 onward may also be examined. These years generally remain open for three to four years after the loss carryforwards have been utilized. During the three months ended June 30, 2013, the IRS completed its review of fiscal years 2007, 2008 and 2010 for Alkermes, Inc. The results of the examination have been reflected in the financial statements. Fiscal year 2012 for Alkermes, Inc. is currently under examination by the Commonwealth of Massachusetts.

TRANSITION_PERIOD_COMPARATIVE_

TRANSITION PERIOD COMPARATIVE DATA	9 Months Ended
	Dec. 31, 2013
TRANSITION PERIOD COMPARATIVE DATA	'
TRANSITION PERIOD COMPARATIVE DATA	'
	18. TRANSITION PERIOD COMPARATIVE DATA
		Nine Months Ended
	(In thousands)	December 31, 2013			December 31, 2012
					(unaudited)
	Statement of Operations Data:
	Revenues	$	432,911		$	412,126
	Operating expenses		417,417			349,297
	Operating income		15,494			62,829
	Other expense (net)		(10,097	)		(35,254	)
	Income before income taxes		5,397			27,575
	Income tax (benefit) provision		(12,252	)		5,591
	Net income	$	17,649		$	21,984
	Earnings per ordinary share—basic	$	0.13		$	0.17
	Earnings per ordinary share—diluted	$	0.12		$	0.16
	Weighted average ordinary shares outstanding—basic		135,960			131,202
	Weighted average ordinary shares outstanding—diluted		144,961			136,216
	Statement of Cash Flows Data:
	Cash flows provided by operations	$	92,221		$	71,247
	Cash flows (used in) provided by investing activities		(65,366	)		43,680
	Cash flows provided by (used in) financing activities		43,746			(62,636	)
	Increase in cash and cash equivalents	$	70,601		$	52,291

COMMITMENTS_AND_CONTINGENCIES

COMMITMENTS AND CONTINGENCIES	9 Months Ended
	Dec. 31, 2013
COMMITMENTS AND CONTINGENCIES	'
COMMITMENTS AND CONTINGENCIES	'
	19. COMMITMENTS AND CONTINGENCIES
	Lease Commitments
	The Company leases certain of its offices, research laboratories and manufacturing facilities under operating leases that expire through the year 2021. Certain of the leases contain provisions for extensions of up to ten years. These lease commitments are primarily related to the Company's corporate headquarters in Ireland and its corporate offices, R&D and manufacturing facilities in Massachusetts. As of December 31, 2013, the total future annual minimum lease payments under the Company's non-cancelable operating leases are as follows:
	(In thousands)	Payment
		Amount
	Year Ended:
	2014	$	4,816
	2015		4,950
	2016		4,281
	2017		4,447
	2018		4,513
	Thereafter		7,409
			30,416
	Less: estimated sublease income		(1,444	)
	Total future minimum lease payments	$	28,972
	Rent expense related to operating leases charged to operations was $3.7 million, $5.0 million and $4.2 million for the nine months ended December 31, 2013 and twelve months ended March 31, 2013 and 2012, respectively. These amounts were net of sublease income of $0.7 million, $2.6 million and $9.2 million, respectively. In addition to its lease commitments, the Company had open purchase orders totaling $101.8 million at December 31, 2013.
	Litigation
	From time to time, the Company may be subject to other legal proceedings and claims in the ordinary course of business. For example, the Company is currently involved in various sets of Paragraph IV litigations in the U.S. and a similar suit in France in respect of certain of its products. The Company is not aware of any such proceedings or claims that it believes will have, individually or in the aggregate, a material adverse effect on its business, financial condition, cash flows and results of operations.

SUBSEQUENT_EVENTS

SUBSEQUENT EVENTS	9 Months Ended
	Dec. 31, 2013
SUBSEQUENT EVENTS	'
SUBSEQUENT EVENTS	'
	20. SUBSEQUENT EVENTS
	In January 2014, the Company sold 5,917,160, $0.01 par value, ordinary shares pursuant to its shelf registration statement on Form S-3 at a price of $42.25 per share. The Company received total gross proceeds of $250 million, before deducting expenses associated with the offering.
	Also, in January 2014, the Company agreed to sell, subject to customary closing conditions, certain of its land, buildings and equipment at its Athlone, Ireland facility. The closing of the acquisition is expected to occur during the first quarter of 2014.

SUMMARY_OF_SIGNIFICANT_ACCOUNT1

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)

9 Months Ended

Dec. 31, 2013

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES

'

Principles of Consolidation

'

Principles of Consolidation

The consolidated financial statements include the accounts of Alkermes plc and its wholly-owned subsidiaries: Alkermes Ireland Holdings Limited; Alkermes Science Three Limited; Alkermes Pharma Ireland Limited; Alkermes Finance Ireland Limited; Alkermes Science One Limited; Alkermes Finance S.à r.l.; Alkermes Finance Ireland (No. 2) Limited; Alkermes U.S. Holdings, Inc.; Alkermes, Inc.; Eagle Holdings USA, Inc.; Alkermes Controlled Therapeutics, Inc.; Alkermes Europe, Ltd.; and Alkermes Gainesville LLC. Intercompany accounts and transactions have been eliminated.

Use of Estimates

'

Use of Estimates

The preparation of the Company's consolidated financial statements in accordance with accounting principles generally accepted in the United States ("U.S.") ("GAAP") requires management to make estimates, judgments and assumptions that may affect the reported amounts of assets, liabilities, revenues and expenses, and related disclosure of contingent assets and liabilities. On an on-going basis, the Company evaluates its estimates and judgments and methodologies, including those related to revenue recognition and related allowances, its collaborative relationships, clinical trial expenses, the valuation of inventory, impairment and amortization of intangibles and long-lived assets, share-based compensation, income taxes including the valuation allowance for deferred tax assets, valuation of investments and derivative instruments, litigation and restructuring charges. The Company bases its estimates on historical experience and on various other assumptions that are believed to be reasonable, the results of which form the basis for making judgments about the carrying values of assets and liabilities. Actual results may differ from these estimates under different assumptions or conditions.

Cash and Cash Equivalents

'

Cash and Cash Equivalents

The Company values its cash and cash equivalents at cost plus accrued interest, which the Company believes approximates their market value. The Company considers only those investments which are highly liquid, readily convertible into cash and so near their maturity, generally three months from the date of purchase, that they present insignificant risk of change in value because of interest rate changes to be cash equivalents.

Investments

'

Investments

The Company has investments in various types of securities, including U.S. government and agency obligations, debt securities issued by foreign agencies and backed by foreign governments, corporate debt securities, and common stock and warrants of a public company with which the Company has a collaborative arrangement. The Company generally holds its interest-bearing investments with major financial institutions and in accordance with documented investment policies. The Company limits the amount of credit exposure to any one financial institution or corporate issuer. At December 31, 2013, substantially all these investments are classified as available-for-sale and are recorded at fair value.

Holding gains and losses on available-for-sale investments are considered "unrealized" and are reported within "Accumulated other comprehensive income (loss)," a component of shareholders' equity. The Company uses the specific identification method for reclassifying unrealized gains and losses into earnings when investments are sold. The Company conducts periodic reviews to identify and evaluate each investment that has an unrealized loss, in accordance with the meaning of other-than-temporary impairment and its application to certain investments, as required by GAAP. An unrealized loss exists when the current fair value of an individual security is less than its amortized cost basis. Unrealized losses on available-for-sale securities that are determined to be temporary, and not related to credit loss, are recorded in accumulated other comprehensive income (loss).

For available-for-sale debt securities with unrealized losses, the Company performs an analysis to assess whether it intends to sell or whether it would more likely than not be required to sell the security before the expected recovery of the amortized cost basis. If the Company intends to sell a security, or may be required to do so, the security's decline in fair value is deemed to be other-than-temporary and the full amount of the unrealized loss is recorded within earnings as an impairment loss. Regardless of the Company's intent to sell a security, the Company performs additional analysis on all securities with unrealized losses to evaluate losses associated with the creditworthiness of the security. Credit losses are identified where the Company does not expect to receive cash flows sufficient to recover the amortized cost basis of a security.

Certain of the Company's money market funds and held-to-maturity investments are restricted investments held as collateral under letters of credit related to certain of the Company's service provider agreements and lease agreements, respectively, and are included in "Investments—short-term" and "Investments—long-term", respectively, in the consolidated balance sheets.

Fair Value of Financial Instruments

'

Fair Value of Financial Instruments

The Company's financial assets and liabilities are recorded at fair value and are classified as Level 1, 2 or 3 within the fair value hierarchy, as described in the accounting standards for fair value measurement. The Company's financial assets and liabilities consist of cash equivalents and investments and are classified within the fair value hierarchy as follows:

Level 1–these valuations are based on a market approach using quoted prices in active markets for identical assets. Valuations of these products do not require a significant degree of judgment. Assets utilizing Level 1 inputs include investments in money market funds, U.S. treasury securities and the common stock of a publicly-traded company;

Level 2–these valuations are based on a market approach using quoted prices obtained from brokers or dealers for similar securities or for securities for which the Company has limited visibility into their trading volumes. Valuations of these financial instruments do not require a significant degree of judgment. Assets and liabilities utilizing Level 2 inputs include U.S. government agency debt securities, debt securities issued by foreign agencies and backed by foreign governments, investments in corporate debt securities that are trading in the credit markets and an interest rate swap contract; and

Level 3–these valuations are based on an income approach using certain inputs that are unobservable and are significant to the overall fair value measurement. Valuations of these products require a significant degree of judgment. During the nine months ended December 31, 2013, the Company's Level 3 investments consisted of warrants to purchase the common stock of a publicly-traded company.

The carrying amounts reflected in the consolidated balance sheets for cash and cash equivalents, accounts receivable, other current assets, accounts payable and accrued expenses approximate fair value due to their short-term nature.

Inventory

'

Inventory

Inventory is stated at the lower of cost or market value. Cost is determined using the first-in, first-out method. Included in inventory are raw materials used in production of pre-clinical and clinical products, which have alternative future use and are charged to R&D expense when consumed.

Property, Plant and Equipment

'

Property, Plant and Equipment

Property, plant and equipment are recorded at cost, subject to review for impairment whenever events or changes in circumstances indicate that the carrying amount of the assets may not be recoverable. Expenditures for repairs and maintenance are charged to expense as incurred and major renewals and improvements are capitalized. Depreciation is calculated using the straight-line method over the following estimated useful lives of the assets:

Asset group

Term

Buildings and improvements

15 - 40 years

Furniture, fixtures and equipment

3 - 10 years

Leasehold improvements

Shorter of useful life or lease term

Goodwill and Intangible Assets

'

Goodwill and Intangible Assets

Goodwill represents the excess cost of the Company's investment in the net assets of acquired companies over the fair value of the underlying identifiable net assets at the date of acquisition. The Company's goodwill, which solely relates to the EDT acquisition in the twelve months ended March 31, 2012, has been assigned to a reporting unit which consists of the former EDT business. A reporting unit is an operating segment or sub-segment to which goodwill is assigned when initially recorded.

Goodwill is not amortized but is reviewed for impairment on an annual basis utilizing a two-step process. The first step requires the Company to compare the fair value of the reporting unit to its respective carrying value, which includes goodwill. If the fair value of the reporting unit exceeds its carrying value, the goodwill is not considered impaired. If the carrying value is higher than the fair value, there is an indication that an impairment may exist and the second step is required. In step two, the implied fair value of goodwill is calculated as the excess of the fair value of a reporting unit over the fair values assigned to its assets and liabilities. If the implied fair value of goodwill is less than the carrying value of the reporting unit's goodwill, the difference is recognized as an impairment loss.

The Company's finite-lived intangible assets consist of core developed technology and collaboration agreements, were recorded at fair value at the time of their acquisition and are stated within the Company's consolidated balance sheets net of accumulated amortization and impairments. The finite-lived intangible assets are amortized over their estimated useful lives using the economic use method, which reflects the pattern that the economic benefits of the intangible assets are consumed as revenue is generated from the underlying patent or contract. The useful lives of the Company's intangible assets are primarily based on the legal or contractual life of the underlying patent or contract, which does not include additional years for the potential extension or renewal of the contract or patent. The Company's intangible assets were all acquired as part of the EDT acquisition in the twelve months ended March 31, 2012, as described in Note 3, Acquisitions.

Impairment of Long-Lived Assets

'

Impairment of Long-Lived Assets

The Company reviews long-lived assets to be held and used for impairment whenever events or changes in circumstances indicate that the carrying amount of the assets may not be recoverable. Conditions that would necessitate an impairment assessment include a significant decline in the observable market value of an asset, a significant change in the extent or manner in which an asset is used, or a significant adverse change that would indicate that the carrying amount of an asset or group of assets is not recoverable. Determination of recoverability is based on an estimate of undiscounted future cash flows resulting from the use of the asset and its eventual disposition. In the event that 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. Long-lived assets to be disposed of are carried at fair value less costs to sell them.

Asset Retirement Obligations

'

Asset Retirement Obligations

The Company recognized an asset retirement obligation for an obligation to remove leasehold improvements and other related activities at the conclusion of the Company's lease for its manufacturing facility located in Chelsea, Massachusetts, which it presently subleases. The carrying amount of the asset retirement obligation at December 31, 2013 and March 31, 2013 was $2.2 million and $2.0 million, respectively, and is included within "Other Long-Term Liabilities" in the accompanying consolidated balance sheets.

The following table shows changes in the carrying amount of the Company's asset retirement obligation at December 31, 2013 and March 31, 2013:

(In thousands)

Carrying

Amount

Balance, April 1, 2012

$

1,862

Accretion expense

187

Balance, March 31, 2013

$

2,049

Accretion expense

151

Balance, December 31, 2013

$

2,200

Revenue Recognition

'

Revenue Recognition

Collaborative Arrangements

The Company has entered into a number of collaboration agreements with pharmaceutical companies including Ortho-McNeil-Janssen Pharmaceuticals, Inc. and Janssen Pharmaceutica International, a division of Cilag International AG ("Janssen") for RISPERDAL® CONSTA® and INVEGA® SUSTENNA®/XEPLION®, Acorda Therapeutics, Inc. ("Acorda") for AMPYRA®/FAMPYRA® and AstraZeneca for BYDUREON® (upon assuming sole responsibility for the development and commercialization of BYDUREON from Bristol-Myers Squibb Company ("Bristol-Myers")). Substantially all of the products developed under the Company's collaborative arrangements are currently being marketed as approved products. The Company receives payments for manufacturing services and/or royalties on product sales.

Manufacturing revenues—The Company recognizes manufacturing revenues from the sale of products it manufactures for resale by its collaborative partners. Manufacturing revenues are recognized when persuasive evidence of an arrangement exists, delivery has occurred and title to the product and associated risk of loss has passed to the customer, the sales price is fixed or determinable and collectability is reasonably assured. The sales price for certain of the Company's manufacturing revenues is based on the end-market sales price earned by its collaborative partners. As the end-market sale occurs after the Company has shipped its product and the risk of loss has passed to its collaborative partner, the Company estimates the sales price for its product based on information supplied to it by the Company's collaborative partners, its historical transaction experience and other third-party data. Differences between the actual manufacturing revenues and estimated manufacturing revenues are reconciled and adjusted for in the period in which they become known, which is generally the following quarter.

Royalty revenues—The Company recognizes royalty revenues related to the sale of products by its collaborative partners that incorporates the Company's technologies. Royalties, with the exception of those from AMPYRA, are earned under the terms of a license agreement in the period the products are sold by the Company's collaborative partner and collectability is reasonably assured. Royalties on AMPYRA are earned in the period the product is shipped to Acorda. Certain of the Company's royalty revenues are recognized by the Company based on information supplied to the Company by its collaborative partners and require estimates to be made. Differences between the actual royalty revenues and estimated royalty revenues are reconciled and adjusted for in the period in which they become known, which is generally the following quarter.

Research and development revenue—R&D revenue consists of funding that compensates the Company for formulation, pre-clinical and clinical testing under R&D arrangements with its collaborative partners. The Company generally bills its collaborative partners under R&D arrangements using a full-time equivalent ("FTE") or hourly rate, plus direct external costs, if any.

Certain of the Company's collaboration agreements entitle it to additional payments upon the achievement of performance-based milestones. If the achievement of a milestone is considered probable at the inception of the collaboration, the related milestone payment is included with other collaboration consideration, such as upfront payments and research funding, in the Company's revenue model. Milestones that involve substantial effort on the Company's part and the achievement of which are not considered probable at the inception of the collaboration are considered "substantive milestones," and are recognized in their entirety in the period in which the milestone is achieved. Consideration received from the achievement of milestones that are not considered to be "substantive milestones" are recognized under the proportional performance method whereby revenue is limited to the lesser of the cumulative amount of payments received or the cumulative amount of revenue earned.

Product Sales, Net

The Company's product sales consist of sales of VIVITROL in the U.S. to wholesalers, specialty distributors and specialty pharmacies. Product sales are recognized from the sale of VIVITROL when persuasive evidence of an arrangement exists, title to the product and associated risk of loss has passed to the customer, which is considered to occur when the product has been received by the customer, the sales price is fixed or determinable and collectability is reasonably assured.

The Company records its product sales net of the following significant categories of sales discounts and allowances as a reduction of product sales at the time VIVITROL is shipped:

•

Medicaid Rebates—the Company records accruals for rebates to states under the Medicaid Drug Rebate Program as a reduction of sales when the product is shipped into the distribution channel. The Company rebates individual states for all eligible units purchased under the Medicaid program based on a rebate per unit calculation, which is based on its Average Manufacturer Price ("AMP"). The Company estimates expected unit sales and rebates per unit under the Medicaid program and adjusts its rebate estimates based on actual unit sales and rebates per unit;

•

Chargebacks—wholesaler and specialty pharmacy chargebacks are discounts that occur when contracted customers purchase directly from an intermediary wholesale purchaser. Contracted customers, which consist primarily of federal government agencies purchasing under the federal supply schedule, generally purchase the product at its contracted price, plus a mark-up from the wholesaler. The wholesaler, in-turn, charges back to the Company the difference between the price initially paid by the wholesaler and the contracted price paid to the wholesaler by the customer. The allowance for chargebacks is based on actual and expected utilization of these programs. Chargebacks could exceed historical experience and the Company's estimates of future participation in these programs. To date, actual chargebacks have not differed materially from the Company's estimates;

•

Product Discounts—cash consideration, including sales incentives, given by us under distribution service agreements with a number of wholesaler, distributor and specialty pharmacy customers that provide them with the opportunity to earn discounts in exchange for the performance of certain services. To date, actual product discounts have not differed materially from the Company's estimates;

•

Co-pay Assistance—the Company has a program whereby a patient can receive up to $500 per month toward their co-payment, co-insurance or deductible, provided the patient meets certain eligibility criteria. Reserves are recorded upon the sale of VIVITROL. To date, actual co-pay assistance has not differed materially from the Company's estimates; and

•

Product Returns—in August 2012, the Company changed the way in which revenue is recognized on VIVITROL product sales. Prior to August 1, 2012, the Company did not have sufficient history to reasonably estimate returns related to VIVITROL shipments and, therefore, the Company deferred the recognition of revenue on shipments of VIVITROL until the product left the distribution channel. In August 2012, it was determined there was sufficient history to reliably estimate returns, and revenue on the sales of VIVITROL is now recognized upon delivery to wholesalers, distributors and pharmacies, which is the point in time the customer assumes the risks and rewards of ownership. This change in the method of revenue recognition resulted in a one-time $1.7 million increase to "Product sales, net" in the accompanying consolidated statements of operations and comprehensive income (loss), which was recognized during the three months ended September 30, 2012.

Based on this revised revenue recognition policy, a reserve is now estimated for future product returns on VIVITROL gross product sales. This estimate is based on historical return rates as well as specifically identified anticipated returns due to known business conditions and product expiry dates. Return amounts are recorded as a deduction to arrive at VIVITROL product sales, net. Once VIVITROL is returned, it is destroyed. At December 31, 2013, the product return reserve was estimated to be approximately 2% of product sales and amounts to $3.8 million.

Risk-Management Instruments

'

Risk-Management Instruments

The Company's derivative activities are initiated within the guidelines of documented corporate risk management policies and do not create additional risk because gains and losses on derivative contracts offset losses and gains on the liabilities being hedged. At December 31, 2013, the Company's risk management instruments consisted of an interest rate swap agreement. The objective of the interest rate swap agreement is to limit the impact of fluctuations in interest rates in earnings related to the Company's long-term debt. The interest rate swap agreement is not designated as a hedging instrument and is recorded at fair value. The associated gains and losses related to the interest rate swap are recognized in "Interest expense" during the period of change. Refer to Note 12, Derivative Instruments, for additional information related to the Company's risk management instruments.

Foreign Currency

'

Foreign Currency

The Company's functional and reporting currency is the U.S. dollar. Transactions in foreign currencies are recorded at the exchange rate prevailing on the date of the transaction. The resulting monetary assets and liabilities are translated into U.S. dollars at exchange rates prevailing on the subsequent balance sheet date. Gains and losses as a result of translation adjustments are recorded within "Other (expense) income, net" in the accompanying consolidated statement of operations and comprehensive income (loss). During the nine months ended December 31, 2013 and the twelve months ended March 31, 2013 and 2012, the Company recorded a gain on foreign currency translation of $0.2 million, $0.1 million and $0.5 million, respectively.

Concentrations

'

Concentrations

Financial instruments that potentially subject the Company to concentrations of credit risk are accounts receivable and marketable securities. Billings to large pharmaceutical and biotechnology companies account for the majority of the Company's accounts receivable, and collateral is generally not required from these customers. To mitigate credit risk, the Company monitors the financial performance and credit worthiness of its customers. The following represents revenue and receivables from the Company's customers exceeding 10% of the total in each category as of December 31, 2013 and March 31, 2013 and 2012, for the nine months ended December 31, 2013 and the twelve months ended March 31, 2013 and 2012:

Twelve Months Ended

Nine Months Ended

March 31,

December 31, 2013

2013

2012

Customer

Receivables

Revenue

Receivables

Revenue

Receivables

Revenue

Janssen

46

%

44

%

32

%

35

%

30

%

48

%

Acorda

12

%

12

%

15

%

11

%

11

%

—

The Company generally holds its interest-bearing investments with major financial institutions, and in accordance with documented investment policies, the Company limits the amount of credit exposure to any one financial institution or corporate issuer. The Company's investment objectives are, first, to assure liquidity and conservation of capital and, second, to obtain investment income.

Geographic Information

'

Geographic Information

Company revenues by geographic location, as determined by the location of the customer, and the location of its assets, are as follows:

Twelve Months Ended

Nine Months Ended

March 31,

(In thousands)

December 31, 2013

2013

2012

Revenue by region:

U.S.

$

269,005

$

380,565

$

212,859

Ireland

5,722

14,455

12,695

Rest of world

158,184

180,528

164,423

Assets by region:

Current assets:

U.S.

$

382,571

$

248,441

$

209,683

Ireland

187,023

159,544

122,077

Rest of world

544

603

7,393

Long-term assets:

U.S.:

Intangible assets

$

—

$

—

$

—

Goodwill

3,677

3,677

3,677

Other

225,559

229,691

213,729

Ireland:

Intangible assets

$

537,565

$

575,993

$

617,845

Goodwill

89,063

89,063

89,063

Other

151,586

163,279

171,750

Research and Development Expenses

'

Research and Development Expenses

For each of its R&D programs, the Company incurs both external and internal expenses. External R&D expenses include costs related to clinical and non-clinical activities performed by contract research organizations, consulting fees, laboratory services, purchases of drug product materials and third-party manufacturing development costs. Internal R&D expenses include employee-related expenses, occupancy costs, depreciation and general overhead. The Company tracks external R&D expenses for each of its development programs, however, internal R&D expenses are not tracked by individual program as they benefit multiple programs or its technologies in general.

Share-Based Compensation

'

Share-Based Compensation

The Company's share-based compensation programs grant awards which include stock options and restricted stock units ("RSUs"), which vest with the passage of time and, to a limited extent, vest based on the achievement of certain performance or market criteria. The Company issues new shares upon stock option exercise or the vesting of RSUs. Certain of the Company's employees are retirement eligible under the terms of the Company's stock option plans (the "Plans"), and stock option awards to these employees generally vest in full upon retirement. Since there are no effective future service requirements for these employees, the fair value of these awards is expensed in full on the grant date or upon meeting the retirement eligibility criteria, whichever is later.

Stock Options

Stock option grants to employees generally expire ten years from the grant date and generally vest one-fourth per year over four years from the anniversary of the date of grant, provided the employee remains continuously employed with the Company, except as otherwise provided in the plan. Stock option grants to directors are for ten-year terms and generally vest over a one-year period provided the director continues to serve on the Company's board of directors through the vesting date, except as otherwise provided in the plan. The estimated fair value of options is recognized over the requisite service period, which is generally the vesting period. Share-based compensation expense is based on awards ultimately expected to vest. Forfeitures are estimated based on historical experience at the time of grant and revised in subsequent periods if actual forfeitures differ from those estimates.

The fair value of stock option grants is based on estimates as of the date of grant using a Black-Scholes option valuation model. The Company uses historical data as the basis for estimating option terms and forfeitures. Separate groups of employees that have similar historical stock option exercise and forfeiture behavior are considered separately for valuation purposes. The ranges of expected terms disclosed below reflect different expected behavior among certain groups of employees. Expected stock volatility factors are based on a weighted average of implied volatilities from traded options on the Company's ordinary shares and historical stock price volatility of the Company's ordinary shares, which is determined based on a review of the weighted average of historical daily price changes of the Company's ordinary shares. The risk-free interest rate for periods commensurate with the expected term of the share option is based on the U.S. treasury yield curve in effect at the time of grants. The dividend yield on the Company's ordinary shares is estimated to be zero as the Company has not paid and does not expect to pay dividends. The exercise price of options granted is equal to the closing price of the Company's ordinary shares traded on the NASDAQ Global Select Stock Market on the date of grant.

The fair value of each stock option grant was estimated on the grant date with the following weighted-average assumptions:

Twelve Months Ended

Nine Months Ended

March 31,

December 31, 2013

2013

2012

Expected option term

5 - 7 years

5 - 7 years

5 - 7 years

Expected stock volatility

45% - 48%

47% - 49%

47% - 51%

Risk-free interest rate

0.75% - 2.15%

0.61% - 1.18%

0.82% - 2.5%

Expected annual dividend yield

—

—

—

Time-Vested Restricted Stock Units

Time-vested RSUs awarded to employees generally vest one-fourth per year over four years from the anniversary of the date of grant, provided the employee remains continuously employed with the Company. Shares of the Company's ordinary shares are delivered to the employee upon vesting, subject to payment of applicable withholding taxes. The fair value of time-vested RSUs is equal to the closing price of the Company's ordinary shares traded on the NASDAQ Global Select Stock Market on the date of grant. Compensation expense, including the effect of forfeitures, is recognized over the applicable service period.

Income Taxes

'

Income Taxes

The Company recognizes income taxes under the asset and liability method. Deferred income taxes are recognized for differences between the financial reporting and tax bases of assets and liabilities at enacted statutory tax rates in effect for the years in which the differences are expected to reverse. The effect on deferred taxes of a change in tax rates is recognized in income in the period that includes the enactment date. In evaluating the Company's ability to recover its deferred tax assets, the Company considers all available positive and negative evidence including its past operating results, the existence of cumulative income in the most recent fiscal years, changes in the business in which the Company operates and its forecast of future taxable income. In determining future taxable income, the Company is responsible for assumptions utilized including the amount of Irish, U.S. and other foreign pre-tax operating income, the reversal of temporary differences and the implementation of feasible and prudent tax planning strategies. These assumptions require significant judgment about the forecasts of future taxable income and are consistent with the plans and estimates that the Company is using to manage the underlying businesses.

The Company accounts 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 including, but 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. The Company evaluates this tax position on a quarterly basis. The Company also accrues for potential interest and penalties related to unrecognized tax benefits in income tax expense.

Comprehensive Income (Loss)

'

Comprehensive Income (Loss)

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), such as unrealized holding gains and losses on available-for-sale marketable securities and unrealized gains and losses on cash flow hedges.

Earnings (Loss) Per Share

'

Earnings (Loss) Per Share

Basic earnings (loss) per share are calculated based upon net income (loss) available to holders of ordinary shares divided by the weighted average number of ordinary shares outstanding. For the calculation of diluted earnings per share, the Company uses the weighted average number of ordinary shares outstanding, as adjusted for the effect of potential dilutive securities, including stock options and RSUs.

Segment Information

'

Segment Information

The Company operates as one business segment, which is the business of developing, manufacturing and commercializing medicines designed to yield better therapeutic outcomes and improve the lives of patients with serious diseases. The Company's chief decision maker, the Chairman and Chief Executive Officer, reviews the Company's operating results on an aggregate basis and manages the Company's operations as a single operating unit.

Employee Benefit Plans

'

Employee Benefit Plans

401(K) Plan

The Company maintains a 401(k) retirement savings plan (the "401(k) Plan"), which covers substantially all of its U.S.-based employees. Eligible employees may contribute up to 100% of their eligible compensation, subject to certain Internal Revenue Service ("IRS") limitations. Through March 31, 2012, the Company matched 50% of the first 6% of employee pay. Beginning April 1, 2012, the Company matches 100% of employee contributions up to the first 5% of employee pay, up to IRS limits. Employee and Company contributions are fully vested when made. During the nine months ended December 31, 2013 and the twelve months ended March 31, 2013 and 2012, the Company contributed $3.1 million, $4.1 million and $2.5 million, respectively, to match employee deferrals under the 401(k) Plan.

Defined Contribution Plan

The Company maintains a defined contribution plan for its Ireland-based employees (the "defined contribution plan"). The defined contribution plan provides for eligible employees to contribute up to the maximum of 40%, depending upon their age, of their total taxable earnings subject to an earnings cap of €115,000. The Company provides a match of up to 18% of taxable earnings depending upon an individual's contribution level. During the nine months ended December 31, 2013 and the twelve months ended March 31, 2013 and 2012, the Company contributed $2.9 million, $3.7 million and $1.8 million, respectively, in contributions to the defined contribution plan.

New Accounting Pronouncements

'

New 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 the Company as of the specified effective date. Unless otherwise discussed, the Company believes that the impact of recently issued standards that are not yet effective will not have a material impact on its financial position or results of operations upon adoption.

In July 2013, the FASB adopted clarifying guidance on the presentation of unrecognized tax benefits when various qualifying tax credits exist. The amendment requires that unrecognized tax benefits be presented on the consolidated balance sheet as a reduction to deferred tax assets created by net operating losses ("NOLs") or other tax credits from prior periods that occur in the same taxing jurisdiction. To the extent that the unrecognized tax benefit exceeds these NOLs or other tax credits, it shall be presented as a liability. This update is required to be adopted for all annual periods and interim reporting periods beginning after December 15, 2013, with early adoption permitted. The Company does not expect that the adoption of this standard will have a material impact on the presentation of the Company's financial position.

SUMMARY_OF_SIGNIFICANT_ACCOUNT2

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Tables)	9 Months Ended
	Dec. 31, 2013
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	'
Schedule of estimated useful life of property, plant and equipment	'
	Asset group	Term
	Buildings and improvements	15 - 40 years
	Furniture, fixtures and equipment	3 - 10 years
	Leasehold improvements	Shorter of useful life or lease term
Schedule of changes in the carrying amount of the company's asset retirement obligation	'
	(In thousands)	Carrying
		Amount
	Balance, April 1, 2012	$	1,862
	Accretion expense		187
	Balance, March 31, 2013	$	2,049
	Accretion expense		151
	Balance, December 31, 2013	$	2,200
Schedule of revenue and receivables from customers exceeding 10% of total in each category	'
								Twelve Months Ended
		Nine Months Ended						March 31,
		December 31, 2013						2013						2012
	Customer	Receivables			Revenue			Receivables			Revenue			Receivables			Revenue
	Janssen		46	%		44	%		32	%		35	%		30	%		48	%
	Acorda		12	%		12	%		15	%		11	%		11	%		—
Schedule of revenues by geographic location, as determined by the location of the customer, and the location of its long-term assets	'
					Twelve Months Ended
		Nine Months Ended			March 31,
	(In thousands)	December 31, 2013			2013			2012
	Revenue by region:
	U.S.	$	269,005		$	380,565		$	212,859
	Ireland		5,722			14,455			12,695
	Rest of world		158,184			180,528			164,423
	Assets by region:
	Current assets:
	U.S.	$	382,571		$	248,441		$	209,683
	Ireland		187,023			159,544			122,077
	Rest of world		544			603			7,393
	Long-term assets:
	U.S.:
	Intangible assets	$	—		$	—		$	—
	Goodwill		3,677			3,677			3,677
	Other		225,559			229,691			213,729
	Ireland:
	Intangible assets	$	537,565		$	575,993		$	617,845
	Goodwill		89,063			89,063			89,063
	Other		151,586			163,279			171,750
Schedule of fair value of each stock option grant estimated on the grant date using weighted-average assumptions	'
				Twelve Months Ended
		Nine Months Ended		March 31,
		December 31, 2013		2013		2012
	Expected option term	5 - 7 years		5 - 7 years		5 - 7 years
	Expected stock volatility	45% - 48%		47% - 49%		47% - 51%
	Risk-free interest rate	0.75% - 2.15%		0.61% - 1.18%		0.82% - 2.5%
	Expected annual dividend yield	—		—		—

ACQUISITIONS_Tables

ACQUISITIONS (Tables)	9 Months Ended
	Dec. 31, 2013
ACQUISITIONS	'
Schedule of purchase price of the EDT business	'
	The purchase price of the EDT business was as follows (in thousands):
	Upfront payment in accordance with the merger agreement	$	500,000
	Equity consideration in accordance with the merger agreement		525,074
	Total purchase price	$	1,025,074
Purchase price allocation of assets acquired and liabilities assumed	'
	The purchase price allocation resulted in the following amounts being allocated to the assets acquired and liabilities assumed at the acquisition date based upon their respective fair values, summarized below (in thousands):
	Cash	$	5,225
	Receivables		59,398
	Inventory		29,669
	Prepaid expenses and other current assets		1,806
	Property plant and equipment		210,558
	Acquired identifiable intangible assets		689,000
	Goodwill		92,740
	Other assets		4,360
	Accounts payable and accrued expenses		(18,650	)
	Deferred tax liabilities		(48,448	)
	Other long-term liabilities		(584	)
	Total	$	1,025,074
Summary of intangible assets acquired	'
	The intangible assets acquired included the following (in thousands):
	Collaboration agreements	$	499,700
	NanoCrystal technology		74,600
	OCR technology		66,300
	In-process research and development		45,800
	Trademark		2,600
	Total	$	689,000
Schedule of unaudited pro forma information	'
		Twelve Months Ended
		March 31, 2012
	(In thousands, except per share data)
	Revenues	$	500,105
	Net loss	$	(108,782	)
	Basic and diluted loss per ordinary share	$	(0.84	)

INVESTMENTS_Tables

INVESTMENTS (Tables)	9 Months Ended
	Dec. 31, 2013
INVESTMENTS	'
Schedule of investments	'
				Gross Unrealized
						Losses
	December 31, 2013	Amortized		Gains		Less than			Greater than			Estimated
		Cost				One Year			One Year			Fair Value
		(In thousands)
	Short-term investments:
	Available-for-sale securities:
	U.S. government and agency debt securities	$	130,669	$	80	$	(1	)	$	—		$	130,748
	Corporate debt securities		38,614		64		(30	)		—			38,648
	International government agency debt securities		24,097		8		(33	)		—			24,072
			193,380		152		(64	)		—			193,468
	Money market funds		1,201		—		—			—			1,201
	Total short-term investments		194,581		152		(64	)		—			194,669
	Long-term investments:
	Available-for-sale securities:
	U.S. government and agency debt securities		28,503		—		(61	)		(3	)		28,439
	Equity securities		8,732		21,253		—			—			29,985
	Corporate debt securities		20,266		—		(30	)		(75	)		20,161
	International government agency debt securities		7,691		—		(5	)		—			7,686
			65,192		21,253		(96	)		(78	)		86,271
	Held-to-maturity securities:
	Certificates of deposit		1,493		—		—			—			1,493
	Total long-term investments		66,685		21,253		(96	)		(78	)		87,764
	Total investments	$	261,266	$	21,405	$	(160	)	$	(78	)	$	282,433
	March 31, 2013
	Short-term investments:
	Available-for-sale securities:
	U.S. government and agency debt securities	$	102,093	$	29	$	(1	)	$	—		$	102,121
	Corporate debt securities		10,946		27		—			—			10,973
	International government agency debt securities		10,089		8		(1	)		—			10,096
			123,128		64		(2	)		—			123,190
	Money market funds		1,201		—		—			—			1,201
	Total short-term investments		124,329		64		(2	)		—			124,391
	Long-term investments:
	Available-for-sale securities:
	U.S. government and agency debt securities		60,047		—		(17	)		—			60,030
	Corporate debt securities		18,725		—		(26	)		(162	)		18,537
	International government agency debt securities		3,060		—		—			—			3,060
			81,832		—		(43	)		(162	)		81,627
	Held-to-maturity securities:
	Certificates of deposit		1,200		—		—			—			1,200
	Total long-term investments		83,032		—		(43	)		(162	)		82,827
	Total investments	$	207,361	$	64	$	(45	)	$	(162	)	$	207,218
Proceeds from the sales and maturities of marketable securities, plus the resulting realized gains and losses	'
				Twelve Months Ended
		Nine Months Ended		March 31,
	(In thousands)	December 31, 2013		2013		2012
	Proceeds from the sales and maturities of marketable securities	$	90,470	$	258,937	$	323,028
	Realized gains	$	16	$	39	$	47
	Realized losses	$	—	$	5	$	11
The cost and fair value of available-for-sale and held-to-maturity securities by contractual maturity	'
		Available-for-sale				Held-to-maturity
	(In thousands)	Amortized		Estimated		Amortized			Estimated
		Cost		Fair Value		Cost			Fair Value
	Within 1 year	$	107,374	$	107,354	$	1,493		$	1,493
	After 1 year through 5 years		142,466		142,400		—			—
	Total	$	249,840	$	249,754	$	1,493		$	1,493

FAIR_VALUE_Tables

FAIR VALUE (Tables)	9 Months Ended
	Dec. 31, 2013
FAIR VALUE	'
Summary of the Company's assets and liabilities measured at fair value on a recurring basis	'
	(In thousands)	December 31,			Level 1		Level 2			Level 3
		2013
	Assets:
	Cash equivalents	$	1,201		$	1,201	$	—		$	—
	U.S. government and agency debt securities		159,187			63,213		95,974			—
	Corporate debt securities		58,809			—		58,809			—
	International government agency debt securities		31,758			—		31,758			—
	Equity securities		29,985			28,459		—			1,526
	Total	$	280,940		$	92,873	$	186,541		$	1,526
	Liabilities:
	Interest rate swap contract	$	(275	)	$	—	$	(275	)	$	—
	Total	$	(275	)	$	—	$	(275	)	$	—
		March 31,			Level 1		Level 2			Level 3
		2013
	Assets:
	Cash equivalents	$	1,201		$	1,201	$	—		$	—
	U.S. government and agency debt securities		162,151			75,025		87,126			—
	Corporate debt securities		29,510			—		29,510			—
	International government agency debt securities		13,156			—		13,156			—
	Total	$	206,018		$	76,226	$	129,792		$	—
	Liabilities:
	Interest rate swap contract	$	(541	)	$	—	$	(541	)	$	—
	Total	$	(541	)	$	—	$	(541	)	$	—
Schedule of rollforward of the fair value of the Company's investments whose fair value was determined using Level 3 inputs	'
	(In thousands)	Fair Value
	Balance, April 1, 2013	$	—
	Conversion of investment from cost method to available-for-sale		807
	Total unrealized gains included in other comprehensive income (loss)		719
	Balance, December 31, 2013	$	1,526
Schedule of assumptions used to determine the fair value of the warrants	'
	During the nine months ended December 31, 2013, our Level 3 investment consisted of warrants to purchase the common stock of Acceleron.
	Current stock price	$	39.6
	Warrant strike price	$	5.88
	Expected term (years)		6.5
	Risk-free rate		2.45	%
	Volatility		70.4	%
Estimated fair value of term loans	'
	The estimated fair value of these term loans, which was based on quoted market price indications (Level 2 in the fair value hierarchy) and may not be representative of actual values that could have been or will be realized in the future, was as follows at December 31, 2013:
	(In thousands)	Carrying			Estimated
		Value			Fair Value
	Term Loan B-1	$	294,091		$	296,398
	Term Loan B-2	$	70,202		$	70,313

INVENTORY_Tables

INVENTORY (Tables)	9 Months Ended
	Dec. 31, 2013
INVENTORY	'
Schedule of inventories	'
	(In thousands)	December 31,		March 31,
		2013		2013
	Raw materials	$	18,410	$	13,506
	Work in process		15,581		13,842
	Finished goods(1)		12,227		16,135
	Total inventory	$	46,218	$	43,483
	-1
	At December 31, 2013 and March 31, 2013, the Company had $1.1 million and $0.6 million, respectively, of finished goods inventory located at its third-party warehouse and shipping service provider.

PROPERTY_PLANT_AND_EQUIPMENT_T

PROPERTY, PLANT AND EQUIPMENT (Tables)	9 Months Ended
	Dec. 31, 2013
PROPERTY, PLANT AND EQUIPMENT	'
Schedule of property, plant and equipment	'
	(In thousands)	December 31,			March 31,
		2013			2013
	Land	$	8,440		$	8,357
	Building and improvements		148,044			141,092
	Furniture, fixture and equipment		220,984			197,743
	Leasehold improvements		23,980			24,137
	Construction in progress		26,688			39,399
	Subtotal		428,136			410,728
	Less: accumulated depreciation		(153,646	)		(122,293	)
	Total property, plant and equipment, net	$	274,490		$	288,435

GOODWILL_AND_INTANGIBLE_ASSETS1

GOODWILL AND INTANGIBLE ASSETS (Tables)	9 Months Ended
	Dec. 31, 2013
GOODWILL AND INTANGIBLE ASSETS	'
Schedule of goodwill and intangible assets	'
				Nine Months Ended December 31,							Twelve Months Ended March 31,
				2013							2013
	(In thousands)	Weighted		Gross		Accumulated			Net Carrying		Gross		Accumulated			Net Carrying
		Amortizable		Carrying		Amortization			Amount		Carrying		Amortization			Amount
		Life		Amount							Amount
	Goodwill			$	92,740	$	—		$	92,740	$	92,740	$	—		$	92,740
	Finite-lived intangible assets:
	Collaboration agreements		12	$	499,700	$	(80,655	)	$	419,045	$	499,700	$	(50,143	)	$	449,557
	NanoCrystal technology		13		74,600		(8,506	)		66,094		74,600		(5,373	)		69,227
	OCR technologies		12		66,300		(13,874	)		52,426		66,300		(9,091	)		57,209
	Total				640,600		(103,035	)		537,565		640,600		(64,607	)		575,993

ACCOUNTS_PAYABLE_AND_ACCRUED_E1

ACCOUNTS PAYABLE AND ACCRUED EXPENSES (Tables)	9 Months Ended
	Dec. 31, 2013
ACCOUNTS PAYABLE AND ACCRUED EXPENSES	'
Schedule of accounts payable and accrued expenses	'
	(In thousands)	December 31,		March 31,
		2013		2013
	Accounts payable	$	19,493	$	18,282
	Accrued compensation		28,101		30,432
	Accrued restructuring		7,296		602
	Accrued other		36,283		27,594
	Total accounts payable and accrued expenses	$	91,173	$	76,910

RESTRUCTURING_Tables

RESTRUCTURING (Tables)	9 Months Ended
	Dec. 31, 2013
RESTRUCTURING	'
Schedule of restructuring charges recorded	'
	(In thousands)	Severance and
		Outplacement Services
	Balance, April 1, 2013	$	12,300
	Payments		(2,279	)
	Adjustments		557
	Balance, December 31, 2013	$	10,578

LONGTERM_DEBT_Tables

LONG-TERM DEBT (Tables)	9 Months Ended
	Dec. 31, 2013
LONG-TERM DEBT	'
Schedule of long-term debt	'
	(In thousands)	December 31,			March 31,
		2013			2013
	Term Loan B-1, due September 25, 2019	$	294,091		$	296,029
	Term Loan B-2, due September 25, 2016		70,202			72,979
	Total		364,293			369,008
	Less: current portion		(6,750	)		(6,750	)
	Long-term debt	$	357,543		$	362,258
Scheduled maturities with respect to the Term Loan Facility	'
	Scheduled maturities with respect to the Term Loan Facility is as follows (in thousands):
	Year Ended:
	2014	$	6,750
	2015		6,750
	2016		65,813
	2017		3,000
	2018		3,000
	Thereafter		281,250
	Total	$	366,563
Schedule of debt refinancing interest expense recognized in condensed consolidated statement of operations and comprehensive income (loss)	'
	(In thousands)	Sep-12			Feb-13			Total
		Refinancing			Repricing
	Extinguished debt:
	Unamortized deferred financing costs	$	4,600		$	1,566			6,166
	Unamortized original issue discount		2,657			1,437			4,094
	Modified debt:
	Debt financing costs		1,967			805			2,772
	Original issue discount		105			—			105
	Prepayment penalty		2,800			3,733			6,533
	Total	$	12,129		$	7,541			19,670

DERIVATIVE_INSTRUMENTS_Tables

DERIVATIVE INSTRUMENTS (Tables)	9 Months Ended
	Dec. 31, 2013
DERIVATIVE INSTRUMENTS	'
Summary of fair value and presentation in the condensed consolidated balance sheets for derivatives designated and not designated as hedging instruments	'
	The following table summarizes the fair value and presentation in the consolidated balance sheets for the Company's hedging instruments (in thousands):
			Fair Value
	(In thousands)	Balance Sheet Location	December 31,			March 31,
			2013			2012
	Interest rate swap
	Liability derivative not designated as a cash flow hedge	Other long-term liabilities	$	(275	)	$	(541	)

EARNINGS_LOSS_PER_SHARE_Tables

EARNINGS (LOSS) PER SHARE (Tables)	9 Months Ended
	Dec. 31, 2013
EARNINGS (LOSS) PER SHARE	'
Schedule of weighted average number of ordinary shares outstanding, as adjusted for the effect of potential outstanding shares, including stock options and restricted stock units	'
				Twelve Months Ended
		Nine Months		March 31,
		Ended
		December 31,
	(In thousands)	2013		2013		2012
	Numerator:
	Net income (loss)	$	17,649	$	24,983	$	(113,678	)
	Denominator:
	Weighted average number of ordinary shares outstanding		135,960		131,713		114,702
	Effect of dilutive securities:
	Stock options		7,653		4,025		—
	Restricted stock units		1,348		1,362		—
	Dilutive ordinary share equivalents		9,001		5,387		—
	Shares used in calculating diluted earnings (loss) per share		144,961		137,100		114,702
Schedule of anti-dilutive potential common equivalent shares excluded from calculation of net (loss) income per share	'
				Twelve Months
				Ended
		Nine Months		March 31,
		Ended
		December 31,
	(In thousands)	2013		2013		2012
	Stock options		1,404		4,497		8,299
	Restricted stock units		—		—		1,205
	Total		1,404		4,497		9,504

SHAREBASED_COMPENSATION_Tables

SHARE-BASED COMPENSATION (Tables)	9 Months Ended
	Dec. 31, 2013
SHARE-BASED COMPENSATION	'
Schedule of share-based compensation expense	'
					Twelve Months
					Ended
		Nine Months			March 31,
		Ended
		December 31,
	(In thousands)	2013			2013		2012
	Cost of goods manufactured and sold	$	3,308		$	4,375	$	2,962
	Research and development		7,799			9,078		8,784
	Selling, general and administrative		22,302			21,263		17,080
	Total share-based compensation expense	$	33,409		$	34,716	$	28,826
Summary of stock option activity	'
		Number of			Weighted
		Shares			Average
					Exercise Price
	Outstanding, April 1, 2013		16,451,104		$	14.57
	Granted		2,047,250		$	33.52
	Exercised		(3,497,443	)	$	14.26
	Forfeited		(312,750	)	$	19.29
	Expired		(1	)	$	14.62
	Outstanding, December 31, 2013		14,688,160		$	17.18
	Exercisable, December 31, 2013		9,372,735		$	14.54
Summary of time-vested RSU activity	'
		Number of			Weighted
		Shares			Average
					Grant Date
					Fair Value
	Unvested, April 1, 2013		2,226,771		$	15.14
	Granted		770,150		$	33.72
	Vested		(920,021	)	$	13.56
	Forfeited		(89,013	)	$	20.37
	Unvested, December 31, 2013		1,987,887		$	22.83

INCOME_TAXES_Tables

INCOME TAXES (Tables)	9 Months Ended
	Dec. 31, 2013
INCOME TAXES	'
Schedule of components of company's (benefit) provision for income taxes	'
					Twelve Months Ended
		Nine Months			March 31,
		Ended
		December 31,
	(In thousands)	2013			2013			2012
	Current income tax provision (benefit):
	U.S. federal	$	9,224		$	8,152		$	7,321
	U.S. state		2,119			2,588			6,649
	Rest of world		89			1,758			28
	Deferred income tax (benefit) provision:
	Ireland		(3,426	)		(1,961	)		(4,551	)
	U.S. federal		(18,317	)		—			(10,024	)
	U.S. state		(1,941	)		(79	)		(137	)
	Total tax (benefit) provision	$	(12,252	)	$	10,458		$	(714	)
Schedule of income (loss) before provision for income taxes by geographical area	'
					Twelve Months Ended
		Nine Months			March 31,
		Ended
		December 31,
	(In thousands)	2013			2013			2012
	Ireland	$	(63,975	)	$	(14,722	)	$	(36,711	)
	U.S.		49,338			23,503			(84,858	)
	Rest of world		20,034			26,660			7,177
	Income (loss) before provision for income taxes	$	5,397		$	35,441		$	(114,392	)
Schedule of components of the company's net deferred tax liabilities	'
	(In thousands)	December 31,			March 31,
		2013			2013
	Deferred tax assets:
	Irish NOL carryforwards	$	68,459		$	55,842
	Tax benefit from the exercise of stock options		9,122			8,437
	Share-based compensation		24,353			23,468
	Tax credit carryforwards		6,247			10,543
	Property, plant and equipment		1,912			653
	Bonus accrual		4,585			7,034
	Other		10,538			11,605
	Less: valuation allowance		(69,659	)		(86,714	)
	Total deferred tax assets		55,557			30,868
	Deferred tax liabilities:
	Intangible assets		(38,238	)		(40,968	)
	Property, plant and equipment		(21,571	)		(19,607	)
	Unrealized gains on investments		(7,719	)		—
	Other		(4,421	)		(2,072	)
	Total deferred tax liabilities		(71,949	)		(62,647	)
	Net deferred tax liabilities	$	(16,392	)	$	(31,779	)
Schedule of current and non-current deferred tax assets (liabilities)	'
	(In thousands)	December 31,			March 31,
		2013			2013
	Current deferred tax assets	$	12,777		$	5,824
	Non-current deferred tax liabilities		(29,169	)		(37,603	)
	Net deferred tax liabilities	$	(16,392	)	$	(31,779	)
Schedule of reconciliation of the company's federal statutory tax rate to its effective tax rate	'
					Twelve Months
					Ended
		Nine Months			March 31,
		Ended
		December 31,
		2013			2013			2012
	Statutory tax rate		12.5	%		12.5	%		12.5	%
	U.S. state income taxes, net of U.S. federal benefit		40.8	%		4.7	%		(6.8	)%
	R&D credit		(29.6	)%		(20.5	)%		(8.4	)%
	Share-based compensation		13.6	%		3.3	%		(0.7	)%
	Non-refundable withholding tax		0.4	%		4.7	%		—	%
	Permanent items		(83.6	)%		(8.2	)%		—	%
	State tax law change		12.7	%		—	%		—	%
	Change in valuation allowance		(321.4	)%		(7.5	)%		55.7	%
	Rate differential		127.6	%		40.5	%		(51.7	)%
	Effective tax rate		(227.0	)%		29.5	%		0.6	%
Schedule of reconciliation of the beginning and ending amount of unrecognized tax benefits	'
	(In thousands)	Unrecognized
		Tax Benefits
	Balance, April 1, 2011	$	4,933
	Additions based on tax positions related to prior periods		1,741
	Decreases due to lapse of statute of limitations		(68	)
	Balance, March 31, 2012		6,606
	Additions based on tax positions related to prior periods		1,065
	Decreases due to settlements with tax authorities		(413	)
	Balance, March 31, 2013		7,258
	Additions based on tax positions related to prior periods		881
	Additions based on tax positions related to the current period		244
	Decreases due to lapse of statute of limitations and settlement of prior period uncertain tax positions		(7,258	)
	Balance, December 31, 2013	$	1,125

TRANSITION_PERIOD_COMPARATIVE_1

TRANSITION PERIOD COMPARATIVE DATA (Tables)	9 Months Ended
	Dec. 31, 2013
TRANSITION PERIOD COMPARATIVE DATA	'
Schedule of transition period comparative data	'
		Nine Months Ended
	(In thousands)	December 31, 2013			December 31, 2012
					(unaudited)
	Statement of Operations Data:
	Revenues	$	432,911		$	412,126
	Operating expenses		417,417			349,297
	Operating income		15,494			62,829
	Other expense (net)		(10,097	)		(35,254	)
	Income before income taxes		5,397			27,575
	Income tax (benefit) provision		(12,252	)		5,591
	Net income	$	17,649		$	21,984
	Earnings per ordinary share—basic	$	0.13		$	0.17
	Earnings per ordinary share—diluted	$	0.12		$	0.16
	Weighted average ordinary shares outstanding—basic		135,960			131,202
	Weighted average ordinary shares outstanding—diluted		144,961			136,216
	Statement of Cash Flows Data:
	Cash flows provided by operations	$	92,221		$	71,247
	Cash flows (used in) provided by investing activities		(65,366	)		43,680
	Cash flows provided by (used in) financing activities		43,746			(62,636	)
	Increase in cash and cash equivalents	$	70,601		$	52,291

COMMITMENTS_AND_CONTINGENCIES_

COMMITMENTS AND CONTINGENCIES (Tables)	9 Months Ended
	Dec. 31, 2013
COMMITMENTS AND CONTINGENCIES	'
Schedule of future minimum rental commitments under non-cancelable operating leases	'
	As of December 31, 2013, the total future annual minimum lease payments under the Company's non-cancelable operating leases are as follows:
	(In thousands)	Payment
		Amount
	Year Ended:
	2014	$	4,816
	2015		4,950
	2016		4,281
	2017		4,447
	2018		4,513
	Thereafter		7,409
			30,416
	Less: estimated sublease income		(1,444	)
	Total future minimum lease payments	$	28,972

DESCRIPTION_OF_BUSINESS_AND_BA1

DESCRIPTION OF BUSINESS AND BASIS OF PRESENTATION (Details)	9 Months Ended
	Dec. 31, 2013
	product
DESCRIPTION OF BUSINESS AND BASIS OF PRESENTATION	'
Minimum number of commercial drug products in Company's diversified portfolio	20

SUMMARY_OF_SIGNIFICANT_ACCOUNT3

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details) (USD $)	9 Months Ended	12 Months Ended
	Dec. 31, 2013	Mar. 31, 2013
Asset Retirement Obligations	'	'
Asset retirement obligation	$2,200,000	$2,000,000
Changes in the carrying amount of the company's asset retirement obligation	'	'
Balance at the beginning of the period	2,049,000	1,862,000
Accretion expense	151,000	187,000
Balance at the end of the period	$2,200,000	$2,049,000
Buildings and improvements | Minimum	'	'
Property, plant and equipment	'	'
Estimated useful life	'15 years	'
Buildings and improvements | Maximum	'	'
Property, plant and equipment	'	'
Estimated useful life	'40 years	'
Furniture, fixtures and equipment | Minimum	'	'
Property, plant and equipment	'	'
Estimated useful life	'3 years	'
Furniture, fixtures and equipment | Maximum	'	'
Property, plant and equipment	'	'
Estimated useful life	'10 years	'

SUMMARY_OF_SIGNIFICANT_ACCOUNT4

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details 2) (USD $)	3 Months Ended	9 Months Ended	12 Months Ended
	Sep. 30, 2012	Dec. 31, 2013	Mar. 31, 2013	Mar. 31, 2012
Revenue Recognition	'	'	'	'
Maximum monthly co-pay assistance	'	$500	'	'
Increase in product sales, net	1,700,000	'	'	'
Product return reserve as percentage of product sales	'	2.00%	'	'
Product return reserve	'	3,800,000	'	'
Foreign Currency	'	'	'	'
Gain on foreign currency translation	'	$200,000	$100,000	$500,000

SUMMARY_OF_SIGNIFICANT_ACCOUNT5

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details 3)	9 Months Ended	12 Months Ended
	Dec. 31, 2013	Mar. 31, 2013	Mar. 31, 2012
Receivables | Janssen	'	'	'
Concentrations	'	'	'
Concentration risk percentage	46.00%	32.00%	30.00%
Receivables | Acorda	'	'	'
Concentrations	'	'	'
Concentration risk percentage	12.00%	15.00%	11.00%
Revenue | Janssen	'	'	'
Concentrations	'	'	'
Concentration risk percentage	44.00%	35.00%	48.00%
Revenue | Acorda	'	'	'
Concentrations	'	'	'
Concentration risk percentage	12.00%	11.00%	'
Accounts receivable	'	'	'
Concentrations	'	'	'
Threshold percentage for disclosure of revenue and receivables	10.00%	10.00%	10.00%
Revenues, net	'	'	'
Concentrations	'	'	'
Threshold percentage for disclosure of revenue and receivables	10.00%	10.00%	10.00%

SUMMARY_OF_SIGNIFICANT_ACCOUNT6

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details 4) (USD $)	9 Months Ended	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Mar. 31, 2013	Mar. 31, 2012
Geographic Information	'	'	'
Current assets:	$570,138	$408,588	'
Long-term assets:	'	'	'
Intangible assets	537,565	575,993	'
Goodwill	92,740	92,740	'
Other	14,891	21,708	'
United States	'	'	'
Geographic Information	'	'	'
Revenue by region:	269,005	380,565	212,859
Current assets:	382,571	248,441	209,683
Long-term assets:	'	'	'
Goodwill	3,677	3,677	3,677
Other	225,559	229,691	213,729
Ireland	'	'	'
Geographic Information	'	'	'
Revenue by region:	5,722	14,455	12,695
Current assets:	187,023	159,544	122,077
Long-term assets:	'	'	'
Intangible assets	537,565	575,993	617,845
Goodwill	89,063	89,063	89,063
Other	151,586	163,279	171,750
Rest of world	'	'	'
Geographic Information	'	'	'
Revenue by region:	158,184	180,528	164,423
Current assets:	$544	$603	$7,393

SUMMARY_OF_SIGNIFICANT_ACCOUNT7

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details 5)	9 Months Ended	12 Months Ended
	Dec. 31, 2013	Mar. 31, 2013	Mar. 31, 2012
Stock options	'	'	'
Share-based compensation	'	'	'
Expiration period	'10 years	'	'
Vesting rights per year (as a percent)	25.00%	'	'
Vesting period	'4 years	'	'
Weighted-average assumptions	'	'	'
Expected stock volatility, minimum (as a percent)	45.00%	47.00%	47.00%
Expected stock volatility, maximum (as a percent)	48.00%	49.00%	51.00%
Risk-free interest rate, minimum (as a percent)	0.75%	0.61%	0.82%
Risk-free interest rate, maximum (as a percent)	2.15%	1.18%	2.50%
Expected annual dividend yield (as a percent)	0.00%	'	'
Stock options | Minimum	'	'	'
Weighted-average assumptions	'	'	'
Expected option term	'5 years	'5 years	'5 years
Stock options | Maximum	'	'	'
Weighted-average assumptions	'	'	'
Expected option term	'7 years	'7 years	'7 years
Stock options | Directors	'	'	'
Share-based compensation	'	'	'
Expiration period	'10 years	'	'
Vesting period	'1 year	'	'
Time-vested RSUs	'	'	'
Share-based compensation	'	'	'
Vesting rights per year (as a percent)	25.00%	'	'
Vesting period	'4 years	'	'

SUMMARY_OF_SIGNIFICANT_ACCOUNT8

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details 6)	12 Months Ended	0 Months Ended	9 Months Ended	12 Months Ended		9 Months Ended		12 Months Ended
	Mar. 31, 2013	Apr. 02, 2012	Dec. 31, 2013	Mar. 31, 2013	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2013	Mar. 31, 2013	Mar. 31, 2012
	item	401 (K) Plan	401 (K) Plan	401 (K) Plan	401 (K) Plan	Defined Contribution Plan	Defined Contribution Plan	Defined Contribution Plan	Defined Contribution Plan
		United States	United States	United States	United States	USD ($)	EUR (€)	USD ($)	USD ($)
			USD ($)	USD ($)	USD ($)
Segment Information	'	'	'	'	'	'	'	'	'
Number of business segments	1	'	'	'	'	'	'	'	'
Employee benefit plans	'	'	'	'	'	'	'	'	'
Employee contribution limit as a percentage of their eligible compensation	'	'	100.00%	100.00%	'	'	'	'	'
Percentage of employer contribution matched of the first employee pay	'	100.00%	'	'	50.00%	'	'	'	'
Percentage of employee pay matched by the employer	'	'	'	'	6.00%	'	'	'	'
Maximum percentage of employer contribution matched of employee's	'	'	'	'	'	18.00%	18.00%	'	'
Employer contribution	'	'	$3,100,000	$4,100,000	$2,500,000	$2,900,000	'	$3,700,000	$1,800,000
Maximum employee contribution limit as a percentage of their total taxable earnings	'	5.00%	'	'	'	40.00%	40.00%	'	'
Per employee contribution limit	'	'	'	'	'	'	€ 115,000	'	'

ACQUISITIONS_Details

ACQUISITIONS (Details) (USD $)	12 Months Ended	0 Months Ended	12 Months Ended
Share data in Millions, except Per Share data, unless otherwise specified	Mar. 31, 2013	Sep. 16, 2011	Mar. 31, 2012
	item	EDT	EDT
ACQUISITIONS	'	'	'
Number of principal drug technology platforms	2	'	'
Acquisitions	'	'	'
Cash paid for acquisition	'	$500,000,000	'
Ordinary shares issued as consideration in the acquisition	'	31.9	'
Value of ordinary shares issued as consideration in the acquisition	'	525,100,000	'
Closing stock price (in dollars per share)	'	$16.46	'
Expenses related to acquisition	'	'	29,100,000
Revenues from acquired business	'	'	165,000,000
Net loss from acquired business	'	'	($6,300,000)

ACQUISITIONS_Details_2

ACQUISITIONS (Details 2) (USD $)	Dec. 31, 2013	Mar. 31, 2013	Sep. 16, 2011
In Thousands, unless otherwise specified			EDT
Purchase price of the EDT business	'	'	'
Upfront payment in accordance with the merger agreement	'	'	$500,000
Equity consideration in accordance with the merger agreement	'	'	525,074
Total purchase price	'	'	1,025,074
Purchase price allocation of assets acquired and liabilities assumed	'	'	'
Cash	'	'	5,225
Receivables	'	'	59,398
Inventory	'	'	29,669
Prepaid expenses and other current assets	'	'	1,806
Property plant and equipment	'	'	210,558
Acquired identifiable intangible assets	'	'	689,000
Goodwill	92,740	92,740	92,740
Other assets	'	'	4,360
Accounts payable and accrued expenses	'	'	-18,650
Deferred tax liabilities	'	'	-48,448
Other long-term liabilities	'	'	-584
Total	'	'	$1,025,074

ACQUISITIONS_Details_3

ACQUISITIONS (Details 3) (EDT, USD $)	0 Months Ended	12 Months Ended
	Sep. 16, 2012	Mar. 31, 2013
		item
Intangible assets acquired	'	'
Intangible assets acquired, finite-lived	$689,000,000	'
In-process research and development	'	'
Intangible assets acquired	'	'
Intangible assets acquired, indefinite-lived	45,800,000	'
Impairment charge	'	45,800,000
Number of products	'	3
Collaboration agreements	'	'
Intangible assets acquired	'	'
Intangible assets acquired, finite-lived	499,700,000	'
Estimated useful life of intangible assets acquired	'	'12 years
Discount rate (as a percent)	'	14.50%
NanoCrystal technology	'	'
Intangible assets acquired	'	'
Intangible assets acquired, finite-lived	74,600,000	'
Estimated useful life of intangible assets acquired	'	'13 years
Discount rate (as a percent)	'	14.50%
OCR technologies	'	'
Intangible assets acquired	'	'
Intangible assets acquired, finite-lived	66,300,000	'
Estimated useful life of intangible assets acquired	'	'12 years
Discount rate (as a percent)	'	14.50%
Trademark	'	'
Intangible assets acquired	'	'
Intangible assets acquired, finite-lived	$2,600,000	'

ACQUISITIONS_Details_4

ACQUISITIONS (Details 4) (EDT, USD $)	12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Mar. 31, 2012
EDT	'
Unaudited pro forma information	'
Revenues	$500,105
Net loss	($108,782)
Basic and diluted (loss) per ordinary share	($0.84)

INVESTMENTS_Details

INVESTMENTS (Details) (USD $)	9 Months Ended	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Mar. 31, 2013
Held-to-maturity securities:	'	'
Estimated Fair Value	$1,493	'
Total investments	'	'
Amortized Cost	261,266	207,361
Gross Unrealized Gains	21,405	64
Gross Unrealized Losses, Less than One Year	-160	-45
Gross Unrealized Losses, Greater than One Year	-78	-162
Estimated Fair Value	282,433	207,218
Short-term investments	'	'
Available-for-sale securities:	'	'
Amortized Cost	193,380	123,128
Gross Unrealized Gains	152	64
Gross Unrealized Losses, Less than One Year	-64	-2
Estimated Fair Value	193,468	123,190
Total investments	'	'
Amortized Cost	194,581	124,329
Gross Unrealized Gains	152	64
Gross Unrealized Losses, Less than One Year	-64	-2
Estimated Fair Value	194,669	124,391
Short-term investments | Money market funds	'	'
Total investments	'	'
Amortized Cost	1,201	1,201
Estimated Fair Value	1,201	1,201
Short-term investments | U.S. government and agency debt securities	'	'
Available-for-sale securities:	'	'
Amortized Cost	130,669	102,093
Gross Unrealized Gains	80	29
Gross Unrealized Losses, Less than One Year	-1	-1
Estimated Fair Value	130,748	102,121
Short-term investments | Corporate debt securities	'	'
Available-for-sale securities:	'	'
Amortized Cost	38,614	10,946
Gross Unrealized Gains	64	27
Gross Unrealized Losses, Less than One Year	-30	'
Estimated Fair Value	38,648	10,973
Short-term investments | International government agency debt securities	'	'
Available-for-sale securities:	'	'
Amortized Cost	24,097	10,089
Gross Unrealized Gains	8	8
Gross Unrealized Losses, Less than One Year	-33	-1
Estimated Fair Value	24,072	10,096
Long-term investments	'	'
Available-for-sale securities:	'	'
Amortized Cost	65,192	81,832
Gross Unrealized Gains	21,253	'
Gross Unrealized Losses, Less than One Year	-96	-43
Gross Unrealized Losses, Greater than One Year	-78	-162
Estimated Fair Value	86,271	81,627
Held-to-maturity securities:	'	'
Amortized Cost	66,685	83,032
Gross Unrealized Gains	21,253	'
Gross Unrealized Losses, Less than One Year	-96	-43
Gross Unrealized Losses, Greater than One Year	-78	-162
Estimated Fair Value	87,764	82,827
Long-term investments | Certificates of deposit	'	'
Held-to-maturity securities:	'	'
Amortized Cost	1,493	1,200
Estimated Fair Value	1,493	1,200
Long-term investments | U.S. government and agency debt securities	'	'
Available-for-sale securities:	'	'
Amortized Cost	28,503	60,047
Gross Unrealized Losses, Less than One Year	-61	-17
Gross Unrealized Losses, Greater than One Year	-3	'
Estimated Fair Value	28,439	60,030
Long-term investments | Corporate debt securities	'	'
Available-for-sale securities:	'	'
Amortized Cost	20,266	18,725
Gross Unrealized Losses, Less than One Year	-30	-26
Gross Unrealized Losses, Greater than One Year	-75	-162
Estimated Fair Value	20,161	18,537
Long-term investments | Equity securities	'	'
Available-for-sale securities:	'	'
Amortized Cost	8,732	'
Gross Unrealized Gains	21,253	'
Estimated Fair Value	29,985	'
Long-term investments | International government agency debt securities	'	'
Available-for-sale securities:	'	'
Amortized Cost	7,691	3,060
Gross Unrealized Losses, Less than One Year	-5	'
Estimated Fair Value	$7,686	$3,060

INVESTMENTS_Details_2

INVESTMENTS (Details 2) (USD $)	9 Months Ended	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Mar. 31, 2013	Mar. 31, 2012
INVESTMENTS	'	'	'
Proceeds from the sales and maturities of marketable securities	$90,470	$258,937	$323,028
Realized gains	16	39	47
Realized losses	'	$5	$11

INVESTMENTS_Details_3

INVESTMENTS (Details 3) (USD $)	Dec. 31, 2013
In Thousands, unless otherwise specified
Available-for-sale, Amortized Cost	'
Within 1 year	$107,374
After 1 year through 5 years	142,466
Total	249,840
Available-for-sale, Estimated Fair Value	'
Within 1 year	107,354
After 1 year through 5 years	142,400
Total	249,754
Held-to-maturity, Amortized Cost	'
Within 1 year	1,493
Total	1,493
Held-to-maturity, Estimated Fair Value	'
Within 1 year	1,493
Estimated Fair Value	$1,493

INVESTMENTS_Details_4

INVESTMENTS (Details 4) (USD $)	1 Months Ended	9 Months Ended	12 Months Ended
	Sep. 30, 2013	Dec. 31, 2013	Mar. 31, 2013	Mar. 31, 2012
INVESTMENTS	'	'	'	'
Investment in Acceleron Pharma, Inc., a collaborative partner	'	'	$8,700,000	'
Equity method investment	'	'	'	'
Additional investments	'	'	'	231,000
Civitas	'	'	'	'
Equity method investment	'	'	'	'
Carrying value of equity investment	'	2,000,000	800,000	'
Additional investments	1,200,000	'	'	'
Amount of promissory note converted into Series B preferred stock	1,200,000	'	'	'
Number of shares of Series B preferred stock issued on conversion of promissory note	844,415	'	'	'
Reduction in carrying value of investment of the entity, which represents the Company's share of investee's net losses	'	$1,200,000	$1,200,000	$800,000

FAIR_VALUE_Details

FAIR VALUE (Details) (Recurring basis, USD $)	Dec. 31, 2013	Mar. 31, 2013
In Thousands, unless otherwise specified
Level 1	'	'
Fair value	'	'
Assets, Total	$92,873	$76,226
Level 2	'	'
Fair value	'	'
Assets, Total	186,541	129,792
Liabilities, Total	-275	-541
Level 3	'	'
Fair value	'	'
Assets, Total	1,526	'
Total	'	'
Fair value	'	'
Assets, Total	280,940	206,018
Liabilities, Total	-275	-541
Interest rate swap contract | Level 2	'	'
Fair value	'	'
Interest rate swap contract	-275	-541
Interest rate swap contract | Total	'	'
Fair value	'	'
Interest rate swap contract	-275	-541
Cash equivalents | Level 1	'	'
Fair value	'	'
Available for sale securities	1,201	1,201
Cash equivalents | Total	'	'
Fair value	'	'
Available for sale securities	1,201	1,201
U.S. government and agency debt securities | Level 1	'	'
Fair value	'	'
Available for sale securities	63,213	75,025
U.S. government and agency debt securities | Level 2	'	'
Fair value	'	'
Available for sale securities	95,974	87,126
U.S. government and agency debt securities | Total	'	'
Fair value	'	'
Available for sale securities	159,187	162,151
Corporate debt securities | Level 2	'	'
Fair value	'	'
Available for sale securities	58,809	29,510
Corporate debt securities | Total	'	'
Fair value	'	'
Available for sale securities	58,809	29,510
International government agency debt securities | Level 2	'	'
Fair value	'	'
Available for sale securities	31,758	13,156
International government agency debt securities | Total	'	'
Fair value	'	'
Available for sale securities	31,758	13,156
Equity securities | Level 1	'	'
Fair value	'	'
Available for sale securities	28,459	'
Equity securities | Level 3	'	'
Fair value	'	'
Available for sale securities	1,526	'
Equity securities | Total	'	'
Fair value	'	'
Available for sale securities	$29,985	'

FAIR_VALUE_Details_2

FAIR VALUE (Details 2) (USD $)	9 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013
	item
Roll forward of the fair value of the Company's investments whose fair value was determined using Level 3 inputs	'
Number of investments transferred from level 1 to level 2	0
Number of investments transferred from level 2 to level 1	0
Conversion of investment from cost method to available-for-sale	$807
Total unrealized gains included in other comprehensive income (loss)	719
Balance at the end of the period	$1,526

FAIR_VALUE_Details_3

FAIR VALUE (Details 3) (USD $)	9 Months Ended
	Dec. 31, 2013
Assumptions used to determine the fair value of the warrants	'
Current warrant price (in dollars per share)	$39.60
Warrant strike price (in dollars per share)	$5.88
Expected term	'6 years 6 months
Risk-free rate (as a percent)	2.45%
Volatility (as a percent)	70.40%

FAIR_VALUE_Details_4

FAIR VALUE (Details 4) (USD $)	9 Months Ended
	Dec. 31, 2013	Mar. 31, 2013
Estimated fair value of the Term Loans	'	'
Carrying Value	$364,293,000	$369,008,000
Term Loan B-1	'	'
Estimated fair value of the Term Loans	'	'
Fair value of remaining financial instruments not recognized at fair value	300,000,000	'
Term loans maturity period	'7 years	'
Variable interest rate base	'LIBOR	'
Carrying Value	294,091,000	296,029,000
Estimated Fair Value	296,398,000	'
Term Loan B-2	'	'
Estimated fair value of the Term Loans	'	'
Fair value of remaining financial instruments not recognized at fair value	75,000,000	'
Term loans maturity period	'4 years	'
Variable interest rate base	'LIBOR	'
Carrying Value	70,202,000	72,979,000
Estimated Fair Value	$70,313,000	'
LIBOR | Term Loan B-1	'	'
Estimated fair value of the Term Loans	'	'
Interest rate added to base rate (as a percent)	2.75%	'
Interest rate, variable interest rate floor (as a percent)	0.75%	'
LIBOR | Term Loan B-2	'	'
Estimated fair value of the Term Loans	'	'
Interest rate added to base rate (as a percent)	2.75%	'
Interest rate, variable interest rate floor (as a percent)	0.00%	'

INVENTORY_Details

INVENTORY (Details) (USD $)	Dec. 31, 2013	Mar. 31, 2013
INVENTORY	'	'
Raw materials	$18,410,000	$13,506,000
Work in process	15,581,000	13,842,000
Finished goods	12,227,000	16,135,000
Total inventory	46,218,000	43,483,000
Finished goods inventory located at third-party warehouse and shipping service provider	$1,100,000	$600,000

PROPERTY_PLANT_AND_EQUIPMENT_D

PROPERTY, PLANT AND EQUIPMENT (Details) (USD $)	9 Months Ended	12 Months Ended
	Dec. 31, 2013	Mar. 31, 2013	Mar. 31, 2012
Property, plant and equipment	'	'	'
Subtotal	$428,136,000	$410,728,000	'
Less: accumulated depreciation	-153,646,000	-122,293,000	'
Total property, plant and equipment, net	274,490,000	288,435,000	'
Depreciation expense	32,300,000	31,900,000	22,500,000
Impairment of assets	'	3,346,000	45,800,000
Carrying value at the time of disposition	100,000	100,000	'
Proceeds from sale of property, plant and equipment	52,000	193,000	35,000
Land	'	'	'
Property, plant and equipment	'	'	'
Subtotal	8,440,000	8,357,000	'
Buildings and improvements	'	'	'
Property, plant and equipment	'	'	'
Subtotal	148,044,000	141,092,000	'
Furniture, fixtures and equipment	'	'	'
Property, plant and equipment	'	'	'
Subtotal	220,984,000	197,743,000	'
Furniture, fixtures and equipment | Maximum	'	'	'
Property, plant and equipment	'	'	'
Proceeds from sale of property, plant and equipment	100,000	100,000	'
Leasehold improvements	'	'	'
Property, plant and equipment	'	'	'
Subtotal	23,980,000	24,137,000	'
Construction in progress	'	'	'
Property, plant and equipment	'	'	'
Subtotal	$26,688,000	$39,399,000	'

GOODWILL_AND_INTANGIBLE_ASSETS2

GOODWILL AND INTANGIBLE ASSETS (Details) (USD $)	7 Months Ended			9 Months Ended		9 Months Ended		9 Months Ended
	Oct. 31, 2013	Dec. 31, 2013	Mar. 31, 2013	Dec. 31, 2013	Mar. 31, 2013	Dec. 31, 2013	Mar. 31, 2013	Dec. 31, 2013	Mar. 31, 2013
				Collaboration agreements	Collaboration agreements	NanoCrystal technology	NanoCrystal technology	OCR technologies	OCR technologies
Intangible assets	'	'	'	'	'	'	'	'	'
Gross Carrying Amount	'	$92,740,000	$92,740,000	'	'	'	'	'	'
Goodwill	'	92,740,000	92,740,000	'	'	'	'	'	'
Finite-lived intangible assets:	'	'	'	'	'	'	'	'	'
Weighted Amortizable Life	'	'	'	'12 years	'	'13 years	'	'12 years	'
Gross Carrying Amount	'	640,600,000	640,600,000	499,700,000	499,700,000	74,600,000	74,600,000	66,300,000	66,300,000
Accumulated Amortization	'	-103,035,000	-64,607,000	-80,655,000	-50,143,000	-8,506,000	-5,373,000	-13,874,000	-9,091,000
Net Carrying Amount	'	537,565,000	575,993,000	419,045,000	449,557,000	66,094,000	69,227,000	52,426,000	57,209,000
Impairment of goodwill	$0	'	'	'	'	'	'	'	'

GOODWILL_AND_INTANGIBLE_ASSETS3

GOODWILL AND INTANGIBLE ASSETS (Details 2) (USD $)	9 Months Ended	12 Months Ended
	Dec. 31, 2013	Mar. 31, 2013	Mar. 31, 2012
GOODWILL AND INTANGIBLE ASSETS	'	'	'
Amortization expense	$38,428,000	$41,852,000	$25,355,000
Expected amortization of intangible assets	'	'	'
2014	60,000,000	'	'
2015	65,000,000	'	'
2016	70,000,000	'	'
2017	70,000,000	'	'
2018	$70,000,000	'	'

ACCOUNTS_PAYABLE_AND_ACCRUED_E2

ACCOUNTS PAYABLE AND ACCRUED EXPENSES (Details) (USD $)	3 Months Ended
	Jun. 30, 2013	Dec. 31, 2013	Mar. 31, 2013
ACCOUNTS PAYABLE AND ACCRUED EXPENSES	'	'	'
Accounts payable	'	$19,493,000	$18,282,000
Accrued compensation	'	28,101,000	30,432,000
Accrued restructuring	'	7,296,000	602,000
Accrued other	'	36,283,000	27,594,000
Total accounts payable and accrued expenses	'	91,173,000	76,910,000
Out-of-period adjustment recorded to correct an over-accrued liability from the prior year	$1,000,000	'	'

RESTRUCTURING_Details

RESTRUCTURING (Details) (USD $)	9 Months Ended	12 Months Ended
	Dec. 31, 2013	Mar. 31, 2013
Restructuring activity	'	'
Cash paid for restructuring costs	$2,300,000	'
Foreign currency adjustment	600,000	'
Restructuring activity	'	'
Balance at beginning of the period	602,000	'
Payments	'	12,300,000
Balance at end of the period	7,296,000	602,000
Restructuring accrual	'	'
Restructuring accrual	7,296,000	602,000
Accounts payable and accrued expenses	'	'
Restructuring activity	'	'
Balance at end of the period	6,800,000	0
Restructuring accrual	'	'
Restructuring accrual	6,800,000	0
Other long-term liabilities	'	'
Restructuring activity	'	'
Balance at end of the period	3,800,000	12,300,000
Restructuring accrual	'	'
Restructuring accrual	3,800,000	12,300,000
Athlone, Ireland manufacturing facility | Maximum	'	'
Restructuring activity	'	'
Expected number of employees to be eliminated	130	'
Severance and outplacement services	'	'
Restructuring activity	'	'
Balance at beginning of the period	12,300,000	'
Payments	-2,279,000	'
Adjustments	557,000	'
Balance at end of the period	10,578,000	'
Restructuring accrual	'	'
Restructuring accrual	$10,578,000	'

LONGTERM_DEBT_Details

LONG-TERM DEBT (Details) (USD $)	0 Months Ended	9 Months Ended
	Dec. 31, 2012	Dec. 31, 2013	Mar. 31, 2013
Long-term debt	'	'	'
Total	'	$364,293,000	$369,008,000
Less: current portion	'	-6,750,000	-6,750,000
Long-term debt	'	357,543,000	362,258,000
Original issue discount	'	2,300,000	'
2013 Term Loans	'	'	'
Long-term debt	'	'	'
Total	'	366,563,000	'
Percentage of repricing premium on outstanding credit agreement balance, if prepayment is made in connection with an amendment to the agreement resulting in a refinancing transaction	'	1.00%	'
New Term Loan Facility	'	'	'
Long-term debt	'	'	'
Incremental capacity	'	140,000,000	'
Percentage of present value of future cash flows remaining under Existing Senior Credit Facilities	'	10.00%	'
Term Loan B-1, due September 25, 2019	'	'	'
Long-term debt	'	'	'
Total	'	294,091,000	296,029,000
Aggregate principal amount	'	300,000,000	'
Variable interest rate base	'	'LIBOR	'
Original issue discount	'	3,000,000	'
Term Loan quarterly amortization price as percentage of original principal amount	'	0.25%	'
Required quarterly principal payments	800,000	'	'
Term Loan B-1, due September 25, 2019 | LIBOR	'	'	'
Long-term debt	'	'	'
Interest rate added to base rate (as a percent)	'	2.75%	'
Interest rate, variable interest rate floor	'	0.75%	'
Term Loan B-2, due September 25, 2016	'	'	'
Long-term debt	'	'	'
Total	'	70,202,000	72,979,000
Aggregate principal amount	'	75,000,000	'
Variable interest rate base	'	'LIBOR	'
Original issue discount	'	400,000	'
Term Loan quarterly amortization price as percentage of original principal amount	'	1.25%	'
Required quarterly principal payments	$900,000	'	'
Term Loan B-2, due September 25, 2016 | LIBOR	'	'	'
Long-term debt	'	'	'
Interest rate added to base rate (as a percent)	'	2.75%	'
Interest rate, variable interest rate floor	'	0.00%	'

LONGTERM_DEBT_Details_2

LONG-TERM DEBT (Details 2) (USD $)	Dec. 31, 2013	Mar. 31, 2013
In Thousands, unless otherwise specified
Scheduled maturities of Credit Agreement	'	'
Total	$364,293	$369,008
Term Loans	'	'
Scheduled maturities of Credit Agreement	'	'
2014	6,750	'
2015	6,750	'
2016	65,813	'
2017	3,000	'
2018	3,000	'
Thereafter	281,250	'
Total	$366,563	'

LONGTERM_DEBT_Details_3

LONG-TERM DEBT (Details 3) (USD $)	9 Months Ended	12 Months Ended
	Dec. 31, 2013	Mar. 31, 2013	Mar. 31, 2012
Extinguished debt:	'	'	'
Unamortized deferred financing costs	'	$6,166,000	'
Unamortized original issue discount	'	4,094,000	'
Modified debt:	'	'	'
Debt financing costs	'	2,772,000	'
Original issue discount	'	105,000	'
Prepayment penalty	'	6,533,000	'
Total	'	19,670,000	'
Unamortized deferred financing costs at period end	2,700,000	'	'
Amortization of offering costs and discount	800,000	5,800,000	3,500,000
Unamortized original issue discount	2,300,000	'	'
September 2012 Refinancing	'	'	'
Extinguished debt:	'	'	'
Unamortized deferred financing costs	'	4,600,000	'
Unamortized original issue discount	'	2,657,000	'
Modified debt:	'	'	'
Debt financing costs	'	1,967,000	'
Original issue discount	'	105,000	'
Prepayment penalty	'	2,800,000	'
Total	'	12,129,000	'
February 2013 Repricing	'	'	'
Extinguished debt:	'	'	'
Unamortized deferred financing costs	'	1,566,000	'
Unamortized original issue discount	'	1,437,000	'
Modified debt:	'	'	'
Debt financing costs	'	805,000	'
Prepayment penalty	'	3,733,000	'
Total	'	$7,541,000	'

DERIVATIVE_INSTRUMENTS_Details

DERIVATIVE INSTRUMENTS (Details) (USD $)	12 Months Ended		1 Months Ended	9 Months Ended		1 Months Ended		12 Months Ended			9 Months Ended
	Mar. 31, 2013	Mar. 31, 2013	Dec. 31, 2012	Dec. 31, 2013	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Mar. 31, 2013	Dec. 31, 2013	Mar. 31, 2012	Dec. 31, 2013
		Reclassification	Interest rate caps	Interest rate caps	Interest rate caps	Interest rate caps	Interest rate caps	Interest rate swap	Interest rate swap	Interest rate swap	Interest rate swap
			Not designated as hedging instrument	Not designated as hedging instrument	Not designated as hedging instrument	Not designated as hedging instrument	Designated as cash flow hedge	Cash flow hedge	Not designated as hedging instrument	Not designated as hedging instrument	Designated as cash flow hedge
						Maximum		Reclassification
Derivative instruments	'	'	'	'	'	'	'	'	'	'	'
Cost of interest rate cap	'	'	$100,000	'	'	$100,000	'	'	'	'	'
Variable interest rate base	'	'	'	'three-Month LIBOR	'	'	'	'	'	'	'three-Month LIBOR
Notional value	'	'	'	160,000,000	65,000,000	'	65,000,000	'	'	'	'
Loss on derivative instrument due to decreased in value of the contract	'	'	'	300,000	'	'	'	'	'	'	'
Unrealized losses	'	600,000	'	'	'	'	'	'	'	'	'
Reclassification of unrealized losses to realized losses	594,000	'	'	'	'	'	'	600,000	'	'	'
Fair value of derivative instrument	'	'	'	'	'	'	'	'	($275,000)	($541,000)	'

EARNINGS_LOSS_PER_SHARE_Detail

EARNINGS (LOSS) PER SHARE (Details) (USD $)	9 Months Ended		12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Mar. 31, 2013	Mar. 31, 2012
Numerator:	'	'	'	'
Net income (loss)	$17,649	$21,984	$24,983	($113,678)
Denominator:	'	'	'	'
Weighted average number of ordinary shares outstanding	135,960	131,202	131,713	114,702
Effect of dilutive securities:	'	'	'	'
Dilutive ordinary share equivalents (in shares)	9,001	'	5,387	'
Shares used in calculating diluted earnings (loss) per share	144,961	136,216	137,100	114,702
Stock options	'	'	'	'
Effect of dilutive securities:	'	'	'	'
Dilutive ordinary share equivalents (in shares)	7,653	'	4,025	'
Restricted stock units	'	'	'	'
Effect of dilutive securities:	'	'	'	'
Dilutive ordinary share equivalents (in shares)	1,348	'	1,362	'

EARNINGS_LOSS_PER_SHARE_Detail1

EARNINGS (LOSS) PER SHARE (Details 2)	9 Months Ended	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Mar. 31, 2013	Mar. 31, 2011
Denominator:	'	'	'
Anti-dilutive potential common equivalent shares excluded from calculation of net income (loss) per share	1,404	4,497	9,504
Stock options	'	'	'
Denominator:	'	'	'
Anti-dilutive potential common equivalent shares excluded from calculation of net income (loss) per share	1,404	4,497	8,299
Restricted stock units	'	'	'
Denominator:	'	'	'
Anti-dilutive potential common equivalent shares excluded from calculation of net income (loss) per share	'	'	1,205

SHAREHOLDERS_EQUITY_Details

SHAREHOLDERS' EQUITY (Details) (USD $)	0 Months Ended	9 Months Ended
In Millions, unless otherwise specified	Sep. 16, 2011	Dec. 31, 2013
SHAREHOLDERS' EQUITY	'	'
Value of shares authorized under repurchase program	$215	'
Value of shares available for repurchase pursuant to repurchase program	'	$101

SHAREBASED_COMPENSATION_Detail

SHARE-BASED COMPENSATION (Details) (USD $)	9 Months Ended	12 Months Ended
	Dec. 31, 2013	Mar. 31, 2013	Mar. 31, 2012
Share-based Compensation Expense	'	'	'
Total share-based compensation expense	$33,409,000	$34,716,000	$28,826,000
Share based compensation cost capitalized	400,000	600,000	400,000
Cost of goods manufactured and sold	'	'	'
Share-based Compensation Expense	'	'	'
Total share-based compensation expense	3,308,000	4,375,000	2,962,000
Research and development	'	'	'
Share-based Compensation Expense	'	'	'
Total share-based compensation expense	7,799,000	9,078,000	8,784,000
Selling, general and administrative	'	'	'
Share-based Compensation Expense	'	'	'
Total share-based compensation expense	$22,302,000	$21,263,000	$17,080,000

SHAREBASED_COMPENSATION_Detail1

SHARE-BASED COMPENSATION (Details 2)	9 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013
	item
Share-Based Compensation	'
Number of share-based compensation plans under which awards are currently made	2
Number of share-based compensation plans under which no further awards will be made	5
Shares of common stock authorized for issuance	10.4
2011 Plan	'
Share-Based Compensation	'
Ratio of awards other than stock options counted against the total number of shares available for issuance	1.8
2008 Plan	'
Share-Based Compensation	'
Ratio of awards other than stock options counted against the total number of shares available for issuance	2

SHAREBASED_COMPENSATION_Detail2

SHARE-BASED COMPENSATION (Details 3) (Stock options, USD $)	9 Months Ended	12 Months Ended
In Millions, except Share data, unless otherwise specified	Dec. 31, 2013	Mar. 31, 2013	Mar. 31, 2012
Stock options	'	'	'
Number of Shares	'	'	'
Outstanding at the beginning of the period (in shares)	16,451,104	'	'
Granted (in shares)	2,047,250	'	'
Exercised (in shares)	-3,497,443	'	'
Forfeited (in shares)	-312,750	'	'
Expired (in shares)	-1	'	'
Outstanding at the end of the period (in shares)	14,688,160	16,451,104	'
Exercisable at the end of the period (in shares)	9,372,735	'	'
Weighted Average Exercise Price	'	'	'
Outstanding at the beginning of the period (in dollars per share)	$14.57	'	'
Granted (in dollars per share)	$33.52	'	'
Exercised (in dollars per share)	$14.26	'	'
Forfeited (in dollars per share)	$19.29	'	'
Expired (in dollars per share)	$14.62	'	'
Outstanding at the end of the period (in dollars per share)	$17.18	$14.57	'
Exercisable at the end of the period (in dollars per share)	$14.54	'	'
Additional disclosures	'	'	'
Weighted average grant-date fair value of stock options granted (in dollars per share)	$16.27	$8.11	$8
Aggregate intrinsic value of stock options exercised	$65.60	$28.10	$11.10
Stock options expected to vest	'	'	'
Stock options expected to vest (in shares)	5,200,000	'	'
Weighted average exercise price (in dollars per share)	$21.73	'	'
Weighted average contractual remaining life	'8 years 3 months 18 days	'	'
Aggregate intrinsic value	98.3	'	'
Additional disclosures	'	'	'
Aggregate intrinsic value of stock options exercisable	244.8	'	'
Weighted average remaining contractual term of stock options exercisable	'4 years 10 months 24 days	'	'
Unrecognized compensation cost	30.7	'	'
Weighted average period for unrecognized compensation cost expected to be recognized	'2 years	'	'
Cash received from option exercises	$49.10	$34.40	$20.90

SHAREBASED_COMPENSATION_Detail3

SHARE-BASED COMPENSATION (Details 4) (Time-vested RSUs, USD $)	9 Months Ended	12 Months Ended
In Millions, except Share data, unless otherwise specified	Dec. 31, 2013	Mar. 31, 2013	Mar. 31, 2012
Time-vested RSUs	'	'	'
Number of Shares	'	'	'
Unvested at the beginning of the period (in shares)	2,226,771	'	'
Granted (in shares)	770,150	'	'
Vested (in shares)	-920,021	'	'
Forfeited (in shares)	-89,013	'	'
Unvested at the end of the period (in shares)	1,987,887	2,226,771	'
Weighted Average Grant Date Fair Value	'	'	'
Unvested at the beginning of the period (in dollars per share)	$15.14	'	'
Granted (in dollars per share)	$33.72	$16.55	$17.91
Vested (in dollars per share)	$13.56	'	'
Forfeited (in dollars per share)	$20.37	'	'
Unvested at the end of the period (in dollars per share)	$22.83	$15.14	'
Additional disclosures	'	'	'
Fair value of RSU's vested	$12.50	$9.90	$6.10
Unrecognized compensation cost	$24.70	'	'
Weighted average period for unrecognized compensation cost expected to be recognized	'2 years	'	'

COLLABORATIVE_ARRANGEMENTS_Det

COLLABORATIVE ARRANGEMENTS (Details) (USD $)

9 Months Ended

12 Months Ended

9 Months Ended

12 Months Ended

9 Months Ended

12 Months Ended

9 Months Ended

12 Months Ended

9 Months Ended

12 Months Ended

9 Months Ended

12 Months Ended

9 Months Ended

Dec. 31, 2013

Mar. 31, 2013

Mar. 31, 2012

Dec. 31, 2013

Mar. 31, 2013

Mar. 31, 2012

Jul. 31, 2011

Feb. 29, 2012

Dec. 31, 2013

Mar. 31, 2013

Mar. 31, 2012

Dec. 31, 2013

Mar. 31, 2013

Mar. 31, 2012

Dec. 31, 2013

Dec. 31, 2013

Mar. 31, 2013

Mar. 31, 2012

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Mar. 31, 2013

Mar. 31, 2012

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

U.S

U.S

U.S

RISPERDAL CONSTA

RISPERDAL CONSTA

RISPERDAL CONSTA

BYDUREON

BYDUREON

Acorda

Acorda

Acorda

AstraZeneca

AstraZeneca

AstraZeneca

License agreement

License agreement

License agreement

License agreement

License agreement

License agreement

License agreement

License agreement

License agreement

License agreement

License agreement

License agreement

License agreement

Manufacturing and supply agreement

Manufacturing and supply agreement

Manufacturing and supply agreement

Manufacturing and supply agreement

Manufacturing and supply agreement

Manufacturing and supply agreement

Manufacturing and supply agreement

Development and license agreement

EU

U.S

Janssen

Janssen

Janssen

Janssen

Janssen

Janssen

Janssen

Janssen

Janssen

Janssen

Janssen

Acorda

Acorda

Janssen

Janssen

Janssen

Janssen

Janssen

Acorda

Acorda

AstraZeneca

RISPERDAL CONSTA

INVEGA SUSTENNA/XEPLION

INVEGA SUSTENNA/XEPLION

INVEGA SUSTENNA/XEPLION

INVEGA SUSTENNA/XEPLION

INVEGA SUSTENNA/XEPLION

INVEGA SUSTENNA/XEPLION

INVEGA SUSTENNA/XEPLION

INVEGA SUSTENNA/XEPLION

INVEGA SUSTENNA/XEPLION

INVEGA SUSTENNA/XEPLION

AMPYRA/ FAMPYRA

RISPERDAL CONSTA

RISPERDAL CONSTA

RISPERDAL CONSTA

RISPERDAL CONSTA

RISPERDAL CONSTA

AMPYRA/ FAMPYRA

AMPYRA/ FAMPYRA

BYDUREON

Net sales of below $250.0 million

Net sales between $250.0 million and 500.0 million

Net sales greater than $500.0 million

Minimum

Minimum

Maximum

Maximum

Minimum

Maximum

Maximum

item

Net sales between $250.0 million and 500.0 million

Net sales between $250.0 million and 500.0 million

Collaborative Arrangements and Non-collaborative Arrangement Transactions

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Royalty rate (as a percent)

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2.50%

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5.00%

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9.00%

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10.00%

7.50%

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8.00%

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Patent royalty rate (as a percent)

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1.50%

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Know-how royalty rate (as a percent)

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3.50%

5.50%

7.50%

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Aggregate worldwide net sales

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$250,000,000

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$500,000,000

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$250,000,000

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$500,000,000

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Milestone payment to be received upon the first commercial sale

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7,000,000

7,000,000

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Notice period required to be given before termination of agreement

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'30 days

'3 months

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'90 days

'6 months

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'12 months

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'180 days

Period after the date of the first commercial sale of the product for license expiration

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'15 years

'15 years

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'10 years

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'10 years

Period for resolving default or breach after the receipt of notice for termination of agreement

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'90 days

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'60 days

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'60 days

Royalty rate upon termination of manufacturing and supply agreement (as a percent)

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2.50%

5.00%

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Revenue recognized

269,005,000

380,565,000

212,859,000

82,500,000

98,600,000

129,800,000

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51,600,000

65,000,000

25,800,000

20,000,000

23,800,000

18,800,000

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82,900,000

63,500,000

18,000,000

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24,700,000

35,000,000

38,500,000

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Percentage of total annual requirement of product that can be obtained from second source manufacturer

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25.00%

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Royalty as a percentage of net sales from the first 40 million units

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8.00%

Royalty as a percentage of net sales beyond the first 40 million units

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5.50%

Threshold for number of units sold used to determine royalty rate

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40,000,000

Milestone payment entitled to be received upon the initiation of phase 3 clinical trial

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1,000,000

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Milestone payment entitled to be received upon the acceptance of NDA by the FDA

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1,000,000

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Milestone payment entitled to be received upon the approval of NDA by the FDA

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1,500,000

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Milestone payment entitled to be received upon the first commercial sale

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$1,500,000

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INCOME_TAXES_Details

INCOME TAXES (Details) (USD $)	9 Months Ended		12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Mar. 31, 2013	Mar. 31, 2012
Deferred income tax (benefit) provision:	'	'	'	'
Deferred income tax (benefit) provision	($15,393,000)	'	($2,113,000)	($14,556,000)
Provison for income tax provided on undistributed earnings of foreign subsidiaries	0	'	'	'
Cumulative unremitted earnings of overseas subsidiaries	53,700,000	'	'	'
Total tax (benefit) provision	-12,252,000	5,591,000	10,458,000	-714,000
Income tax benefit due to utilization of NOL carryforwards	11,400,000	'	8,900,000	'
Provision on taxable transfer of the BYDEREON intellectual property	'	'	'	13,100,000
Benefit recorded to additional paid-in capital	'	'	'	4,300,000
Ireland	'	'	'	'
Deferred income tax (benefit) provision:	'	'	'	'
Deferred income tax (benefit) provision	-3,426,000	'	-1,961,000	-4,551,000
U.S. Federal	'	'	'	'
Current income tax provision (benefit):	'	'	'	'
Current income tax provision (benefit)	9,224,000	'	8,152,000	7,321,000
Deferred income tax (benefit) provision:	'	'	'	'
Deferred income tax (benefit) provision	-18,317,000	'	'	-10,024,000
U.S. state	'	'	'	'
Current income tax provision (benefit):	'	'	'	'
Current income tax provision (benefit)	2,119,000	'	2,588,000	6,649,000
Deferred income tax (benefit) provision:	'	'	'	'
Deferred income tax (benefit) provision	-1,941,000	'	-79,000	-137,000
Rest of world	'	'	'	'
Current income tax provision (benefit):	'	'	'	'
Current income tax provision (benefit)	$89,000	'	$1,758,000	$28,000

INCOME_TAXES_Details_2

INCOME TAXES (Details 2) (USD $)	9 Months Ended		12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Mar. 31, 2013	Mar. 31, 2012
Distribution of income (loss) before provision for income taxes	'	'	'	'
Income (loss) before the provision for income taxes	$5,397	$27,575	$35,441	($114,392)
Ireland	'	'	'	'
Distribution of income (loss) before provision for income taxes	'	'	'	'
Income (loss) before the provision for income taxes	-63,975	'	-14,722	-36,711
UNITED STATES	'	'	'	'
Distribution of income (loss) before provision for income taxes	'	'	'	'
Income (loss) before the provision for income taxes	49,338	'	23,503	-84,858
Rest of world	'	'	'	'
Distribution of income (loss) before provision for income taxes	'	'	'	'
Income (loss) before the provision for income taxes	$20,034	'	$26,660	$7,177

INCOME_TAXES_Details_3

INCOME TAXES (Details 3) (USD $)	Dec. 31, 2013	Mar. 31, 2013	Dec. 31, 2013	Mar. 31, 2013	Dec. 31, 2013	Dec. 31, 2013	Dec. 31, 2013
			Ireland	Ireland	Federal	State	Federal, State, and Local
Income taxes	'	'	'	'	'	'	'
Recognized benefit related to reversal of valuation allowance	'	'	'	'	'	'	$26,500,000
Less: valuation allowance	-69,659,000	-86,714,000	-58,900,000	'	-9,100,000	'	-10,700,000
Operating loss carryforwards	'	'	494,600,000	'	77,100,000	9,800,000	'
Amount of operating loss and tax credit carryforwards subject to annual limitation.	'	'	'	'	127,000,000	'	'
NOL carryforwards	'	'	68,459,000	55,842,000	'	'	'
Deferred tax assets :	'	'	'	'	'	'	'
Tax benefit from the exercise of stock options	9,122,000	8,437,000	'	'	'	'	'
Share-based compensation	24,353,000	23,468,000	'	'	'	'	'
Tax credit carryforwards	6,247,000	10,543,000	'	'	'	'	'
Property, plant and equipment	1,912,000	653,000	'	'	'	'	'
Bonus accrual	4,585,000	7,034,000	'	'	'	'	'
Other	10,538,000	11,605,000	'	'	'	'	'
Less: valuation allowance	-69,659,000	-86,714,000	-58,900,000	'	-9,100,000	'	-10,700,000
Total deferred tax assets	55,557,000	30,868,000	'	'	'	'	'
Deferred tax liabilities :	'	'	'	'	'	'	'
Intangible assets	-38,238,000	-40,968,000	'	'	'	'	'
Property, plant and equipment	-21,571,000	-19,607,000	'	'	'	'	'
Unrealized gains on investment	-7,719,000	'	'	'	'	'	'
Other	-4,421,000	-2,072,000	'	'	'	'	'
Total deferred tax liabilities	-71,949,000	-62,647,000	'	'	'	'	'
Net deferred tax liabilities	-16,392,000	-31,779,000	'	'	'	'	'
Schedule of current and non-current deferred tax assets (liabilities)	'	'	'	'	'	'	'
Current deferred tax assets	12,777,000	5,824,000	'	'	'	'	'
Non-current deferred tax liabilities	-29,169,000	-37,603,000	'	'	'	'	'
Net deferred tax liabilities	($16,392,000)	($31,779,000)	'	'	'	'	'

INCOME_TAXES_Details_4

INCOME TAXES (Details 4) (USD $)	Dec. 31, 2013	Mar. 31, 2013
Income taxes	'	'
Additional tax benefits from stock option exercises that have not been recognized	$9,122,000	$8,437,000
ASC 718	'	'
Income taxes	'	'
Additional tax benefits from stock option exercises and the vesting of restricted stock units that have not been recognized	41,100,000	'
Total tax benefit from the exercise of stock options and the vesting of restricted stock units including unrecognized benefits	50,200,000	'
Federal research and development credits	22,300,000	'
Alternative minimum tax	7,500,000	'
State tax credits	$600,000	'

INCOME_TAXES_Details_5

INCOME TAXES (Details 5) (USD $)	9 Months Ended	12 Months Ended
	Dec. 31, 2013	Mar. 31, 2013	Mar. 31, 2012
Reconciliation of the company's federal statutory tax rate to its effective rate	'	'	'
Statutory tax rate (as a percent)	12.50%	12.50%	12.50%
U.S. state income taxes, net of U.S. federal benefit (as a percent)	40.80%	4.70%	-6.80%
R&D credit (as a percent)	-29.60%	-20.50%	-8.40%
Share-based compensation (as a percent)	13.60%	3.30%	-0.70%
Non-refundable withholding tax (as a percent)	0.40%	4.70%	'
Permanent items (as a percent)	-83.60%	-8.20%	'
State tax law change	12.70%	'	'
Change in valuation allowance (as a percent)	-321.40%	-7.50%	55.70%
Rate differential (as a percent)	127.60%	40.50%	-51.70%
Effective tax rate (as a percent)	-227.00%	29.50%	0.60%
Reconciliation of the beginning and ending amount of unrecognized tax benefits	'	'	'
Balance at the beginning of the period	$7,258,000	$6,606,000	$4,933,000
Additions based on tax positions related to prior periods	881,000	1,065,000	1,741,000
Decreases due to lapse of statute of limitations	'	'	-68,000
Decreases due to settlements with tax authorities	'	-413,000	'
Additions based on tax positions related to the current period	244,000	'	'
Decreases due to lapse of statute of limitations and settlement of prior period uncertain tax positions	-7,258,000	'	'
Balance at the end of the period	1,125,000	7,258,000	6,606,000
Unrecognized tax benefit that would affect effective tax rate	$1,100,000	'	'
Minimum	'	'	'
Reconciliation of the beginning and ending amount of unrecognized tax benefits	'	'	'
Period after loss carryforwards utilized that tax returns remain open to examination	'3 years	'	'
Maximum	'	'	'
Reconciliation of the beginning and ending amount of unrecognized tax benefits	'	'	'
Period after loss carryforwards utilized that tax returns remain open to examination	'4 years	'	'

TRANSITION_PERIOD_COMPARATIVE_2

TRANSITION PERIOD COMPARATIVE DATA (Details) (USD $)	9 Months Ended		12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Mar. 31, 2013	Mar. 31, 2012
Statement of Operations Data:	'	'	'	'
Revenues	$432,911	$412,126	$575,548	$389,977
Operating expenses	417,417	349,297	493,735	478,258
OPERATING INCOME (LOSS)	15,494	62,829	81,813	-88,281
Other expense (net)	-10,097	-35,254	-46,372	-26,111
INCOME (LOSS) BEFORE INCOME TAXES	5,397	27,575	35,441	-114,392
Income tax (benefit) provision	-12,252	5,591	10,458	-714
NET INCOME (LOSS)	17,649	21,984	24,983	-113,678
Earnings per ordinary share - basic	$0.13	$0.17	$0.19	($0.99)
Earnings per ordinary share - diluted	$0.12	$0.16	$0.18	($0.99)
Weighted average ordinary shares outstanding - basic	135,960	131,202	131,713	114,702
Weighted average ordinary shares outstanding - diluted	144,961	136,216	137,100	114,702
Statement of Cash Flows Data:	'	'	'	'
Cash flows provided by operations	92,221	71,247	126,551	-2,482
Cash flows (used in) provided by investing activities	-65,366	43,680	-68,148	-417,159
Cash flows provided by (used in) financing activities	43,746	-62,636	-45,043	464,848
NET INCREASE IN CASH AND CASH EQUIVALENTS	$70,601	$52,291	$13,360	$45,207

COMMITMENTS_AND_CONTINGENCIES_1

COMMITMENTS AND CONTINGENCIES (Details) (USD $)	9 Months Ended	12 Months Ended
	Dec. 31, 2013	Mar. 31, 2013	Mar. 31, 2012
Future minimum rental commitments under non-cancelable operating leases	'	'	'
2014	$4,816,000	'	'
2015	4,950,000	'	'
2016	4,281,000	'	'
2017	4,447,000	'	'
2018	4,513,000	'	'
Thereafter	7,409,000	'	'
Total future minimum lease payments before estimated sublease income	30,416,000	'	'
Less: estimated sublease income	-1,444,000	'	'
Total future minimum lease payments	28,972,000	'	'
Rent expense related to operating leases	'	'	'
Rent expense	3,700,000	5,000,000	4,200,000
Sublease income	700,000	2,600,000	9,200,000
Purchase commitments	'	'	'
Open purchase order commitments	$101,800,000	'	'
Maximum	'	'	'
Lease Commitments	'	'	'
Provisions for extension of lease term	'10 years	'	'

SUBSEQUENT_EVENTS_Details

SUBSEQUENT EVENTS (Details) (USD $)	Dec. 31, 2013	Mar. 31, 2013	Jan. 31, 2014
In Millions, except Share data, unless otherwise specified			Subsequent event
Subsequent events	'	'	'
Ordinary shares sold	'	'	5,917,160
Ordinary shares, par value (in dollars per share)	$0.01	$0.01	$0.01
Share price (in dollar per share)	'	'	$42.25
Total gross proceeds before deducting expenses associated with the offering	'	'	$250