Forest Laboratories (FRX) Inactive 10-K30 May 142014 FY Annual reportFinancial data

Company Profile

Document_and_Entity_Informatio

Document and Entity Information (USD $)	12 Months Ended
Document and Entity Information (USD $)	Mar. 31, 2014	29-May-14	Sep. 30, 2013
Document and Entity Information [Abstract]	'	'	'
Entity Registrant Name	'FOREST LABORATORIES INC	'	'
Entity Central Index Key	'0000038074	'	'
Current Fiscal Year End Date	'--03-31	'	'
Entity Well-known Seasoned Issuer	'Yes	'	'
Entity Voluntary Filers	'No	'	'
Entity Current Reporting Status	'Yes	'	'
Entity Filer Category	'Large Accelerated Filer	'	'
Entity Public Float	'	'	$11,403,997,603
Entity Common Stock, Shares Outstanding	'	272,594,304	'
Document Fiscal Year Focus	'2014	'	'
Document Fiscal Period Focus	'FY	'	'
Document Type	'10-K	'	'
Amendment Flag	'false	'	'
Document Period End Date	31-Mar-14	'	'

CONSOLIDATED_BALANCE_SHEETS

CONSOLIDATED BALANCE SHEETS (USD $)	Mar. 31, 2014	Mar. 31, 2013
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Current assets:	'	'
Cash (including cash equivalent investments of $1,198,750 at March 31, 2014 and $867,112 at March 31, 2013)	$1,780,036	$935,675
Marketable securities	373,014	739,198
Accounts receivable, less allowance for doubtful accounts of $2,031 at March 31, 2014 and $2,003 at March 31, 2013	576,854	478,032
Inventories, net	612,664	393,901
Deferred income taxes	313,237	266,455
Prepaid and other current assets	467,907	134,525
Total current assets	4,123,712	2,947,786
Non-current assets:	'	'
Marketable securities and investments	1,170,141	1,349,424
Property, plant and equipment, net	371,815	376,960
Goodwill	1,048,508	713,091
License agreements, product rights and other intangibles, net	5,160,939	2,127,639
Other assets	142,416	114,682
Total assets	12,017,531	7,629,582
Current liabilities:	'	'
Accounts payable	221,025	157,349
Accrued expenses and other liabilities	1,289,644	840,342
Total current liabilities	1,510,669	997,691
Long-term liabilities:	'	'
Long-term debt	3,000,000	0
Income tax liabilities	531,128	567,311
Deferred tax liabilities	739,869	283,245
Other long-term liabilities	70,301	36,080
Total liabilities	5,851,967	1,884,327
Contingencies (Note 13)	'	'
Stockholders' equity:	'	'
Preferred stock, $1.00 par; shares authorized 1,000; no shares issued or outstanding	'	'
Common stock $.10 par; shares authorized 1,000,000; issued 436,368 shares in 2014 and 430,385 shares in 2013	43,637	43,039
Additional paid-in capital	2,061,070	1,799,071
Retained earnings	9,220,654	9,055,344
Accumulated other comprehensive income (loss)	12,109	10,116
Treasury stock, at cost (164,037 shares in 2014 and 163,886 shares in 2013)	-5,171,906	-5,162,315
Total stockholders' equity	6,165,564	5,745,255
Total liabilities and stockholders' equity	$12,017,531	$7,629,582

CONSOLIDATED_BALANCE_SHEETS_Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) (USD $)	Mar. 31, 2014	Mar. 31, 2013
In Thousands, except Per Share data, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Current assets:	'	'
Cash equivalent investments	$1,198,750	$867,112
Accounts receivable, allowance for doubtful accounts	$2,031	$2,003
Stockholders' equity:	'	'
Preferred stock, par value (in dollars per share)	$1	$1
Preferred stock, shares authorized (in shares)	1,000	1,000
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Common stock, par value (in dollars per share)	$0.10	$0.10
Common stock, shares authorized (in shares)	1,000,000	1,000,000
Common stock, shares issued (in shares)	436,368	430,385
Treasury stock, shares (in shares)	164,037	163,886

CONSOLIDATED_STATEMENTS_OF_OPE

CONSOLIDATED STATEMENTS OF OPERATIONS (USD $)	12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2012
Net revenue	'	'	'
Net sales	$3,503,346	$2,904,936	$4,392,548
Contract and other revenue	143,553	189,066	155,214
Total revenue	3,646,899	3,094,002	4,547,762
Cost of goods sold	760,642	649,083	998,087
Gross profit	2,886,257	2,444,919	3,549,675
Operating expenses	'	'	'
Selling, general and administrative	1,986,229	1,558,306	1,553,337
Research and development	788,276	963,594	796,932
Total operating expenses	2,774,505	2,521,900	2,350,269
Operating income (loss)	111,752	-76,981	1,199,406
Interest and other income (expense), net	-30,184	32,123	38,282
Income (loss) before income taxes	81,568	-44,858	1,237,688
Income tax expense (benefit)	-83,742	-12,755	258,630
Net income (loss)	$165,310	($32,103)	$979,058
Net income (loss) per common share:	'	'	'
Basic (in dollars per share)	$0.61	($0.12)	$3.58
Diluted (in dollars per share)	$0.61	($0.12)	$3.57
Weighted average number of common shares outstanding:	'	'	'
Basic (in shares)	269,129	266,807	273,561
Diluted (in shares)	272,947	266,807	274,016

CONSOLIDATED_STATEMENTS_OF_COM

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2012
CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) [Abstract]	'	'	'
Net income (loss)	$165,310	($32,103)	$979,058
Other comprehensive income (loss):	'	'	'
Foreign currency translation gain (loss)	11,055	-7,720	-14,747
Pension liability adjustment, net of tax	6,601	2,582	1,556
Unrealized gains (losses) on securities:	'	'	'
Unrealized holding gain (loss) arising during the period, net of tax	-15,663	18,188	2,261
Other comprehensive income (loss)	1,993	13,050	-10,930
Comprehensive income (loss)	$167,303	($19,053)	$968,128

CONSOLIDATED_STATEMENTS_OF_STO

CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (USD $)	Common Stock [Member]	Additional paid-in capital [Member]	Retained earnings [Member]	Accumulated other comprehensive income (loss) [Member]	Treasury stock [Member]	Total
In Thousands	Common Stock [Member]	Additional paid-in capital [Member]	Retained earnings [Member]	Accumulated other comprehensive income (loss) [Member]	Treasury stock [Member]	Total
Balance at Mar. 31, 2011	$42,498	$1,631,887	$8,108,389	$7,996	$4,291,890	'
Balance (in shares) at Mar. 31, 2011	424,982	'	'	'	138,863	'
Shares issued upon exercise of stock options and vesting of restricted stock	377	9,512	'	'	'	'
Shares issued upon exercise of stock options and vesting of restricted stock (in shares)	3,764	'	'	'	'	'
Treasury stock acquired from employees upon exercise of stock options and vesting of restricted stock	'	'	'	'	9,415	'
Treasury stock acquired from employees upon exercise of stock options and vesting of restricted stock (in shares)	'	'	'	'	305	'
Purchase of treasury stock	'	'	'	'	850,000	'
Purchase of treasury stock (in shares)	'	'	'	'	21,472	'
Tax benefit related to stock options exercised by employees	'	18	'	'	'	'
Stock-based compensation	'	59,317	'	'	'	59,317
Other comprehensive income (loss)	'	'	'	-10,930	'	'
Net income (loss)	'	'	979,058	'	'	979,058
Balance at Mar. 31, 2012	42,875	1,700,734	9,087,447	-2,934	5,151,305	'
Balance (in shares) at Mar. 31, 2012	428,746	'	'	'	160,640	'
Shares issued upon exercise of stock options and vesting of restricted stock	164	31,805	'	'	'	'
Shares issued upon exercise of stock options and vesting of restricted stock (in shares)	1,639	'	'	'	'	'
Treasury stock acquired from employees upon exercise of stock options and vesting of restricted stock	'	'	'	'	11,010	'
Treasury stock acquired from employees upon exercise of stock options and vesting of restricted stock (in shares)	'	'	'	'	308	'
Purchase of treasury stock (in shares)	'	'	'	'	2,938	'
Tax benefit related to stock options exercised by employees	'	1,807	'	'	'	'
Stock-based compensation	'	64,725	'	'	'	64,725
Other comprehensive income (loss)	'	'	'	13,050	'	'
Net income (loss)	'	'	-32,103	'	'	-32,103
Balance at Mar. 31, 2013	43,039	1,799,071	9,055,344	10,116	5,162,315	5,745,255
Balance (in shares) at Mar. 31, 2013	430,385	'	'	'	163,886	'
Shares issued upon exercise of stock options and vesting of restricted stock	598	172,536	'	'	'	'
Shares issued upon exercise of stock options and vesting of restricted stock (in shares)	5,983	'	'	'	'	'
Treasury stock acquired from employees upon exercise of stock options and vesting of restricted stock	'	'	'	'	9,591	'
Treasury stock acquired from employees upon exercise of stock options and vesting of restricted stock (in shares)	'	'	'	'	151	'
Tax benefit related to stock options exercised by employees	'	20,412	'	'	'	'
Stock-based compensation	'	69,051	'	'	'	69,051
Other comprehensive income (loss)	'	'	'	1,993	'	'
Net income (loss)	'	'	165,310	'	'	165,310
Balance at Mar. 31, 2014	$43,637	$2,061,070	$9,220,654	$12,109	$5,171,906	$6,165,564
Balance (in shares) at Mar. 31, 2014	436,368	'	'	'	164,037	'

CONSOLIDATED_STATEMENTS_OF_CAS

CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2012
Cash flows from operating activities:	'	'	'
Net income (loss)	$165,310	($32,103)	$979,058
Adjustments to reconcile net income (loss) to net cash provided by operating activities:	'	'	'
Depreciation, impairments and write-offs	136,423	47,270	40,952
Amortization	174,229	99,999	80,905
Stock-based compensation expense	69,051	64,725	59,317
Deferred income tax benefit and other non-cash tax items	-95,015	-26,752	-39,450
Decrease (increase) in:	'	'	'
Accounts receivable, net	23,256	-6,248	63,702
Inventories, net	-77,012	-95,783	162,166
Prepaid and other current assets	-231,440	8,247	62,685
Increase (decrease) in:	'	'	'
Accounts payable	30,775	3,074	-39,584
Accrued expenses	285,391	94,831	-6,140
Income tax liabilities	-38,864	-3,106	84,701
Other liabilities	9,262	-18,662	-11,000
Other assets	-6,372	-378	4,915
Other	25,909	0	0
Net cash provided by operating activities	470,903	135,114	1,442,227
Cash flows from investing activities:	'	'	'
Purchase of property, plant and equipment	-117,847	-64,384	-80,545
Sale of property, plant, and equipment	13,750	0	0
Purchase of marketable securities	-1,295,198	-3,476,059	-2,026,247
Redemption of marketable securities	1,854,900	2,968,734	2,697,149
Acquisitions	-2,900,000	0	-1,262,651
Purchase of trademarks	-275,471	-125,000	-469,364
Other investing activities	-52,232	-108,077	0
Net cash used in investing activities	-2,772,098	-804,786	-1,141,658
Cash flows from financing activities:	'	'	'
Proceeds from long-term debt	3,000,000	0	0
Net proceeds from common stock options exercised by employees under stock option plans	173,135	31,969	9,889
Tax benefit related to stock-based compensation	20,412	1,807	18
Treasury stock transactions	-9,591	-11,010	-859,415
Other financing activities	-40,976	0	0
Net cash provided by (used in) financing activities	3,142,980	22,766	-849,508
Effect of exchange rate changes on cash	2,576	3,066	-9,384
Increase (decrease) in cash and cash equivalents	844,361	-643,840	-558,323
Cash and cash equivalents, beginning of year	935,675	1,579,515	2,137,838
Cash and cash equivalents, end of year	1,780,036	935,675	1,579,515
Supplemental disclosures of cash flow information:	'	'	'
Cash paid for income taxes	$205,936	$64,267	$190,984

Summary_of_significant_account

Summary of significant accounting policies	12 Months Ended
	Mar. 31, 2014
Summary of significant accounting policies [Abstract]	'
Summary of significant accounting policies	'
	1. Summary of significant accounting policies:

	See accompanying notes to consolidated financial statements.

	Basis of presentation: The Consolidated Financial Statements are prepared in conformity with accounting principles generally accepted in the United States (GAAP) and include the accounts of Forest Laboratories, Inc. and its subsidiaries (“Forest,” “we,” “us,” or “the Company”) all of which are wholly-owned. All intercompany accounts and transactions have been eliminated.

	Estimates and assumptions: GAAP requires the Company to make estimates and assumptions that affect the reported amounts of assets and liabilities as of the end of each period and of revenues and expenses during the reporting periods. Situations where estimates are required to be made include, but are not limited to, accounting for business combinations, sales allowances, returns, rebates and other pricing adjustments, depreciation, amortization, tax assets and liabilities, restructuring reserves, and certain contingencies. Actual results may vary from estimates. The Company reviews all significant estimates affecting the financial statements on a recurring basis and records the effect of any adjustments when necessary.

	Reclassifications: Certain amounts as previously reported have been reclassified to conform to current year classifications.

	In the third quarter of fiscal 2014, the Company modified the presentation of its Consolidated Statements of Operations effective for all periods presented, whereby Interest income, interest expense and other miscellaneous income/expense is presented in the ‘Interest and other income (expense)’ caption below Operating income (loss). The modified presentation is consistent with industry practice and conforms with the requirements of Regulation S-X 5.03. There were no changes in the Company’s accounting policies, methodology for estimates or the activity included in the respective captions in the Consolidated Statements of Operations.

	Foreign currency translation: The statements of operations of the Company’s foreign subsidiaries are translated into U.S. dollars using average exchange rates for the applicable period. Gains and losses arising from foreign currency transactions are included in the statements of operations. The assets and liabilities of the Company’s foreign subsidiaries are translated into U.S. dollars using exchange rates at the end of the applicable period. The resulting translation adjustments arising from changes in the exchange rates are recorded in Accumulated other comprehensive income (loss) (AOCI).

	Cash equivalents: Cash equivalents consist of highly liquid investments purchased with maturities within three months of the purchase date which are readily convertible into cash.

	Inventories: Inventories are stated at the lower of cost or market, with cost determined on a first-in, first-out basis.

	Pre-launch inventories: The Company may accumulate commercial quantities of certain of its product candidates prior to the date it anticipates that such products will receive final U.S. Food and Drug Administration (FDA) approval. The accumulation of such pre-launch inventories involves the risk that such products may not be approved for marketing by the FDA on a timely basis, or ever. This risk notwithstanding, the Company may accumulate pre-launch inventories of certain products when such action is appropriate in relation to the commercial value of the product launch opportunity. In accordance with Company policy, this pre-launch inventory is expensed. At March 31, 2014 and 2013, the Company had no pre-launch inventories.

	Marketable securities: Marketable securities, which are all classified as available-for-sale, are stated at fair value based on quoted market prices in accordance with Accounting Standards Codification (ASC) 320, “Investments - Debt and Equity Securities”, and consist of high quality investments.

	Accounts receivable and credit policies: The carrying amount of accounts receivable is reduced to fair value by recording a valuation allowance that reflects management's best estimate of the amounts that will not be collected. In addition to reviewing delinquent accounts receivable, management considers many factors in estimating its general allowance, including historical data, experience, customer types, creditworthiness and economic trends. From time to time, management may adjust its assumptions for anticipated changes in any of those or other factors expected to affect collectability.

	Long-term receivables: Long-term receivables consist of balances that are due to the Company in a period greater than one year from the balance sheet date. As of March 31, 2014, Long-term receivables include note receivables of $101.9 million associated with the moksha8 agreement. Refer to Note 16 License and collaboration agreements for additional information.

	Property, plant and equipment and depreciation (estimated useful lives are stated in years): Property, plant and equipment (PP&E) are stated at cost. Depreciation is recorded using the straight-line method over the estimated useful life for each asset. As of March 31, 2014 and 2013, the Company’s PP&E balance and useful lives by category was as follows:

	(In thousands)

	Years ended March 31,		2014			2013			Depreciation period in years
	Land		$	26,827		$	32,740
	Buildings and improvements			183,427			294,370			Oct-50
	Machinery, equipment and other			427,584			373,385			10-Mar
	Construction in progress			62,412			39,207
	Property, plant and equipment			700,250			739,702
	Less: accumulated depreciation			328,435			362,742
	Property, plant and equipment, net		$	371,815		$	376,960

	Leasehold improvements are depreciated over the lesser of the useful life of the assets or the lease term. Included in property, plant and equipment at March 31, 2014 and 2013 is construction in progress of $62.4 million and $39.2 million, respectively, for facility expansion at one specific location necessary to support the Company’s current and future operations as well as upgrades to our data processing equipment. Projects currently in-process or under evaluation are estimated to cost approximately $67.7 million to complete. For construction in progress, depreciation commences once the asset is placed into service.

	Goodwill: Goodwill represents the excess of the fair value of the consideration transferred for an acquired business over the fair value of the identifiable net assets. The Company operates in only one segment. The Company completed its annual impairment assessments for the years ended March 31, 2014 and 2013 and concluded that goodwill was not impaired.

	Revenue recognition: Revenues are recorded in the period the merchandise is shipped. As is typical in the pharmaceutical industry, gross product sales are subject to a variety of deductions, primarily representing rebates and discounts to government agencies, wholesalers and managed care organizations. These deductions represent estimates of the related liabilities as judgment is required when estimating the impact of these sales deductions on gross sales for a reporting period. Historically, our adjustments for actual settlements have not been material. If estimates are not representative of actual future settlement, results could be materially affected.

	Provisions for estimated sales allowances, returns, rebates and other pricing adjustments are accrued at the time revenues are recognized as a direct reduction of such revenue. The accruals are estimated based on available information, including third party data regarding the portion of sales on which rebates and discounts can be earned, adjusted as appropriate for specific known events and the prevailing contractual discount rate. Provisions are reflected either as a direct reduction to accounts receivable or, to the extent that they are due to entities other than customers, as accrued expenses. Adjustments to estimates are recorded when Management becomes aware of a change of circumstances or when customer credits are issued or payments are made to third parties. There were no material adjustments to these estimates in the periods presented.

	Deductions for chargebacks (primarily discounts to group purchasing organizations and federal government agencies) closely approximate actual deductions as these deductions are settled generally within 2-3 weeks of incurring the liability.

	The sensitivity of estimates can vary by program and type of customer. However, estimates associated with Medicaid and contract rebates are most at risk for adjustment because of the extensive time delay between the recording of the accrual and its ultimate settlement, generally an interval that can range up to one year. Because of this time lag, in any given quarter, adjustments to actuals may incorporate revisions of prior quarters.

	Sales incentives are generally given in connection with new product launches. These sales incentives are recorded as a reduction of revenues and are based on terms fixed at the time goods are shipped. New product launches may result in expected temporary increases in wholesaler inventories, which are closely monitored and historically have not resulted in increased product returns.

	Shipping and handling costs: Presently, the Company does not charge its customers for any freight costs for domestic shipments in the ordinary course of business. The amounts of such costs are included in Selling, general and administrative (SG&A) expense and are not material.

	Research and development: Expenditures for Research and development (R&D), including upfront licensing fees and milestone payments (license payments) associated with developmental products that have not yet been approved by the FDA, are charged to R&D expense as incurred. License payments due to third parties upon, or subsequent to, FDA approval are recorded as intangible assets and classified as License agreements, product rights and other intangibles, net.

	Savings and profit sharing plans: Substantially all non-bargaining unit employees of the Company's domestic subsidiaries may participate in the savings and profit sharing plans after becoming eligible for the respective plan (as defined in each of the plans). In the Savings Plan, participants contribute a portion of their qualifying compensation each pay period, up to the allowable limit, and the Company provides a matching contribution as defined by the plan. For the Profit Sharing Plan, the Company makes contributions on an annual basis, which are allocated to participants as defined by the plan. All contributions made to the Profit Sharing Plan are at the discretion of the Company. Savings and profit sharing contributions amounted to approximately $43.5 million, $45.9 million and $43.4 million for fiscal years 2014, 2013 and 2012, respectively.

	Earnings (loss) per share: Basic earnings per share is computed by dividing net income available to common stockholders by the weighted average number of common shares outstanding for the period. Diluted earnings per share reflects, in periods in which they have a dilutive effect, the effect of common shares issuable upon the exercise of outstanding stock options and vesting of restricted stock. The weighted average number of diluted common shares outstanding is reduced by the treasury stock method which, in accordance with ASC 718 “Compensation – Stock Compensation”, takes into consideration the compensation cost attributable to future services not yet recognized.

	Accumulated other comprehensive income (loss): Other comprehensive income (loss) refers to revenues, expenses, gains and losses which are excluded from net income under GAAP. These amounts are recorded as an adjustment to AOCI, which is reflected as a separate component of equity. AOCI comprises the cumulative effects, net of taxes, of foreign currency translation, pension liability adjustments and unrealized gains (losses) on securities, and amounted to approximately $12.4 million, $(2.1) million and $1.8 million, respectively, at March 31, 2014 and $1.4 million, $(8.8) million and $17.5 million, respectively, at March 31, 2013.

Income taxes: The Company accounts for income taxes using the liability method. Under the liability method, deferred income taxes are provided on the differences in bases of assets and liabilities between financial reporting and tax returns using enacted tax rates.

Uncertain tax positions: The Company recognizes the tax benefit from an uncertain tax position only if it is more likely than not that the tax position will be sustained on examination by the taxing authorities, based on the technical merits of the position. The tax benefits recognized in the financial statements from such a position are measured based on the largest benefit that has a greater than 50 percent likelihood of being realized upon ultimate resolution.

Long-lived assets, other than goodwill: Long-lived assets, such as intangible assets and property, plant and equipment, are evaluated for impairment periodically or when events or changes in circumstances indicate that the carrying amount of the assets may not be recoverable through the estimated undiscounted future cash flows from the use of these assets. When any such impairment exists, a charge is recorded in the Statement of Operations in that period, to adjust the carrying value of the related asset. For the fiscal years ended March 31, 2014, 2013 and 2012, there were no such impairment charges recorded.

Stock-based compensation: The Company’s Compensation Committee and the Board of Directors awards stock options, restricted stock, and performance-based restricted stock units (PSUs) to employees and non-employee directors. The fair value of stock options is calculated using the Black-Scholes valuation model, restricted stock is accounted for at fair value based upon the stock price on the date of grant and PSUs, which contain market conditions, are valued using a Monte Carlo simulation model. These compensation costs are amortized on a straight-line basis (net of forfeitures) over the requisite service period.

Compensation expense of $69.1 million ($46.1 million net of tax), $64.7 million ($45.7 million net of tax), and $59.3 million ($44.3 million net of tax) was recorded for the fiscal years ended March 31, 2014, 2013 and 2012, respectively. This expense was charged to cost of sales, SG&A expense and R&D expense, as appropriate. Total compensation cost related to non-vested stock based awards not yet recognized as of March 31, 2014 was $125.0 million pre-tax and the weighted average period over which the cost is expected to be recognized is approximately 2.3 years.

The following weighted average assumptions were used in determining the fair values of stock options using the Black-Scholes model:

Year ended March 31,		2014			2013			2012
Expected dividend yield			0	%		0	%		0	%
Expected stock price volatility			23.26	%		25.1	%		27.49	%
Risk-free interest rate			1.5	%		1.2	%		1.4	%
Expected life of options (years)			7			7			7

The Company has never declared a cash dividend. The expected stock price volatility is based on implied volatilities from traded options on the Company’s stock as well as historical volatility. The risk-free interest rate is based on the U.S. Treasury yield curve in effect at the time of grant in conjunction with the expected life of options. The expected life is based upon historical data and represents the period of time that granted options are expected to be outstanding.

Collaboration arrangements: The Company accounts for collaboration arrangements in accordance with ASC 808 - “Collaborative Agreements” pursuant to which payments to and receipts from our collaboration partners are presented in our Consolidated Statements of Operations based on the nature of the arrangement (including its contractual terms), the nature of the payments and applicable guidance.

Business combinations: The Company accounts for business combinations under the acquisition method of accounting, which requires the assets acquired and liabilities assumed to be recorded at their respective fair values as of the acquisition date in the Company’s Consolidated Financial Statements. The determination of estimated fair value may require management to make significant estimates and assumptions. The purchase price is the fair value of the total consideration conveyed to the seller and the excess of the purchase price over the fair value of the acquired net assets, where applicable, is recorded as goodwill. The results of operations of an acquired business are included in our Consolidated Financial Statements from the date of acquisition. Costs associated with the acquisition of a business are expensed in the period incurred.

Debt: The Company’s carrying value of debt is principal, net of unamortized discount. Any costs associated with the issuance of debt is capitalized and amortized over the term of the debt.

Recent accounting standards: In April 2014, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) 2014-08, Presentation of Financial Statements (Topic 205) and Property, Plant, and Equipment (Topic 360): Reporting Discontinued Operations and Disclosures of Disposals of Components of an Entity. The amendments in this update will change the requirements for reporting discontinued operations. A discontinued operation may include a component of an entity, a group of components of an entity, or a business or nonprofit activity. A disposal of a component or a group of components is required to be reported in discontinued operations if the disposal represents a strategic shift that has (or will have) a major effect on an entity’s operations and financial results. This standard would become effective for the Company on April 1, 2015 and the adoption of this standard is not expected to have a significant impact on the Company’s financial statements.

Net_income_loss_per_share

Net income (loss) per share	12 Months Ended
Net income (loss) per share	Mar. 31, 2014
Net income (loss) per share [Abstract]	'
Net income (loss) per share	'
	2. Net income (loss) per share:

	A reconciliation of shares used in calculating basic and diluted net income per share follows:

	(In thousands)
	Years ended March 31,	2014		2013		2012
	Basic		269,129		266,807		273,561
	Incremental shares attributable to share based compensation plans		3,818		-		455
	Diluted		272,947		266,807		274,016

	Options to purchase approximately 1.3 million shares of common stock at exercise prices ranging from $42.61 to $96.42 per share were not included in the computation of diluted shares for the year ended March 31, 2014 because their effect would be anti-dilutive. These options expire through 2024. Options to purchase approximately 15.6 million shares of common stock at exercise prices ranging from $20.55 to $59.05 per share were not included in the computation of diluted shares for the year ended March 31, 2013 because their effect would be anti-dilutive. Options to purchase approximately 14.4 million shares of common stock at exercise prices ranging from $26.18 to $59.05 per share were not included in the computation of diluted shares for the year ended 2012 because their effect would be anti-dilutive.

	On November 26, 2013, the Board terminated the previously outstanding 50 million share repurchase authorization and authorized the repurchase of up to $1 billion of shares of common stock based on prevailing prices from time to time. The new authorization became effective immediately and has no set expiration date.

Business_operations

Business operations	12 Months Ended
Business operations	Mar. 31, 2014
Business operations [Abstract]	'
Business operations	'
	3. Business operations:

	The Company and its principal operating subsidiaries, which are located primarily in the U.S. and Europe, manufacture and market ethical pharmaceutical products and other healthcare products. The Company operates in only one segment. Sales are primarily in the U.S. and European markets. The net sales and long-lived assets for the years ended March 31, 2014, 2013 and 2012, are from the Company’s or one of its subsidiaries’ country of origin, as follows:

	(In thousands)	2014						2013					2012
		Net sales			Long-lived assets			Net sales			Long-lived assets		Net sales		Long-lived assets
	U.S.	$	3,329,367		$	707,784		$	2,769,541		$	432,085	$	4,261,976	$	386,427
	Ireland		74,360			3,949,311			60,014			2,759,428		61,747		2,759,069
	United Kingdom		76,043			23,608			75,381			26,177		68,825		31,663
	Canada		5,725			1,792,332			-			-		-		-
	Italy		8,166			78,356			-			-		-		-
	Other		9,685			29,871			-			-		-		-
		$	3,503,346		$	6,581,262		$	2,904,936		$	3,217,690	$	4,392,548	$	3,177,159

	Net sales exclude sales between the Company and its subsidiaries.

	Net sales by therapeutic class are as follows:

	(In thousands)
	Years ended March 31,	2014			2013			2012
	Central nervous system (CNS)	$	2,124,573		$	2,017,199		$	3,715,112
	Cardiovascular		553,092			483,733			381,621
	Gastrointestinal		265,127			23,728			-
	Respiratory		207,536			100,920			31,203
	Other		353,018			279,356			264,612
		$	3,503,346		$	2,904,936		$	4,392,548

	The Company’s CNS franchise consisting of Campral®, Celexa®, Fetzima®, Lexapro®, Namenda®, Namenda XR®, Savella®, Saphris® and Viibryd® accounted for 61%, 69% and 85% of the Company’s net sales for the years ended March 31, 2014, 2013 and 2012, respectively.

	The following illustrates net sales to the Company’s principal customers:

		2014			2013			2012
	McKesson Drug Company		37	%		38	%		36	%
	AmerisourceBergen Corporation		26	%		20	%		20	%
	Cardinal Heath, Inc.		22	%		29	%		30	%

Accounts_receivable

Accounts receivable	12 Months Ended
Accounts receivable	Mar. 31, 2014
Accounts receivable [Abstract]	'
Accounts receivable	'
	4. Accounts receivable:

	Accounts receivable, net, consists of the following:

	(In thousands)
	As of March 31,	2014		2013
	Trade	$	514,836	$	403,331
	Other		62,018		74,701
		$	576,854	$	478,032

Inventories

Inventories	12 Months Ended
Inventories	Mar. 31, 2014
Inventories [Abstract]	'
Inventories	'
	5. Inventories:

	Inventories, net of reserves for obsolescence, consist of the following:

	(In thousands)
	As of March 31,	2014		2013
	Raw materials	$	181,168	$	127,508
	Work in process		23,451		1,333
	Finished goods		408,045		265,060
		$	612,664	$	393,901

Fair_value_measurements

Fair value measurements	12 Months Ended
Fair value measurements	Mar. 31, 2014
Fair value measurements [Abstract]	'
Fair value measurements	'
	6. Fair value measurements:

	ASC 820, “Fair Value Measurements and Disclosures”, defines fair value as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date under current market conditions. The standard also requires the use of a fair value hierarchy that prioritizes inputs to fair value measurement techniques into three broad levels. The following is a brief description of those three levels:

		Level 1:	Observable inputs such as quoted prices for identical assets or liabilities in active markets.

		Level 2:	Observable inputs other than quoted prices that are directly or indirectly observable for the asset or liability, including quoted prices for similar assets or liabilities in active markets; quoted prices for similar or identical assets or liabilities in markets that are not active; and model-derived valuations whose inputs are observable or whose significant value drivers are observable.

		Level 3:	Unobservable inputs that reflect the reporting entity’s own assumptions.

	The Company’s financial assets are measured at fair value and include its commercial paper investments, money market accounts, municipal bonds and notes, government agency bonds, corporate bonds, certificates of deposit, variable rate demand notes, floating rate notes and auction rate securities (ARS). These assets are subject to the measurement and disclosure requirements of ASC 820.

	The following table presents the level within the fair value hierarchy at which the Company’s financial assets are carried at fair value and measured on a recurring basis:

	(In thousands)		Fair value at			Quoted prices in active markets for identical assets		Significant other observable market inputs		Unobservable market inputs
			31-Mar-14			(Level 1)		(Level 2)		(Level 3)
	Description
	Money market accounts		$	1,030,599		$	1,030,599		-		-
	Municipal bonds and notes			12,357			-	$	12,357		-
	Commercial paper			242,805			2,850		239,955		-
	Variable rate demand notes			30,770			-		30,770		-
	Auction rate securities			3,123			-		-	$	3,123
	Certificates of deposit			32,988			-		32,988		-
	Corporate bonds			1,225,619			-		1,225,619		-
	Government agency bonds			111,304			-		111,304		-


	(In thousands)		Fair value at			Quoted prices in active markets for identical assets		Significant other observable market inputs		Unobservable market inputs
			31-Mar-13			(Level 1)		(Level 2)		(Level 3)
	Description
	Money market accounts		$	818,474		$	818,474		-		-
	Municipal bonds and notes			46,877			-	$	46,877		-
	Commercial paper			168,639			31,815		136,824		-
	Variable rate demand notes			1,500			-		1,500		-
	Auction rate securities			3,198			-		-	$	3,198
	Certificates of deposit			90,268			5,981		84,287		-
	Corporate bonds			1,509,870			-		1,509,870		-
	Government agency bonds			278,804			-		278,804		-

	The Company determines fair value based on a market approach using quoted market values, significant other observable inputs for identical or comparable assets or liabilities, or discounted cash flow analyses.

	The following table presents a reconciliation of the Level 3 investments measured at fair value on a recurring basis using unobservable inputs:

	(In thousands)		Year ended
	(In thousands)		31-Mar-14
	Balance at beginning of period		$	3,198
	Sales			(75	)
	Unrealized gain/(loss)			-
	Balance at end of period		$	3,123

	There were no purchases or realized gains or losses within the Level 3 ARS during the years ended March 31, 2014 and 2013. The Company recorded sales of $0.1 million of its Level 3 ARS for the period ended March 31, 2014.

	At March 31, 2014, the Company held investments in ARS amounting to $3.1 million (with underlying maturities of 20 years) of which the entire balance is collateralized by student loans. Substantially all such collateral in the aggregate is guaranteed by the U.S. government under the Federal Family Education Loan Program.

	All money market accounts are classified as Level 1 assets. Certain commercial paper investments and certificates of deposit are also classified as Level 1 assets because they consist of publicly traded securities which are priced and actively traded on a daily basis.

	Certain of the Company’s commercial paper and certificates of deposit and all of the Company’s variable rate demand notes, municipal bonds and notes, corporate bonds and government agency bonds are based on Level 2 inputs in the ASC 820 fair value hierarchy.

	In addition to the above, the Company also has Level 3 fair value measurements related to the Aptalis and Clinical Data, Inc. (Clinical Data) acquisitions; see Note 17 for further information.

	The Company issued long-term debt with a carrying value of $3.0 billion during fiscal 2014; see Note 10 for further information.

	The majority of the Company’s non-financial assets and liabilities are not required to be carried at fair value on a recurring basis. However, the Company is required on a non-recurring basis to use fair value measurements when analyzing asset impairment as it relates to goodwill, license agreements, product rights, IPR&D, and other intangible assets and long-lived assets. The carrying amount of cash, accounts receivable, loans receivable and accounts payable and other short-term financial instruments approximate their fair value due to their short-term nature.

Marketable_securities

Marketable securities	12 Months Ended
Marketable securities	Mar. 31, 2014
Marketable securities [Abstract]	'
Marketable securities	'
	7. Marketable securities:

	Available-for-sale debt securities consist of the following:

			31-Mar-14
	(In thousands)				Gains in accumulated other comprehensive income		Losses in accumulated other comprehensive income


			Estimated fair value

	Current:
	Municipal bonds and notes		$	7,066	$	6	$	-
	Government agency bonds			24,802		24		(6	)
	Commercial paper			82,950		-		-
	Certificates of deposit			25,989		-		-
	Corporate bonds			232,207		488		(38	)
	Total current securities			373,014		518		(44	)

	Non-current:
	Municipal bonds and notes			5,291		22		-
	Government agency bonds			86,502		127		(146	)
	Commercial paper			2,850		-		-
	Certificates of deposit			3,000		-		-
	Corporate bonds			986,265		3,297		(2,126	)
	Auction rate notes			3,123		-		(752	)
	Variable rate notes			30,770		-		-
	Total non-current securities			1,117,801		3,446		(3,024	)

	Total available-for-sale debt securities		$	1,490,815	$	3,964	$	(3,068	)

			31-Mar-13
	(In thousands)				Gains in accumulated other comprehensive income		Losses in accumulated other comprehensive income


			Estimated fair value

	Current:
	Municipal bonds and notes		$	34,025	$	34	$	-
	Government agency bonds			87,227		125		(10	)
	Commercial paper			144,293		-		-
	Certificates of deposit			47,977		-		(2	)
	Corporate bonds			425,676		1,286		(33	)
	Total current securities			739,198		1,445		(45	)

	Non-current:
	Municipal bonds and notes			12,852		37		-
	Government agency bonds			186,577		434		(19	)
	Certificates of deposit			22,999		-		-
	Corporate bonds			1,084,194		5,290		(2,150	)
	Auction rate notes			3,198		-		(752	)
	Variable rate notes			1,500		-		-
	Total non-current securities			1,311,320		5,761		(2,921	)

	Total available-for-sale debt securities		$	2,050,518	$	7,206		(2,966	)

	Proceeds from the sales of available-for-sale debt securities were $1.9 billion and $3.0 billion during fiscal years 2014 and 2013, respectively. Gross realized gains on those sales during fiscal years 2014 and 2013 were $1.7 million and $1.3 million, respectively. In order to determine gross realized gains and losses, the Company uses average cost. The Company records holding gains and losses on available for sale securities in the ‘Accumulated other comprehensive income’ caption in the consolidated Balance Sheet. The Company had a net unrealized gain of $0.9 million and $4.2 million at March 31, 2014 and 2013, respectively. The preceding does not include the Company’s equity securities for Ironwood Pharmaceuticals, Inc. (Ironwood) and Trevena, Inc. (Trevena). The carrying value of the Company’s equity securities in Ironwood, which were measured at fair market value based on quoted market prices for the related security, was $25.7 million and $38.1 million at March 31, 2014 and 2013, respectively. The Company purchased $30 million of Trevena preferred stock in a round of private placement financing during the first quarter of fiscal 2014. This investment was accounted for using the cost method. During the fourth quarter of fiscal 2014, Trevena filed an Initial Public Offering (IPO), and as a result, the Company’s preferred stock converted to common shares. In conjunction with the IPO, the Company purchased an additional $3.0 million of common stock. The fair value of Trevena common stock held at March 31, 2014 was $26.7 million.

	Contractual maturities of available-for-sale debt securities at March 31, 2014 are as follows:

	(In thousands)
			Estimated fair value
	Within one year		$	373,014
	1-5 years			1,078,986
5-10 years			2,300
After 10 years			36,515
		$	1,490,815

Actual maturities may differ from contractual maturities because some borrowers have the right to call or prepay obligations with or without call penalties.

The Company invests funds in variable rate demand notes that have major bank liquidity agreements, municipal bonds and notes, government agency bonds, commercial paper, corporate bonds, certificates of deposit, and auction rate securities. Certain securities are subject to a hard-put option(s) where the principal amount is contractually assured by the issuer and any resistance to the exercise of these options would be deemed as a default by the issuer. Such a potential default would be reflected in the issuer’s respective credit rating, for which the Company maintains investment grade requirements pursuant to its corporate investment guidelines. While the Company believes its investments that have net unrealized losses are temporary, declines in the value of these investments may be deemed other-than-temporary if the credit and capital markets were to deteriorate in future periods. The Company has the ability and intends to hold its investments until a recovery of fair value, which may be at maturity. The Company does not consider these investments to be other-than-temporarily impaired and will continue to monitor global market conditions to minimize the risk of impairments in future periods.

Goodwill_and_intangible_assets

Goodwill and intangible assets	12 Months Ended
Goodwill and intangible assets	Mar. 31, 2014
Goodwill and intangible assets [Abstract]	'
Goodwill and intangible assets	'
	8. Goodwill and intangible assets:

	The changes in the carrying amount of goodwill for the years ended March 31, 2014 and 2013 are as follows:

	(In thousands)	Gross carrying amount
	Balance at March 31, 2012	$	713,091
	Acquisitions/Dispositions		-
	Balance at March 31, 2013		713,091
	Acquisition of Aptalis		335,417
	Balance at March 31, 2014	$	1,048,508

	License agreements, product rights and other intangibles consist of the following:

	(In thousands)	31-Mar-14				31-Mar-13
		Gross carrying amount		Accumulated amortization		Gross carrying amount		Accumulated amortization
	Amortized intangible assets:
	License agreements	$	1,803,425	$	249,088	$	1,528,114	$	160,805
	Product rights		3,005,025		98,903		89,407		61,472
	Buy-out of royalty agreements		798,617		114,737		798,617		66,222
	In process research and development		16,600		-		-		-
	Trade names		34,190		34,190		34,190		34,190
	Total	$	5,657,857	$	496,918	$	2,450,328	$	322,689

	During the year ended March 31, 2014, intangible additions included $2.9 billion of Product rights and $16.6 million of IPR&D related to the acquisition of Aptalis (refer to Note 17 Business combinations for additional information) and $231 million of License agreements related to the purchase of exclusive rights in the U.S. for Saphris® (asenapine) from Merck & Co., Inc. (Merck) (refer to Note 16 License and collaboration agreements for additional information).

	Amortization of license agreements, product rights and other intangibles charged to SG&A expense and cost of goods sold for the fiscal years ended March 31, 2014, 2013 and 2012 amounted to approximately $174.2 million, $99.9 million and $80.9 million, respectively. Future annual amortization expense expected is as follows:

	(In thousands)
	Years ended March 31,
	2015	$	369,673
	2016		419,438
	2017		432,454
	2018		483,149
	2019		526,084
		$	2,230,798

Accrued_expenses

Accrued expenses	12 Months Ended
Accrued expenses	Mar. 31, 2014
Accrued expenses [Abstract]	'
Accrued expenses	'
	9. Accrued expenses:

	Accrued expenses consist of the following:

	(In thousands)
	As of March 31,	2014		2013
	Managed care and Medicaid rebates	$	302,389	$	230,173
	Employee compensation and other benefits		211,753		181,995
	Clinical research and development costs		172,122		129,663
	Restructuring		74,104		-
	Other		529,276		298,511
		$	1,289,644	$	840,342

Debt_and_debt_facility

Debt and debt facility	12 Months Ended
Debt and debt facility	Mar. 31, 2014
Debt and debt facility [Abstract]	'
Debt and debt facility	'
	10. Debt and debt facility:

	On January 31, 2014 the Company issued $1.8 billion aggregate senior unsecured notes (the $1.8 billion Senior Notes), comprised of $1.05 billion aggregate principal amount of 4.375% senior unsecured notes due 2019 and $750 million aggregate principal amount of 4.875% senior unsecured notes due 2021. The Company will pay interest on the $1.05 billion of senior unsecured notes at 4.375% per annum, semi-annually in arrears on February 1 and August 1, commencing on August 1, 2014. The Company will pay interest on the $750 million of senior unsecured notes at 4.875% per annum, semi-annually in arrears on February 15 and August 15, commencing on August 15, 2014. The Company incurred $22.5 million in deferred financing costs associated with the $1.8 Senior Notes which will be amortized over the term of the notes. For the fiscal year ended March 31, 2014, the Company recorded $11.8 million of interest expense and $0.6 million of amortization of deferred financing fees related to the $1.8 Senior Notes. At March 31, 2014, the fair value of the $1.8 Senior Notes was $1.9 billion which was determined using Level 2 inputs based on a market approach.

	On December 10, 2013 the Company issued $1.2 billion of 5.00% Senior Notes (the 5.00% Senior Notes), which mature on December 15, 2021. The 5.00% Senior Notes accrue interest per annum, payable semi-annually in arrears on June 15 and December 15, commencing on June 15, 2014. The Company incurred $18.5 million in deferred financing costs associated with the 5.00% Senior Notes which will be amortized over the term of the notes. For the fiscal year ended March 31, 2014, the Company recorded $18.4 million of interest expense and $0.7 million of amortization of deferred financing fees related to the 5.00% Senior Notes. At March 31, 2014, the fair value of the 5.00% Senior Notes was $1.3 billion which was determined using Level 2 inputs based on a market approach.

	On December 4, 2012, the Company established a $750 million revolving credit facility for the purpose of providing financial liquidity for financing strategic business development and general corporate purposes. This revolving credit facility expires on December 4, 2017. The facility can be increased to $1.0 billion based upon agreement with the participating lenders. As of May 29, 2014, the total availability under our Credit Agreement was $750 million, excluding $8.5 million of issued letters of credit. The utilization of the revolving credit facility is subject to the adherence to certain financial covenants such as leverage and interest coverage ratios. As of March 31, 2014, the Company is in compliance with all covenants.

Commitments

Commitments	12 Months Ended
	Mar. 31, 2014
Commitments [Abstract]	'
Commitments	'
	11. Commitments:

	Leases: The Company leases manufacturing, laboratory, office and warehouse facilities, equipment and automobiles under operating leases expiring through fiscal 2027. Rent expense was approximately $51.1 million, $45.3 million and $39.5 million for fiscal years ended March 31, 2014, 2013 and 2012, respectively. Future minimum rental payments under non-cancellable leases are as follows:


	(In thousands)
	Years ended March 31,
	2015	$	45,874
	2016		36,074
	2017		28,757
	2018		20,084
	2019		14,589
	Thereafter		84,120
		$	229,498

	License agreements: The Company has entered into several license and collaboration agreements for products currently under development. Pursuant to these agreements, the Company may be obligated in future periods to make additional development milestone payments. These milestone payments may never occur as they are contingent on the achievement of future clinical developments which may never be attained. As of March 31, 2014, the total of all potential future development milestone payments was approximately $552 million. This consisted of milestones payable upon the achievement of certain specific research and development milestones of approximately $183 million and milestones payable upon the achievement of regulatory approval of approximately $369 million.

	In addition, the Company may also be obligated to pay commercial milestones contingent upon the achievement of specific sales levels. Similarly, these milestone payments may never occur as they are contingent on the achievement of future commercial success which may never be attained. For commercially launched products, the total of all potential future commercial milestones as of March 31, 2014 was approximately $340 million.

	Inventory purchase commitments and other: The Company has inventory purchase and other commitments of $169.3 million as of March 31, 2014.

Stockholders_equity

Stockholders' equity	12 Months Ended
Stockholders' equity	Mar. 31, 2014
Stockholders' equity [Abstract]	'
Stockholders' equity	'
	12. Stockholders' equity:

	In August 2013, the Company’s stockholders approved an amendment to the Company’s 2007 Equity Incentive Plan (the 2007 Plan) whereby an additional 28 million shares were authorized to be issued to employees of the Company. Under the 2007 Plan as amended in August 2013, 57 million shares have been authorized to be issued to employees of the Company and its subsidiaries at prices not less than the fair market value of the common stock at the date of grant. The 2007 Plan provides for the granting of incentive and nonqualified stock options, restricted stock, stock appreciation rights and stock equivalent units. These awards generally vest in three to five years. Stock option grants may be exercisable for up to ten years from the date of issuance. At March 31, 2014, 31.6 million shares were available for grant under the 2007 Plan.

	The following table summarizes information about stock options outstanding at March 31, 2014:

				Options outstanding												Options exercisable
	Range of exercise prices			Number				Weighted average remaining contractual life				Weighted average exercise price				Number		Weighted average exercise price
	Range of exercise prices			outstanding				(in years)				Weighted average exercise price				exercisable		Weighted average exercise price

	$20.55 to $30.00				2,364				6.8			$	28.24				1,218	$	26.9
	30.01 to 50.00				9,504				7.2				36.49				3,169		36.04
	50.01 to 96.42				582				4.3				54.55				448		51.54
					12,450				7				35.77				4,835		35.17

	Transactions under the stock option plan are summarized as follows:

	(In thousands)	Options				Weighted average			Weighted	Aggregate
						exercise price			average	intrinsic value
									remaining
									contractual life
									(in years)
	Stock options:
	Outstanding at March 31, 2011 (at $20.55 to $63.44 per share)		17,085			$	36.9
	Granted (at $30.00 to $34.49 per share)		3,758				31.04
	Exercised (at $20.55 to $39.88 per share)		(351	)			28.19
	Forfeited and Expired		(3,249	)			39.89

	Outstanding at March 31, 2012 (at $20.55 to $59.05 per share)		17,243			$	35.24
	Granted (at $34.04 to $38.10 per share)		2,368				34.26
	Exercised (at $31.28 to $38.45 per share)		(1,137	)			28.52
	Forfeited and Expired		(2,923	)			43.7

	Outstanding at March 31, 2013 (at $20.55 to $59.05 per share)		15,551			$	34.03
	Granted (at $37.88 to $96.42 per share)		4,155				40.31
	Exercised (at $35.34 to $100.66 per share)		(5,261	)			32.91
	Forfeited and Expired		(1,995	)			39.27

	Outstanding at March 31, 2014 (at $20.55 to $96.42 per share)		12,450			$	35.77		7	$703,525

	Exercisable at March 31, 2014		4,835			$	35.17		4.9	$276,098

		Restricted Stock								Performance Stock Units
		Shares/ Units				Weighted average grant date fair value				Units				Weighted average grant date fair value
	Restricted stock:
	Outstanding at March 31, 2011		2,275			$	30.72
	Granted		1,239				30.43
	Vested		(928	)			30.66
	Forfeited		(101	)			30.62

	Outstanding at March 31, 2012		2,485			$	30.6				-				-
	Granted		613				34.27				410			$	36.12
	Vested		(1,047	)			30.13				-				-
	Forfeited		(88	)			31.86				-				-

	Outstanding at March 31, 2013		1,963			$	31.96				410			$	36.12
	Granted		1,133				40.68				217				45.35
	Vested		(973	)			31.77				-				-
	Forfeited		(395	)			34.79				(49	)			39.96

	Outstanding at March 31, 2014		1,728			$	37.14				578			$	36.04

	The total intrinsic value of stock options exercised during the years ended March 31, 2014, 2013 and 2012 was $166.2 million, $8.7 million and $2.5 million, respectively, and the total intrinsic value of restricted stock vested during the years ended March 31, 2014, 2013 and 2012 was $51.8 million, $37.5 million and $28.6 million, respectively. The weighted average grant date fair value per stock option granted during the years ended March 31, 2014, 2013 and 2012 were $11.42, $10.04 and $9.68, respectively. The total cash received as a result of stock option exercises for the years ended March 31, 2014, 2013 and 2012 was approximately $173.1 million, $32.0 million and $9.9 million, respectively. In connection with these exercises, the Company recorded a net tax benefit of $20.4 million for the year ended March 31, 2014, a net tax benefit of $1.8 million for the year ended March 31, 2013 and a net tax benefit of $0.02 million, for the year ended March 31, 2012. The Company settles employee stock option exercises and restricted stock releases with newly issued common shares.

Contingencies

Contingencies	12 Months Ended
Contingencies	Mar. 31, 2014
Contingencies [Abstract]	'
Contingencies	'
	13. Contingencies:

	The Company is subject to the various legal proceedings and claims discussed below as well as certain other legal proceedings and claims that have not been fully resolved and that have arisen in the ordinary course of business. Although we believe that the proceedings brought against us are without merit and in certain instances we have insurance, litigation is subject to significant uncertainty and there can be no assurance that we will not incur material costs in the resolution of these matters.

	Average Wholesale Price Litigation

	We are defendants in four state court actions that allege that the plaintiffs (all governmental entities) were overcharged for their share of Medicaid drug reimbursement costs as a result of reporting by manufacturers of “average wholesale prices” (AWP) that did not correspond to actual provider costs of prescription drugs. These actions are pending in Illinois (commenced February 7, 2005), Mississippi (commenced October 20, 2005), Utah (commenced May 2008), and Wisconsin (a qui tam AWP action commenced by the former Attorney General of the State of Wisconsin on February 20, 2012 that the State declined to join). Discovery is ongoing in these actions. On November 15, 2013, the plaintiff in the Mississippi action moved for leave to file a Second Amended Complaint. On March 26, 2014, the Mississippi state court granted plaintiff’s motion in part, but denied plaintiff’s request to add generic drug products to its claims. Forest has filed a motion to dismiss certain of the claims asserted in the Second Amended Complaint. A trial in the Mississippi action is scheduled in October 2014. A motion to dismiss the Utah action was granted, but the Utah Supreme Court, while upholding the lower court’s ruling regarding a statute of limitations issue, reversed that ruling and allowed the plaintiff to replead. The plaintiff filed another Amended Complaint, and the defendants filed a motion to dismiss. This motion to dismiss was denied in part. On February 17, 2014, the Wisconsin state court granted defendants’ motion to dismiss plaintiff’s Second Amended Complaint. On April 14, 2014, plaintiff filed a motion for leave to file a Third Amended Complaint, and on May 16, 2014, plaintiff filed an appeal of the court’s February 17, 2014 ruling. We intend to continue to vigorously defend against these actions. At this time, we are unable to estimate the reasonably possible loss or range of possible loss, but do not believe losses, if any, would have a material effect on the results of operations or financial position taken as a whole.

	Celexa/Lexapro Class Actions

	We are defendants in three federal court actions filed on behalf of individuals who purchased Celexa and/or Lexapro for pediatric use, all of which have been consolidated for pretrial purposes in a Multi-District Litigation (MDL) proceeding in the U.S. District Court for the District of Massachusetts under the caption “In re Celexa and Lexapro Marketing and Sales Practices Litigation.” These actions, two of which were originally filed as putative nationwide class actions, and one of which is a putative California-wide class action, allege that Forest marketed Celexa and/or Lexapro for off-label pediatric use and paid illegal kickbacks to physicians to induce prescriptions of Celexa and Lexapro. The complaints assert various similar claims, including claims under the Missouri and California consumer protection statutes, respectively, and state common laws. On February 5, 2013, the district judge overseeing the MDL denied all plaintiffs’ motions for class certification. On February 18, 2013, the plaintiff in the California action filed a petition seeking leave to appeal this decision to the U.S. Court of Appeals for the First Circuit. On April 16, 2013, the First Circuit denied the petition. On April 30, 2013, plaintiffs in the other two actions filed an Amended Complaint seeking to certify state-wide class actions in Illinois, Missouri, and New York under those states’ consumer protection statutes. On January 13, 2014, the district judge denied plaintiffs’ motion with respect to the proposed Illinois and New York classes and allowed it with respect to the proposed Missouri class. We filed a petition seeking leave to appeal this decision to the U.S. Court of Appeals for the First Circuit on January 27, 2014. On March 12, 2014, we reached agreement with the MDL plaintiffs to settle the Missouri class claims, including claim by both individuals and third party payors that purchased Celexa or Lexapro for use by a minor from 1998 to December 31, 2013. In exchange for a release from class members, we will pay $7.65 million into a fund that will cover (1) the settlement benefits paid to class members, (2) administration costs, (3) incentive awards to be paid to the representative plaintiffs, and (4) attorneys’ fees and costs. If valid claims are greater than $4.215 million, we will pay up to $2.7 million more to pay for the additional valid claims (our total settlement payment shall not exceed $10.35 million). The district court judge preliminarily approved the settlement on March 14, 2014 and issued an order enjoining all class members and other persons from litigating claims relating to those covered by the settlement. A hearing on whether the court should grant final approval of the settlement is scheduled for July 16, 2014.

	On May 3, 2013, another action was filed in the U.S. District Court for the Central District of California on behalf of individuals who purchased Lexapro for adolescent use, seeking to certify a state-wide class action in California and alleging that our promotion of Lexapro for adolescent depression has been deceptive. This action was transferred to the MDL mentioned in the preceding paragraph and, on July 29, 2013, we moved to dismiss the complaint. The district court judge granted our motion to dismiss on March 5, 2014. Plaintiff filed a Notice of Appeal with the U.S. Court of Appeals for the First Circuit on March 17, 2014.

	On November 13, 2013, another action was filed in the U.S. District Court for the District of Minnesota seeking to certify a nationwide class of third-party payor entities that purchased Celexa and Lexapro for pediatric use. The complaint asserts claims under the federal Racketeer Influenced and Corrupt Organizations Act, alleging that Forest engaged in an off-label marketing scheme and paid illegal kickbacks to physicians to induce prescriptions of Celexa and Lexapro. This action was transferred to the MDL mentioned in the preceding paragraphs, and we filed a motion to dismiss the complaint on January 15, 2014. On February 5, 2014, the plaintiffs voluntarily dismissed the complaint and filed a First Amended Complaint, which, among other things, added claims on behalf of a Minnesota class of entities and consumers under Minnesota’s consumer protection statutes. We filed a motion to dismiss the First Amended Complaint on April 9, 2014.

	On March 13, 2014, an action was filed in the U.S. District Court for the District of Massachusetts by two third-party payors seeking to certify a nationwide class of persons and entities that purchased Celexa and Lexapro for use by pediatric use. The complaint asserts claims under the federal Racketeer Influenced and Corrupt Organizations Act, state consumer protection statutes, and state common laws, alleging that Forest engaged in an off-label marketing scheme and paid illegal kickbacks to physicians to induce prescriptions of Celexa and Lexapro. This action was filed as a related action to the action described above in the preceding paragraph. We filed a motion to dismiss the complaint on April 30, 2014.

	We intend to continue to vigorously defend against these actions. At this time, we are unable to estimate the reasonably possible loss or range of possible loss, but do not believe losses, if any, would have a material effect on the results of operations or financial position taken as a whole.

	We are also named as defendants in two actions filed on behalf of entities or individuals who purchased or reimbursed certain purchases of Celexa and Lexapro for pediatric use pending in the Missouri Circuit Court, Twenty-Second Judicial Circuit, and arising from similar allegations as those contained in the federal actions described in the preceding paragraphs. The first action, filed on November 6, 2009 under the caption “St. Louis Labor Healthcare Network et al. v. Forest Pharmaceuticals, Inc. and Forest Laboratories, Inc.,” is brought by two entities that purchased or reimbursed certain purchases of Celexa and/or Lexapro. The complaint asserts claims under the Missouri consumer protection statute and Missouri common law, and seeks unspecified damages and attorneys’ fees. We have reached an agreement with the plaintiffs to resolve this action for payments that are not material to our financial condition or results of operations. The second action, filed on July 22, 2009 under the caption “Crawford v. Forest Pharmaceuticals, Inc.,” and now known as “Luster v. Forest Pharmaceuticals, Inc.,” is a putative class action on behalf of a class of Missouri citizens who purchased Celexa for pediatric use. The complaint asserts claims under the Missouri consumer protection statute and Missouri common law, and seeks unspecified damages and attorneys’ fees. In October 2010, the court certified a class of Missouri domiciliary citizens who purchased Celexa for pediatric use at any time prior to the date of the class certification order, but who do not have a claim for personal injury. On December 9, 2013, we filed a motion for summary judgment, which was argued on January 8, 2014. On February 21, 2014, we filed a motion to de-certify the class. Decisions on these motions are pending. On March 12, 2014, we informed the judge of the MDL Missouri class settlement described above, including that the federal class encompasses the members of the certified Missouri class in Luster. At a status conference on April 2, 2014 the parties agreed that the action is stayed in light of the injunction contained in the MDL Preliminary Approval Order, described above. We intend to continue to vigorously defend against this action. At this time, we are unable to estimate the reasonably possible loss or range of possible loss, but do not believe losses, if any, would have a material effect on the results of operations or financial position taken as a whole.

	Employment Litigation

	In July 2012, we were named as defendants in an action brought by Megan Barrett, Lindsey Houser, Jennifer Jones, and Jennifer Seard, former Company Sales Representatives, in the U.S. District Court for the Southern District of New York under the caption “Megan Barrett et al. v. Forest Laboratories Inc. and Forest Pharmaceuticals, Inc.” In November 2012, Plaintiffs amended the complaint, adding six additional plaintiffs: Kimberly Clinton, Erin Eckenrode, Julie Smyth, Marie Avila, Andrea Harley, and Christy Lowder, all of whom alleged that they were current or former Company Sales Representatives or Specialty Sales Representatives. In March 2013, Plaintiffs filed a Second Amended Complaint, adding one additional plaintiff: Tracy Le, a now-former Company Sales Representative. The action is a putative class and collective action, and the Second Amended Complaint alleges class claims under Title VII for gender discrimination with respect to pay and promotions, as well as discrimination on the basis of pregnancy, and a collective action claim under the Equal Pay Act. The proposed Title VII gender class includes all current and former female Sales Representatives (defined to include Territory Sales Representatives, Field Sales Representatives, Medical Sales Representatives, Professional Sales Representatives, Specialty Sales Representatives, Field Sales Trainers, and Regional Sales Trainers) employed by the Company throughout the U.S. from 2008 to the date of judgment, and the proposed Title VII pregnancy sub-class includes all current and former female Sales Representatives who have been, are, or will become pregnant while employed by the Company throughout the U.S. from 2008 to the date of judgment. The proposed Equal Pay Act collective action class includes current, former, and future female Sales Representatives who were not compensated equally to similarly-situated male employees during the applicable liability period. The Second Amended Complaint also includes non-class claims on behalf of certain of the named Plaintiffs for sexual harassment and retaliation under Title VII, and for violations of the Family and Medical Leave Act. We filed a motion to dismiss certain claims on April 29, 2013, which was argued on January 16, 2014. We intend to continue to vigorously defend against this action. At this time, we are unable to estimate the reasonably possible loss or range of possible loss, but do not believe losses, if any, would have a material effect on the results of operations or financial position taken as a whole.

	Government Investigations

	We received a subpoena dated April 20, 2011 from the Office of the U.S. Attorney for the District of Massachusetts. The subpoena requests documents relating to Benicar, Benicar HCT, and Azor, prescription medications approved for the treatment of hypertension. We co-marketed Benicar and Benicar HCT from 2002 to 2008, and Azor from 2007 to 2008, together with the drug’s originator Sankyo under co-promotion agreements. We are cooperating in responding to the subpoena.

	We received a subpoena dated May 6, 2013 from the Office of the U.S. Attorney for the Southern District of New York. The subpoena requests documents relating to the marketing and promotion of Tudorza Pressair, including with respect to speaker programs for this product. We are cooperating in responding to the subpoena.

	We received a subpoena dated August 5, 2013 from the U.S. Department of Health and Human Services, Office of Inspector General. The subpoena requests documents relating to the marketing and promotion of Bystolic, Savella, and Namenda, including with respect to speaker programs for these products. In February 2014, the U.S. District Court for the Eastern District of Wisconsin unsealed a qui tam complaint with the caption “United States of America ex rel. Kurt Kroening et al. v. Forest Pharmaceuticals, Inc. and Forest Laboratories, Inc.” This complaint, which was filed in April 2012, asserts claims under the False Claims Act and contains allegations regarding off-label promotion of Bystolic and Savella and “kickbacks” provided to physicians to induce prescriptions of Bystolic, Savella, and Viibryd. In January 2014, the Eastern District of Wisconsin U.S. Attorney’s Office notified the court that it had not completed its investigation and therefore would not intervene in the action at that time (while reserving the right to intervene at a later date). We are continuing to cooperate with this investigation and to discuss these issues with the government. We intend to vigorously defend against the complaint. At this time, we are unable to estimate the reasonably possible loss or range of possible loss, but do not believe losses, if any, would have a material effect on the results of operations or financial position taken as a whole.

	In April 2014, the U.S. District Court for the District of Massachusetts unsealed a qui tam complaint with the caption “United States of America ex rel. Timothy Leysock v. Forest Laboratories, Inc. and Forest Pharmaceuticals, Inc.” This complaint, which was filed in July 2012, asserts claims under the False Claims Act and contains allegations regarding off-label promotion of Namenda. An Amended Complaint was filed in October 2012 and a Second Amended Complaint was filed in April 2014. On April 16, 2014, the District of Massachusetts U.S. Attorney’s Office notified the court that it was declining to intervene in the action. We intend to vigorously defend against the complaint. At this time, we are unable to estimate the reasonably possible loss or range of possible loss, but do not believe losses, if any, would have a material effect on the results of operations or financial position taken as a whole.

	On February 20, 2014, we received a letter from the U.S. Federal Trade Commission (FTC) indicating that the FTC is conducting a nonpublic investigation into our agreements with the ANDA filers for Bystolic. On May 2, 2014, we received a Civil Investigative Demand from the FTC requesting documents regarding such agreements. We are cooperating in responding to the investigation.

	On February 28, 2014, May 7, 2014, and May 29, 2014, we received Investigatory Subpoenas from the New York Attorney General’s Office primarily requesting (1) information regarding plans to discontinue the sale of Namenda tablets and (2) the Company’s agreements with ANDA filers for Bystolic. We are cooperating in responding to the subpoena.

	Product Liability Litigation

	We are defendants in approximately 200 product liability actions. Thirteen actions involve allegations that Celexa or Lexapro caused or contributed to individuals committing or attempting suicide, or caused a violent event. The MDL that was established for the federal suicidality-related litigation in the U.S. District Court for the Eastern District of Missouri has concluded and the remaining cases have been remanded to the federal district courts in which they were filed originally. Eight trials have been scheduled in these actions in 2014 and 2015. In February 2014, a state court action in Montgomery, Alabama involving a young woman who allegedly attempted suicide was dismissed with prejudice.

	Approximately one hundred and seventy-nine actions involve allegations that Celexa or Lexapro caused various birth defects. The majority of these actions have been consolidated in Cole County Circuit Court in Missouri. One action is set for trial in Cole County in September 2014. Approximately nineteen actions are pending in the U.S. District Court for the District of New Jersey. One action is pending in Orange County, California and is set for trial in January 2015.

	Approximately six actions involve allegations that Benicar, a treatment for hypertension that the Company co-promoted with Daiichi Sankyo between 2002 and 2008, caused certain gastrointestinal injuries. Under our Co-Promotion Agreement, Daiichi Sankyo is defending us in these lawsuits.

	Each product liability action seeks compensatory and punitive damages. We intend to continue to vigorously defend against these actions. For claims filed before April 1, 2014, we generally maintain $140 million of product liability coverage (annually, per “occurrence” on a claims-made basis, and in the aggregate). For these claims, the Company’s self-insured retention is $10 million per claim and $50 million in the aggregate. Claims filed after April 1, 2014 will be reported to the policy for the previous year. However, for these claims our self-insured retention is $20 million per claim and $60 million in the aggregate. Moreover, the Company is self-insuring a layer of coverage $10 million in excess of $55 million.

	Patent Litigation

	In September, October, and November 2013, and February 2014, we and Royalty Pharma Collection Trust (Royalty), our licensor for Savella, brought actions for infringement of U.S. Patent No. 6,602,911 (the ‘911 patent), U.S. Patent No. 7,888,342 (the ‘342 patent), and U.S. Patent No. 7,994,220 (the ‘220 patent) in the U.S. District Court for the District of Delaware against Amneal, Apotex, First Time US Generics, Glenmark, Hetero, Lupin, Mylan, Par, Ranbaxy, Sandoz, and related subsidiaries and affiliates thereof. These companies have notified us that they have filed ANDAs with the FDA seeking to obtain approval to market generic versions of Savella before these patents expire. (The ‘342 patent expires in November 2021, the ‘911 patent expires in January 2023, and the ‘220 patent expires in September 2029.) These lawsuits triggered an automatic stay of approval of the applicable ANDAs until July 14, 2016 (unless a court issues a decision adverse to us and Royalty Pharma sooner). On March 7, 2014, we and Royalty voluntarily dismissed, without prejudice, all claims against Sandoz. On March 20, 2014, the district court consolidated all of the remaining pending actions for all purposes and issued a scheduling order setting a trial date in January 2016. On May 12, 2014, the Company and Royalty entered into a settlement agreement with First Time US Generics. Under the terms of the settlement agreement, and subject to review of the settlement terms by the U.S. Federal Trade Commission, Forest will provide a license to First Time that will permit it to launch its generic version of SAVELLA as of the date that is the later of (a) six (6) calendar months prior to the expiration date of the last to expire of the ‘911 patent, the ‘342 patent, and the ‘220 patent, including any extensions and/or pediatric exclusivities; or (b) the date that First Time obtains final FDA approval of its ANDA, or earlier in certain circumstances.


	In January, February, and April 2014, we and Merz Pharma and Adamas Pharmaceuticals, our licensors for Namenda XR, brought actions for infringement of some or all of U.S. Patent No. 5,061,703 (the ‘703 patent), U.S. Patent No. 8,168,209 (the ‘209 patent), U.S. Patent No. 8,173,708 (the ‘708 patent), U.S. Patent No. 8,283,379 (the ‘379 patent), U.S. Patent No. 8,329,752 (the ‘752 patent), U.S. Patent No. 8,362,085 (the ‘085 patent), and U.S. Patent No. 8,598,233 (the ‘233 patent) in the U.S. District Court for the District of Delaware against Wockhardt, Teva, Sun, Apotex, Anchen, Zydus, Watson, Par, Mylan, Amneal, Amerigen, and related subsidiaries and affiliates thereof. These companies have notified us that they have filed ANDAs with the FDA seeking to obtain approval to market generic versions of Namenda XR before these certain patents expire. (The ‘703 patent expires in April 2015, the ‘009 patent expires in March 2029, and the ‘209, ‘708, ‘379, ‘752, ‘085, and ‘233 patents expire in November 2025.) These lawsuits triggered an automatic stay of approval of the applicable ANDAs that expires no earlier than June 2016 (unless a court issues a decision adverse to us, Merz, and Adamas sooner).

	In December 2013, we were named as a defendant in an action brought by Teva Pharmaceuticals USA, Inc. and Mayne Pharma International Pty Ltd. in the U.S. District Court for the District of Delaware under the caption “Teva Pharmaceuticals USA, Inc. and Mayne Pharma International Pty Ltd. v. Forest Laboratories, Inc.” The complaint alleges that we infringe U.S. Patent No. 6,194,000 by making, using, selling, offering to sell, and importing Namenda XR. The relief requested includes preliminary and permanent injunctive relief, and damages. We intend to continue to vigorously defend against this action. At this time, we are unable to estimate the reasonably possible loss or range of possible loss, but do not believe losses, if any, would have a material effect on the results of operations or financial position taken as a whole.

	In July 2013, our subsidiaries Aptalis Pharma US, Inc. and Aptalis Pharma Canada Inc. brought actions for infringement of U.S. Patent No. 8,217,083 (the ‘083 patent) and U.S. Patent No. 8,436,051 (the ‘051 patent) in the U.S. District Court for the District of New Jersey against Mylan and Sandoz. These companies have notified Aptalis that they have filed ANDAs with the FDA seeking to obtain approval to market generic versions of CANASA before these patents expire. Amended complaints were filed against these companies in November 2013 adding claims for infringement of U.S. Patent No. 7,854,384 (the ‘384 patent). The ‘083, ‘051, and ‘384 patents expire in June 2028. No trial date has been set.

	Stockholder Litigation

In February and March 2014, nine putative stockholder class actions were brought against us, our directors, Actavis plc, and certain of Actavis's affiliates. Four actions were filed in the Delaware Court of Chancery and have been consolidated under the caption "In re Forest Laboratories, Inc. Stockholders Litigation" (the Delaware Action). Five actions were filed in New York State Supreme Court and have been consolidated under the caption "Turberg v. Forest Laboratories, Inc. et al." (the New York Action). On April 4 and May 5, 2014, respectively, the Delaware and New York plaintiffs filed consolidated amended complaints in their respective jurisdictions. The amended complaints seek, among other remedies, to enjoin Actavis's proposed acquisition of Forest or damages in the event the transaction closes. The complaints generally allege, among other things, that the members of the Forest Board of Directors breached their fiduciary duties by agreeing to sell Forest for inadequate consideration and pursuant to an inadequate process, and that the disclosure document fails to disclose allegedly material information about the transaction. The complaints also allege that Actavis, and certain of its affiliates, aided and abetted these alleged breaches. On May 28, 2014, the defendants reached an agreement in principle with plaintiffs in the Delaware Action and the New York Action regarding a settlement of both Actions, and that agreement is reflected in a memorandum of understanding. In connection with the settlement contemplated by the memorandum of understanding, Forest agreed to make certain additional disclosures related to the proposed transaction with Actavis, which are contained in a Form 8-K filed May 28, 2014. The memorandum of understanding contemplates that the parties will enter into a stipulation of settlement. The stipulation of settlement will be subject to customary conditions, including court approval. In the event that the parties enter into a stipulation of settlement, a hearing will be scheduled at which the Delaware Court of Chancery will consider the fairness, reasonableness, and adequacy of the settlement. If the settlement is finally approved by the court, it will resolve and release all claims in all actions that were or could have been brought challenging any aspect of the proposed transaction, the merger agreement, and any disclosure made in connection therewith, including in the Definitive Joint Proxy Statement/Prospectus, pursuant to terms that will be disclosed to stockholders prior to final approval of the settlement. In addition, in connection with the settlement, the parties contemplate that the parties shall negotiate in good faith regarding the amount of attorneys' fees and expenses that shall be paid to plaintiffs' counsel in connection with the Actions. There can be no assurance that the parties will ultimately enter into a stipulation of settlement or that the Delaware Court of Chancery will approve the settlement even if the parties were to enter into such stipulation. In such event, the proposed settlement as contemplated by the memorandum of understanding may be terminated. At this time, we are unable to estimate the reasonably possible loss or range of possible loss, but do not believe losses, if any, would have a material effect on the results of operations or financial position taken as a whole.

In May 2014, three putative stockholder class actions were brought against us, Furiex Pharmaceuticals, Inc. (Furiex), and Furiex's board of directors. Two actions were brought in the Delaware Court of Chancery under the captions "Steven Kollman v. Furiex Pharmaceuticals, Inc. et al." and "Donald Powell v. Furiex Pharmaceuticals, Inc. et al." One action was brought in North Carolina state court under the caption "Walter Nakatsukasa v. Furiex Pharmaceuticals, Inc. et al." These actions seek to enjoin our proposed acquisition of Furiex and allege, among other things, that the members of the Furiex Board of Directors breached their fiduciary duties by agreeing to sell Furiex for inadequate consideration and pursuant to an inadequate process. These actions also allege that Forest aided and abetted these alleged breaches. We intend to continue to vigorously defend against these actions. At this time, we are unable to estimate the reasonably possible loss or range of possible loss, but do not believe losses, if any, would have a material effect on the results of operations or financial position taken as a whole.

Telephone Consumer Protection Act Litigation

In October 2012, we were named as a defendant, along with The Peer Group, Inc. (TPG), in a putative class action brought by the St. Louis Heart Center (SLHC) under the caption “St. Louis Heart Center, Inc. v. Forest Pharmaceuticals, Inc. and The Peer Group, Inc.” The action is now pending in the U.S. District Court for the Eastern District of Missouri. On May 17, 2013, SLHC filed a Fourth Amended Complaint, alleging that Forest and TPG violated the Telephone Consumer Protection Act of 1991, as amended by the Junk Fax Prevention Act of 2005, 47 U.S.C. § 227 (TCPA), on behalf of a proposed class that includes all persons who, from four years prior to the filing of the action, were sent telephone facsimile messages of material advertising the commercial availability of any property, goods, or services by or on behalf of defendants, which did not display an opt-out notice compliant with a certain regulation promulgated by the Federal Communications Commission (FCC). The Fourth Amended Complaint seeks $500 for each alleged violation of the TCPA, treble damages if the Court finds the violations to be willful, knowing or intentional, interest, and injunctive and other relief. On May 21, 2013, in Nack v. Walburg, a separate case in which we are not a party, the U.S. Court of Appeals for the Eighth Circuit ruled that the district court in that case lacked jurisdiction to determine the validity of this FCC regulation and that the defendant in that case could only challenge the validity of this regulation through an administrative petition submitted directly to the FCC, a decision that would then be appealable to the appropriate court of appeals. On June 27, 2013, we filed a Petition for Declaratory Ruling with the FCC requesting that the FCC find that (1) the faxes at issue in the action complied, or substantially complied with the FCC regulation, and thus did not violate it, or (2) the FCC regulation was not properly promulgated under the TCPA. On July 17, 2013, the district court granted our motion to stay the action pending the administrative proceeding initiated by our FCC Petition, including any appeal therefrom. On January 31, 2014, the FCC released a Public Notice in response to several related petitions, including ours. The comment and reply period for this Public Notice closed on February 14 and February 21, 2014, respectively. We intend to continue to vigorously defend against this action. At this time, we are unable to estimate the reasonably possible loss or range of possible loss, but do not believe losses, if any, would have a material effect on the results of operations or financial position taken as a whole.

Income_taxes

Income taxes	12 Months Ended
Income taxes	Mar. 31, 2014
Income taxes [Abstract]	'
Income taxes	'
	14. Income taxes:

	The components of income (loss) before income tax expense were:

	(In thousands)
	Years ended March 31,		2014				2013			2012
	U.S.		$	(242,233	)		$	(21,334	)	$	325,882
	Foreign			323,801				(23,524	)		911,806
	Income (loss) before income tax expense (benefit)		$	81,568			$	(44,858	)	$	1,237,688

	The provision for income taxes consists of the following:

	(In thousands)
	Years ended March 31,		2014				2013			2012
	Current:
	U.S. federal		$	9,616			$	20,134		$	222,012
	State and local			(5,087	)			(8,258	)		26,984
	Foreign			17,583				10,176			52,452
				22,112				22,052			301,448
	Deferred:
	U.S.			(96,236	)			(33,959	)		(41,970	)
	Foreign			(9,618	)			(848	)		(848	)
				(105,854	)			(34,807	)		(42,818	)
			$	(83,742	)		$	(12,755	)	$	258,630

	The reasons for the difference between the provision for income taxes and expected federal income taxes at statutory rates are as follows:

	Years ended March 31, (percentage of income		2014				2013			2012
	before income tax expense)		2014				2013			2012
	U.S. statutory rate			35	%			35	%		35	%
	Effect of foreign operations			(79.1	)			(88.8	)		(16.1	)
	Research credit			(16.0	)			46			(1.0	)
	State and local taxes, less federal tax benefit			7.7				(16.9	)		1.4
	Unrecognized tax benefit – audit settlement and statute expiration			(47.9	)			54.7			0
	Permanent differences and other items			(2.4	)			(1.6	)		1.6
				(102.7	)%			28.4	%		20.9	%

	The Company’s effective tax rate for fiscal years 2014, 2013 and 2012 is lower than the federal statutory rate principally as a result of the proportion of earnings generated in lower-taxed foreign jurisdictions as compared with the U.S. and the impact of Project Rejuvenate in the U.S. in 2014.

	Net deferred income taxes relate to the following timing differences:

	(In thousands)
	Years ended March 31,		2014				2013
	Inventory reserves		$	38,905			$	42,924
	Receivable allowances and other reserves			60,795				37,169
	Property, plant and equipment			(37,201	)			(24,302	)
	Intangible assets			(818,867	)			(255,260	)
	Carryforwards and credits			245,454				64,378
	Accrued liabilities			102,263				65,193
	Employee stock option tax benefits			36,436				41,726
	Other (includes reserve for legal contingencies)			24,226				21,169
				(347,989	)			(7,003	)
	Valuation allowance			(118,488	)			(9,787	)
	Deferred taxes, net		$	(466,477	)		$	(16,790	)

	The Company has federal, state and local, and foreign net operating loss carryforwards as well as excess charitable contribution carryovers, foreign tax credit carryovers and orphan drug credit carryovers which are available to reduce future U.S. federal and state taxable income, expiring at various times between 2014 and 2034. Valuation allowances have been established for a portion of deferred tax assets acquired as part of the Cerexa purchase and the Aptalis purchase as the Company determined that it was more likely than not that these benefits will not be realized.

	At March 31, 2014, U.S. taxes and foreign withholding have not been provided on approximately $7.8 billion of temporary differences primarily attributable to undistributed earnings of foreign subsidiaries as these undistributed earnings are indefinitely reinvested offshore. If, in the future, these earnings are repatriated to the U.S., or if such earnings are expected to be remitted in the foreseeable future, additional tax provisions would be required. Due to complexities in the tax laws and the assumptions that would have to be made, it is not practicable to estimate the amounts of income taxes that would have to be provided.

	The Company accrues liabilities for identified tax contingencies that result from positions that are being challenged or could be challenged by tax authorities. The Company believes that its accrual for tax liabilities is adequate for all open years, based on Management’s assessment of many factors, including its interpretations of the tax law and judgments about potential actions by tax authorities. However, it is possible that the ultimate resolution of any tax audit may be materially greater or lower than the amount accrued.

	The Company’s income tax returns for fiscal years prior to 2007 in most jurisdictions and prior to 2008 in Ireland are no longer subject to review as such fiscal years are generally closed. Tax authorities in various jurisdictions are in the process of reviewing the Company’s income tax returns for various post-2006 fiscal years, including the Internal Revenue Service, which is currently reviewing fiscal years 2007, 2008 and 2009. It is unlikely that the outcome will be determined within the next twelve months.

The Company has agreed with assessments from the New York State Department of Taxation for fiscal years 2003-2007 related to issues surrounding how the Company accounted for New York State corporation taxes on a consolidated basis. Such assessment resulted in additional New York State corporation tax within previously established tax reserves and did not have a material impact on the Company’s results of operations.

As of March 31, 2014 the Company’s consolidated Balance Sheet reflects unrecognized tax benefits (UTBs) of $437.0 million of which $406.4 million would impact the effective tax rate if recognized. A reconciliation of the beginning and ending amount of UTBs is as follows:

(In thousands)		2014				2013
Balance at beginning of period		$	492,088			$	498,292
Additions related to prior year positions			18,000				2,011
Reductions related to prior year positions			-				(1,630	)
Reduction related to audit settlement			(73,048	)			(7,806	)
Reduction related to statute expiration			(14,264	)			(11,500	)
Additions related to current year positions			9,694				12,721
Other			4,572				-
Balance as of March 31		$	437,042			$	492,088

The Company recorded interest related to UTBs in income tax expense and related liability accounts on the balance sheet. During the fiscal years ended March 31, 2014 and 2013, the Company recognized $16.5 million and $14.8 million of interest and penalties, respectively. Accrued interest related to UTBs totaled $51.7 million and $75.2 million as of March 31, 2014 and 2013, respectively.

It is anticipated that the amount of UTBs will not change significantly within the next 12 months.

Quarterly_financial_data_unaud

Quarterly financial data (unaudited)	12 Months Ended
Quarterly financial data (unaudited)	Mar. 31, 2014
Quarterly financial data (unaudited) [Abstract]	'
Quarterly financial data (unaudited)	'
	15. Quarterly financial data (unaudited):

	(In thousands)	Net sales		Gross profit		Net income (loss)			Diluted earnings (loss) per share
	2014
	First quarter	$	796,853	$	663,404	$	23,278		$	0.09
	Second quarter		811,429		683,736		69,987			0.26
	Third quarter		846,784		696,126		17,961			0.07
	Fourth quarter		1,048,280		842,991		54,084			0.2

	2013
	First quarter	$	751,766	$	649,378	$	55,285		$	0.21
	Second quarter		692,017		596,571		20,777			0.08
	Third quarter		677,967		562,970		(153,608	)		(0.58	)
	Fourth quarter		783,186		636,000		45,443			0.17

License_and_collaboration_agre

License and collaboration agreements

12 Months Ended

Mar. 31, 2014

License and collaboration agreements [Abstract]

License and collaboration agreements

16. License and collaboration agreements:

Saphris license

On November 29, 2013, the Company entered into an Asset Purchase Agreement (APA) with Merck to purchase exclusive rights in the U.S. for Saphris sublingual tablets, a treatment for adult patients with schizophrenia and, as monotherapy or adjunctive therapy, of manic or mixed episodes associated with bipolar I disorder. Pursuant to the APA, the Company paid Merck $155 million on January 10, 2014 upon close of the transaction and an additional $76 million in March 2014 for costs and expenses incurred in connection with post-marketing clinical trials conducted for Saphris during calendar 2013. The Company recorded an intangible asset of $231 million which will be amortized over the useful life of the product. The agreement also includes certain sales milestone payments to Merck upon the achievement of certain net sales thresholds.

In addition, the Company entered into a supply agreement pursuant to which Forest will purchase its commercial supply of the product from Merck at an agreed purchase price.

Fetzima approval

In July 2013, the Company received FDA approval for Fetzima^TM (levomilnacipran extended-release capsules), a once-daily serotonin and norepinephrine reuptake inhibitor for the treatment of Major Depressive Disorder in adults. The product was launched in December 2013 and recorded sales of $11.7 million in fiscal 2014. The Company licensed the rights to levomilnacipran in the U.S. and Canada from Pierre Fabre Laboratories, and was obligated to pay a milestone payment of $30 million upon FDA approval. Such milestone payment was capitalized as an intangible asset and is currently being amortized over the life of the patent for Fetzima.

Trevena

On May 9, 2013, the Company entered into a collaborative licensing option agreement with Trevena for the development of TRV027, a novel beta-arrestin biased ligand of the angiotensin II type 1 receptor for the treatment of acute decompensated heart failure. Pursuant to the agreement, the Company purchased $30 million of Trevena preferred stock in a round of private placement financing which is recorded in the non-current ‘Marketable securities and investments’ caption in the consolidated Balance Sheet. This investment was initially accounted for using the cost method. During the fourth quarter of fiscal 2014, Trevena filed an IPO, at which time the Company’s preferred stock was converted to common stock traded on the NASDAQ stock market. In conjunction with the IPO, the Company purchased an additional $3.0 million of common stock of Trevena. The investment was subsequently accounted for using the fair value method of accounting. At March 31, 2014, the fair value of the Trevena common stock held by the Company was $26.7 million.

Ironwood collaboration agreement

In September 2007, the Company entered into a collaboration agreement with Ironwood to jointly develop and commercialize Linzess® (linaclotide) for the treatment of irritable bowel syndrome with constipation (IBS-C) and chronic idiopathic constipation (CIC). Under the terms of the agreement, the Company shares equally with Ironwood all profits and losses from the development and commercialization of Linzess in the U.S. In addition, Forest obtained exclusive rights to the linaclotide license in Canada and Mexico, for which the Company will pay royalties to Ironwood based on net sales in those territories, subject to receiving regulatory approval.

The agreement included contingent milestone payments as well as a contingent equity investment based on the achievement of specific clinical and commercial milestones. As of March 31, 2014, payments totaling $230 million, relating to development and approval milestones, have been made. The Company may be obligated to pay up to an additional $100 million if certain sales milestones are achieved.

Linzess received FDA approval as a once-daily treatment for adult men and women suffering from IBS-C and CIC in August 2012. For the year ended March 31, 2014, Linzess sales in the U.S. totaled $175.1 million.

Based on the nature of the arrangement (including its contractual terms), the nature of the payments and applicable guidance, the Company records receipts from and payments to Ironwood in two pools: the Development pool which consists of R&D expenses, and the Commercialization pool, which consists of revenue, cost of sales and SG&A expenses. The net payment to or receipt from Ironwood for the Development pool is recorded in R&D expense and the net payment to or receipt from Ironwood for the Commercialization pool is recorded in SG&A expense.

The following illustrates activity related to the Ironwood collaboration agreement for the periods presented:

(In thousands)

Year ended March 31,

2014

2013

2012

Revenue

Net Sales of Linzess

175,063

23,728

Cost of sales

Cost of sales of Linzess

7,448

1,010

SG&A

Payment to/ (receipt from) Ironwood for the Commercialization pool

(5,371

)

(39,244

)

(2,425

)

R&D

Payment to/ (receipt from) Ironwood for the Development pool

1,510

(4,368

)

2,884

)

In September 2012, the Company entered into an agreement with Almirall, S.A. whereby we sublicensed the rights to commercialize linaclotide in Mexico to Almirall. Almirall obtained regulatory approval for linaclotide in Mexico in February 2014 and we recorded income of $2.5 million for a milestone payment from Almirall due upon approval. Almirall is expected to launch the product in Mexico in mid-2014. We will receive royalties based on sales of the product in Mexico, a portion of which will be due to Ironwood.

moksha8

On October 22, 2012, the Company announced an agreement with moksha8, a privately-held pharmaceutical company which markets products in Latin America. The agreement includes an exclusive license from Forest to moksha8 to commercialize Viibryd, and potentially other Forest products, in Latin America.

Under the arrangement, the Company has provided $101.9 million of debt financing to moksha8, of which $19.2 million was funded during the fiscal 2014. Such debt financing has a term of seven years from the date of initial funding and is collateralized by the assets of moksha8. The Company has recorded a loan receivable as a long term asset in the Company’s consolidated Balance Sheet which is included in the ‘Other assets’ caption.

In January 2014, the Company and moksha8 agreed to amend the terms of the agreement, including to terminate (i) the agreements containing Forest’s obligations to provide additional funding to moksha8 and (ii) Forest’s option to acquire moksha8, as well as the shareholders of moksha8’s option to put to Forest all interests of moksha8. moksha8 will, subject to certain conditions, retain the exclusive license to commercialize Viibryd.

Business_combinations

Business combinations	12 Months Ended
Business combinations	Mar. 31, 2014
Business combinations [Abstract]	'
Business combinations	'
	17. Business combinations:

	Aptalis

	On January 31, 2014, the Company acquired Aptalis Holdings, Inc. (Aptalis); a privately held U.S. based pharmaceutical company, for an aggregate purchase price equal to $2.9 billion minus Aptalis’ existing indebtedness and related fees and costs, minus certain of Aptalis’ expenses, plus the aggregate exercise price applicable to Aptalis’ outstanding options. The Company funded the acquisition through $1.2 billion of cash on hand, including $650.0 of cash from a foreign subsidiary, and the proceeds from the issuance of aggregate principal of $1.8 billion of Senior Notes issued on January 31, 2014.

	Aptalis is an international, specialty pharmaceutical company that focuses on developing, manufacturing, licensing and marketing therapies for certain cystic fibrosis (CF) and gastrointestinal-related disorders. Aptalis’ business focuses on therapeutic areas that are currently underserved by large pharmaceutical companies and are characterized by products used for chronic conditions. Aptalis has manufacturing and commercial operations in the U.S., the European Union and Canada, and its principal products include Zenpep® (pancrelipase), Canasa® (mesalamine, USP), Carafate® (sucralfate tablets and suspensions), Pylera®(bismuth subcitrate potassium; metronidazole; tetracycline HCl) and Salofalk® (mesalamine).

	As part of the acquisition, the Company acquired Aptalis’ Pharmaceutical Technologies (PT) business. The PT business consists of a portfolio of proprietary technology platforms that have produced over 35 approved products in over 35 countries, supported the Aptalis specialty pharmaceutical business and provided an opportunity to develop innovative internal products and the flexibility to offer third-parties co-development programs, product out-licensing and manufacturing programs.

	With this acquisition, the Company gained numerous strategic benefits, including an increased presence both domestically and internationally, expansion of its key therapeutic areas and customer base, and an opportunity to realize operating efficiencies.

	The following table summarizes the fair values of the assets acquired, including goodwill and intangible assets, and liabilities assumed as of the acquisition date. These amounts are provisional and subject to change:

	(In thousands)
	Assets acquired/liabilities assumed	Fair value at acquisition date
	Accounts receivable, net	$	122,077
	Inventories, net		141,750
	Other current assets		27,971
	Property, plant and equipment, net		103,762
	Intangible assets, net		2,928,800
	Other assets		2,236
	Accounts payable and accrued liabilities		(153,575	)
	Other current liabilities		(17,936	)
	Long term deferred tax liabilities		(548,768	)
	Other long term liabilities		(41,734	)
	Total identifiable net assets acquired		2,564,583
	Goodwill		335,417
	Total	$	2,900,000

	Cash on hand at acquisition		112,286
	Total cash transferred at acquisition	$	3,012,286

	Goodwill is calculated as the excess of the consideration transferred over the total identifiable net assets recognized and represents the expected synergies of the purchased business, the assembled workforce, the broadening of the Company’s gastrointestinal therapeutic area and expansion into the CF market.

	Included in the assets acquired were definite lived intangible assets of $2.9 billion and indefinite lived intangible assets of $16.6 million which consisted of In Process Research & Development (IPR&D) assets.

	Upon consummation of the Aptalis acquisition, Forest performed a detailed fair value analysis of each of the definite lived and indefinite lived intangibles to determine fair value using the income approach. Significant assumptions inherent in the development of those asset valuations include, but are not limited to the estimated net cash flows, the appropriate discount rate, the assessment of each asset’s life cycle and competitive trends impacting the asset and each cash flow stream.

	A key variable in determining the fair value of IPR&D includes the application of probability factors related to the likelihood of success of the respective products reaching each remaining stage of clinical and regulatory development, including market commercialization. Acquired IPR&D assets are classified as indefinite-lived assets until the successful completion or abandonment of the associated research and development efforts. These assets will not be amortized into earnings and, instead, these assets will be subject to periodic impairment analysis until the completion of the development process and the determination of the useful life of the asset is made. At such time, the asset would then be considered a definite lived intangible asset and amortized accordingly. If an IPR&D project were not successfully developed, an impairment charge may result.

	Actual and Pro Forma Impact

	The Company’s consolidated Financial Statements include Aptalis’ results of operations from the date of acquisition on January 31, 2014 through the fiscal year ended March 31, 2014. Net sales, net loss and net loss per share attributable to Aptalis during this period and included in the Company’s consolidated Financial Statements for the period ended March 31, 2014 totaled $108.4 million, ($24.0) million and ($0.09) respectively.

	The following unaudited pro forma information gives effect to the Company’s acquisition of Aptalis as if the acquisition had occurred on April 1, 2012 and had been included in the Company’s consolidated results of operations for the years ended March 31, 2014 and March 31, 2013:

	(In thousands, except per share data)
	Years ended March 31,	2014			2013
	Net sales	$	4,079,156		$	3,551,193
	Net loss		(69,023	)		(148,355	)
	Basic loss per share		(0.26	)		(0.56	)
	Diluted net loss per share		(0.26	)		(0.56	)

	The historical consolidated financial information of Forest has been adjusted to give effect to events that are (1) directly attributable to the transactions, (2) factually supportable and (3) with respect to the statements of operations, expected to have a continuing impact on the combined results, including the issuance of $1.2 billion of Senior Notes in December 2013 and the issuance of $1.8 billion of senior unsecured notes in January 2014. The unaudited pro forma information does not and is not intended to project the future financial position or operating results of the combined company and do not reflect any acquisition-related restructuring charges and integration charges expected to be incurred by Forest in connection with the acquisition.

	Clinical Data

	On April 13, 2011, the Company acquired Clinical Data, a specialty pharmaceutical company, for $30 per share, plus contingent consideration, per a Contingent Value Rights agreement (CVR) of up to $6 per share if certain milestones connected to sales of Viibryd, one of the acquired products, are achieved. The acquisition was consummated by a wholly-owned subsidiary of the Company through a tender offer and merger, pursuant to which the Company acquired all of the outstanding shares of common stock of Clinical Data and all related securities. The Company fully integrated the operations of Clinical Data into its existing structure. The aggregate consideration paid was approximately $1.3 billion, which the Company financed with existing cash.

	The approximate range of undiscounted amounts the Company may be required to pay under the CVR is between zero and $275 million. The fair value of the contingent consideration recognized at the acquisition date was approximately $25 million which the Company determined based on a probability-weighted discounted cash flow analysis. During the fourth quarter of fiscal 2013, the Company determined the fair value of the contingent consideration to be zero, which resulted in an adjustment of $25.2 million which is included in SG&A expense.

Restructuring_initiative

Restructuring initiative	12 Months Ended
	Mar. 31, 2014
Restructuring initiative [Abstract]	'
Restructuring initiative	'
	18. Restructuring initiative:

	During the third quarter of fiscal 2014, the Company announced Project Rejuvenate, a $500 million cost savings initiative with a goal of streamlining operations and reducing the Company’s operating cost base. Project Rejuvenate is focused on three areas: flattening and broadening the organization to reduce layers and increase spans of control, increase the Company’s productivity and profitability by decreasing costs and streamlining work to reduce low value activities.

	The Company expects annualized savings of approximately $270 million associated with the streamlining and realigning the R&D organization, $150 million in savings associated with the reduction of marketing expenses and $80 million in cost savings from a reduction in general and administrative expenses. Forest currently estimates that approximately $110 million of the cost savings will result from a reduction in headcount. The Company expects to achieve 65%-75% of the cost savings from Project Rejuvenate by the end of fiscal 2015 and the remainder by the end of fiscal 2016.

	The Company expects the total cost to implement Project Rejuvenate to be in the range of $150 million to $200 million. For the year ended March 31, 2014, Forest recorded $154.1 million in pre-tax restructuring expenses, which was comprised of $74.9 million for the write down to fair value of certain facilities deemed held for sale as a result of Project Rejuvenate, $59.3 million for employee termination benefits, and $20.0 million for consulting and other fees. These expenses were recorded in R&D expense and SG&A expense, as appropriate.

	The liability balance for the cost savings initiative as of March 31, 2014 is as follows:

	(In thousands)
		Post-Employment			Consulting			Total
		Benefits			Fees & Other
	Beginning Balance as of October 1, 2013	$	-		$	-		$	-
	Expenses		59,273			19,953			79,226
	Cash Payments		(2,384	)		(10,034	)		(12,418	)
	Balance as of March 31, 2014	$	56,889		$	9,919		$	66,808

	In addition to Project Rejuvenate, the Company recognized $16.5 million of post-employment benefits related to the Aptalis integration during the fiscal fourth quarter. As of March 31, 2014, the Company has a liability balance of $7.3 million related to employee termination costs in connection with the Aptalis integration.

Actavis_transaction

Actavis transaction	12 Months Ended
Actavis transaction	Mar. 31, 2014
Actavis transaction [Abstract]	'
Actavis transaction	'
	19. Actavis transaction:

	On February 17, 2014, the Company and Actavis plc (Actavis), a company incorporated under the laws of Ireland, entered into an Agreement and Plan of Merger (the Merger), dated as of February 17, 2014 (the Merger Agreement), pursuant to which Actavis has agreed, subject to the terms and conditions thereof, to acquire the Company. As a result of the Merger, the Company will become a wholly owned subsidiary of Actavis. The merger is expected to close during the second half of calendar 2014.

	The Merger Agreement provides that, upon completion of the Merger, each share of the Company’s common stock issued and outstanding immediately prior to the Merger (other than dissenting shares) will be converted into the right to receive, at the election of the holder thereof: (1) a combination of $26.04 in cash plus 0.3306 Actavis ordinary shares (the Mixed Election Consideration); (2) $86.81 in cash (the Cash Election Consideration); or (3) 0.4723 Actavis ordinary shares (the Stock Election Consideration). Shares of Company common stock with respect to which no election is made will receive the Mixed Election Consideration. Stockholders who make the Cash Election or the Stock Election will be subject to proration to ensure that the total amount of cash paid and the total number of Actavis shares issued to Forest shareholders as a whole are equal to the total amount of cash and number of Actavis shares that would have been paid and issued if all Forest shareholders received the Mixed Election consideration.

	Each of Actavis’ and Forest’s obligation to consummate the Merger is subject to a number of conditions, including, among others, the following: (i) approval of Actavis shareholders of the issuance of Actavis shares, (ii) approval of Forest stockholders of the adoption of the Merger Agreement, (iii) expiration of the waiting period (or extension thereof) under the Hart-Scott-Rodino Antitrust Improvement Act of 1976 and receipt of any approvals required thereunder and under applicable foreign antitrust laws having been obtained, (iv) the shares of Actavis to be issued in the Merger being approved for listing on the New York Stock Exchange, (v) the representations and warranties of the other party being true and correct, subject to the materiality standards contained in the Merger Agreement, (vi) absence of specified adverse laws or orders, (vii) an Irish prospectus with respect to the Actavis shares to be issued (if required by Irish law) in the Merger being approved by the Central Bank of Ireland and made available to the public in accordance with Irish prospectus law, (viii) material compliance by the other party with its covenants and (ix) no material adverse effect having occurred with respect to the other party since the signing of the Merger Agreement.

	The Merger Agreement contains certain customary termination rights, including, among others, (a) the right of either Actavis or Forest to terminate the Merger Agreement if Forest’s stockholders fail to adopt the Merger Agreement or if Actavis’ shareholders fail to approve the issuance of Actavis shares, (b) the right of either Actavis or Forest to terminate the Merger Agreement if the board of directors of the other party changes its recommendation with respect to the transaction, (c) the right of either Actavis or Forest to terminate the Merger Agreement if the Merger has not occurred by six months after the date of the Merger Agreement (the Outside Date), subject to certain conditions, provided that the Outside Date may be extended by up to an additional four months in certain circumstances, and (d) the right of either Actavis or Forest to terminate the Merger Agreement due to a material breach by the other party of any of its representations, warranties or covenants which would result in the closing conditions not being satisfied, subject to certain conditions.

Subsequent_events

Subsequent events	12 Months Ended
Subsequent events	Mar. 31, 2014
Subsequent events [Abstract]	'
Subsequent events	'
	20. Subsequent events:

	On April 28, 2014, the Company entered into a definitive agreement to acquire Furiex Pharmaceuticals, Inc. (Furiex) for $1.1 billion in cash and up to $30 per share in contingent value rights. Through the acquisition of Furiex, a drug development collaboration company based in the U.S., the Company will have access to Furiex’s leading drug candidate, eluxadoline, a locally-acting mu opioid receptor agonist and a delta opioid receptor antagonist for treating symptoms of diarrhea-predominant irritable bowel syndrome (IBS-d). Eluxadoline and other products acquired will compliment and build on the Company’s GI therapeutic business.

SCHEDULE_II_VALUATION_AND_QUAL

SCHEDULE II - VALUATION AND QUALIFYING ACCOUNTS	12 Months Ended
SCHEDULE II - VALUATION AND QUALIFYING ACCOUNTS	Mar. 31, 2014
SCHEDULE II - VALUATION AND QUALIFYING ACCOUNTS [Abstract]	'
SCHEDULE II - VALUATION AND QUALIFYING ACCOUNTS	'

	SCHEDULE II

	FOREST LABORATORIES, INC. AND SUBSIDIARIES
	VALUATION AND QUALIFYING ACCOUNTS
	(In thousands)

	Description	Balance at		Balances		Additions		Deductions			Balance
		beginning		acquired (i)							at end of
		of period									period

	Year ended March 31, 2014:

	Allowance for doubtful accounts	$	2,003	$	-	$	30	$	2	(ii)	$	2,031
	Allowance for cash discounts		9,241		1,461		93,227		92,302	(iii)		11,627
	Inventory reserve		18,441		-		17,002		5,967	(ii)		29,476

	Year ended March 31, 2013:

	Allowance for doubtful accounts	$	2,290	$	-	$	27	$	314	(ii)	$	2,003
	Allowance for cash discounts		8,156		-		73,430		72,345	(iii)		9,241
	Inventory reserve		23,785		-		1,000		6,344	(ii)		18,441

	Year ended March 31, 2012:

	Allowance for doubtful accounts	$	2,298	$	-	$	49	$	57	(ii)	$	2,290
	Allowance for cash discounts		13,985		-		107,892		113,721	(iii)		8,156
	Inventory reserve		16,743		-		8,042		1,000	(ii)		23,785

	(i) Represents balance acquired as part of Aptalis acquisition.
	(ii) Represents actual amounts written off.
	(iii) Represents cash discounts given.

Summary_of_significant_account1

Summary of significant accounting policies (Policies)

12 Months Ended

Mar. 31, 2014

Summary of significant accounting policies [Abstract]

Basis of presentation

Basis of presentation: The Consolidated Financial Statements are prepared in conformity with accounting principles generally accepted in the United States (GAAP) and include the accounts of Forest Laboratories, Inc. and its subsidiaries (“Forest,” “we,” “us,” or “the Company”) all of which are wholly-owned. All intercompany accounts and transactions have been eliminated.

Estimates and assumptions

Estimates and assumptions: GAAP requires the Company to make estimates and assumptions that affect the reported amounts of assets and liabilities as of the end of each period and of revenues and expenses during the reporting periods. Situations where estimates are required to be made include, but are not limited to, accounting for business combinations, sales allowances, returns, rebates and other pricing adjustments, depreciation, amortization, tax assets and liabilities, restructuring reserves, and certain contingencies. Actual results may vary from estimates. The Company reviews all significant estimates affecting the financial statements on a recurring basis and records the effect of any adjustments when necessary.

Reclassifications

Reclassifications: Certain amounts as previously reported have been reclassified to conform to current year classifications.

In the third quarter of fiscal 2014, the Company modified the presentation of its Consolidated Statements of Operations effective for all periods presented, whereby Interest income, interest expense and other miscellaneous income/expense is presented in the ‘Interest and other income (expense)’ caption below Operating income (loss). The modified presentation is consistent with industry practice and conforms with the requirements of Regulation S-X 5.03. There were no changes in the Company’s accounting policies, methodology for estimates or the activity included in the respective captions in the Consolidated Statements of Operations.

Foreign currency translation

Foreign currency translation: The statements of operations of the Company’s foreign subsidiaries are translated into U.S. dollars using average exchange rates for the applicable period. Gains and losses arising from foreign currency transactions are included in the statements of operations. The assets and liabilities of the Company’s foreign subsidiaries are translated into U.S. dollars using exchange rates at the end of the applicable period. The resulting translation adjustments arising from changes in the exchange rates are recorded in Accumulated other comprehensive income (loss) (AOCI).

Cash equivalents

Cash equivalents: Cash equivalents consist of highly liquid investments purchased with maturities within three months of the purchase date which are readily convertible into cash.

Inventories

Inventories: Inventories are stated at the lower of cost or market, with cost determined on a first-in, first-out basis.

Pre-launch inventories

Pre-launch inventories: The Company may accumulate commercial quantities of certain of its product candidates prior to the date it anticipates that such products will receive final U.S. Food and Drug Administration (FDA) approval. The accumulation of such pre-launch inventories involves the risk that such products may not be approved for marketing by the FDA on a timely basis, or ever. This risk notwithstanding, the Company may accumulate pre-launch inventories of certain products when such action is appropriate in relation to the commercial value of the product launch opportunity. In accordance with Company policy, this pre-launch inventory is expensed. At March 31, 2014 and 2013, the Company had no pre-launch inventories.

Marketable securities

Marketable securities: Marketable securities, which are all classified as available-for-sale, are stated at fair value based on quoted market prices in accordance with Accounting Standards Codification (ASC) 320, “Investments - Debt and Equity Securities”, and consist of high quality investments.

Accounts receivable and credit policies

Accounts receivable and credit policies: The carrying amount of accounts receivable is reduced to fair value by recording a valuation allowance that reflects management's best estimate of the amounts that will not be collected. In addition to reviewing delinquent accounts receivable, management considers many factors in estimating its general allowance, including historical data, experience, customer types, creditworthiness and economic trends. From time to time, management may adjust its assumptions for anticipated changes in any of those or other factors expected to affect collectability.

Long-term receivables

Long-term receivables: Long-term receivables consist of balances that are due to the Company in a period greater than one year from the balance sheet date. As of March 31, 2014, Long-term receivables include note receivables of $101.9 million associated with the moksha8 agreement. Refer to Note 16 License and collaboration agreements for additional information.

Property, plant and equipment and depreciation

Property, plant and equipment and depreciation (estimated useful lives are stated in years): Property, plant and equipment (PP&E) are stated at cost. Depreciation is recorded using the straight-line method over the estimated useful life for each asset. As of March 31, 2014 and 2013, the Company’s PP&E balance and useful lives by category was as follows:

(In thousands)

Years ended March 31,

2014

2013

Depreciation period in years

Land

26,827

32,740

Buildings and improvements

183,427

294,370

Oct-50

Machinery, equipment and other

427,584

373,385

10-Mar

Construction in progress

62,412

39,207

Property, plant and equipment

700,250

739,702

Less: accumulated depreciation

328,435

362,742

Property, plant and equipment, net

371,815

376,960

Leasehold improvements are depreciated over the lesser of the useful life of the assets or the lease term. Included in property, plant and equipment at March 31, 2014 and 2013 is construction in progress of $62.4 million and $39.2 million, respectively, for facility expansion at one specific location necessary to support the Company’s current and future operations as well as upgrades to our data processing equipment. Projects currently in-process or under evaluation are estimated to cost approximately $67.7 million to complete. For construction in progress, depreciation commences once the asset is placed into service.

Goodwill

Goodwill: Goodwill represents the excess of the fair value of the consideration transferred for an acquired business over the fair value of the identifiable net assets. The Company operates in only one segment. The Company completed its annual impairment assessments for the years ended March 31, 2014 and 2013 and concluded that goodwill was not impaired.

Revenue recognition

Revenue recognition: Revenues are recorded in the period the merchandise is shipped. As is typical in the pharmaceutical industry, gross product sales are subject to a variety of deductions, primarily representing rebates and discounts to government agencies, wholesalers and managed care organizations. These deductions represent estimates of the related liabilities as judgment is required when estimating the impact of these sales deductions on gross sales for a reporting period. Historically, our adjustments for actual settlements have not been material. If estimates are not representative of actual future settlement, results could be materially affected.

Provisions for estimated sales allowances, returns, rebates and other pricing adjustments are accrued at the time revenues are recognized as a direct reduction of such revenue. The accruals are estimated based on available information, including third party data regarding the portion of sales on which rebates and discounts can be earned, adjusted as appropriate for specific known events and the prevailing contractual discount rate. Provisions are reflected either as a direct reduction to accounts receivable or, to the extent that they are due to entities other than customers, as accrued expenses. Adjustments to estimates are recorded when Management becomes aware of a change of circumstances or when customer credits are issued or payments are made to third parties. There were no material adjustments to these estimates in the periods presented.

Deductions for chargebacks (primarily discounts to group purchasing organizations and federal government agencies) closely approximate actual deductions as these deductions are settled generally within 2-3 weeks of incurring the liability.

The sensitivity of estimates can vary by program and type of customer. However, estimates associated with Medicaid and contract rebates are most at risk for adjustment because of the extensive time delay between the recording of the accrual and its ultimate settlement, generally an interval that can range up to one year. Because of this time lag, in any given quarter, adjustments to actuals may incorporate revisions of prior quarters.

Sales incentives are generally given in connection with new product launches. These sales incentives are recorded as a reduction of revenues and are based on terms fixed at the time goods are shipped. New product launches may result in expected temporary increases in wholesaler inventories, which are closely monitored and historically have not resulted in increased product returns.

Shipping and handling costs

Shipping and handling costs: Presently, the Company does not charge its customers for any freight costs for domestic shipments in the ordinary course of business. The amounts of such costs are included in Selling, general and administrative (SG&A) expense and are not material.

Research and development

Research and development: Expenditures for Research and development (R&D), including upfront licensing fees and milestone payments (license payments) associated with developmental products that have not yet been approved by the FDA, are charged to R&D expense as incurred. License payments due to third parties upon, or subsequent to, FDA approval are recorded as intangible assets and classified as License agreements, product rights and other intangibles, net.

Savings and profit sharing plans

Savings and profit sharing plans: Substantially all non-bargaining unit employees of the Company's domestic subsidiaries may participate in the savings and profit sharing plans after becoming eligible for the respective plan (as defined in each of the plans). In the Savings Plan, participants contribute a portion of their qualifying compensation each pay period, up to the allowable limit, and the Company provides a matching contribution as defined by the plan. For the Profit Sharing Plan, the Company makes contributions on an annual basis, which are allocated to participants as defined by the plan. All contributions made to the Profit Sharing Plan are at the discretion of the Company. Savings and profit sharing contributions amounted to approximately $43.5 million, $45.9 million and $43.4 million for fiscal years 2014, 2013 and 2012, respectively.

Earnings (loss) per share

Earnings (loss) per share: Basic earnings per share is computed by dividing net income available to common stockholders by the weighted average number of common shares outstanding for the period. Diluted earnings per share reflects, in periods in which they have a dilutive effect, the effect of common shares issuable upon the exercise of outstanding stock options and vesting of restricted stock. The weighted average number of diluted common shares outstanding is reduced by the treasury stock method which, in accordance with ASC 718 “Compensation – Stock Compensation”, takes into consideration the compensation cost attributable to future services not yet recognized.

Accumulated other comprehensive income (loss)

Accumulated other comprehensive income (loss): Other comprehensive income (loss) refers to revenues, expenses, gains and losses which are excluded from net income under GAAP. These amounts are recorded as an adjustment to AOCI, which is reflected as a separate component of equity. AOCI comprises the cumulative effects, net of taxes, of foreign currency translation, pension liability adjustments and unrealized gains (losses) on securities, and amounted to approximately $12.4 million, $(2.1) million and $1.8 million, respectively, at March 31, 2014 and $1.4 million, $(8.8) million and $17.5 million, respectively, at March 31, 2013.

Income taxes

Income taxes: The Company accounts for income taxes using the liability method. Under the liability method, deferred income taxes are provided on the differences in bases of assets and liabilities between financial reporting and tax returns using enacted tax rates.

Uncertain tax positions

Uncertain tax positions: The Company recognizes the tax benefit from an uncertain tax position only if it is more likely than not that the tax position will be sustained on examination by the taxing authorities, based on the technical merits of the position. The tax benefits recognized in the financial statements from such a position are measured based on the largest benefit that has a greater than 50 percent likelihood of being realized upon ultimate resolution.

Long-lived assets, other than goodwill

Long-lived assets, other than goodwill: Long-lived assets, such as intangible assets and property, plant and equipment, are evaluated for impairment periodically or when events or changes in circumstances indicate that the carrying amount of the assets may not be recoverable through the estimated undiscounted future cash flows from the use of these assets. When any such impairment exists, a charge is recorded in the Statement of Operations in that period, to adjust the carrying value of the related asset. For the fiscal years ended March 31, 2014, 2013 and 2012, there were no such impairment charges recorded.

Stock-based compensation

Stock-based compensation: The Company’s Compensation Committee and the Board of Directors awards stock options, restricted stock, and performance-based restricted stock units (PSUs) to employees and non-employee directors. The fair value of stock options is calculated using the Black-Scholes valuation model, restricted stock is accounted for at fair value based upon the stock price on the date of grant and PSUs, which contain market conditions, are valued using a Monte Carlo simulation model. These compensation costs are amortized on a straight-line basis (net of forfeitures) over the requisite service period.

Compensation expense of $69.1 million ($46.1 million net of tax), $64.7 million ($45.7 million net of tax), and $59.3 million ($44.3 million net of tax) was recorded for the fiscal years ended March 31, 2014, 2013 and 2012, respectively. This expense was charged to cost of sales, SG&A expense and R&D expense, as appropriate. Total compensation cost related to non-vested stock based awards not yet recognized as of March 31, 2014 was $125.0 million pre-tax and the weighted average period over which the cost is expected to be recognized is approximately 2.3 years.

The following weighted average assumptions were used in determining the fair values of stock options using the Black-Scholes model:

Year ended March 31,

2014

2013

2012

Expected dividend yield

Expected stock price volatility

23.26

25.1

27.49

Risk-free interest rate

1.5

1.2

1.4

Expected life of options (years)

The Company has never declared a cash dividend. The expected stock price volatility is based on implied volatilities from traded options on the Company’s stock as well as historical volatility. The risk-free interest rate is based on the U.S. Treasury yield curve in effect at the time of grant in conjunction with the expected life of options. The expected life is based upon historical data and represents the period of time that granted options are expected to be outstanding.

Collaboration arrangements

Collaboration arrangements: The Company accounts for collaboration arrangements in accordance with ASC 808 - “Collaborative Agreements” pursuant to which payments to and receipts from our collaboration partners are presented in our Consolidated Statements of Operations based on the nature of the arrangement (including its contractual terms), the nature of the payments and applicable guidance.

Business combinations

Business combinations: The Company accounts for business combinations under the acquisition method of accounting, which requires the assets acquired and liabilities assumed to be recorded at their respective fair values as of the acquisition date in the Company’s Consolidated Financial Statements. The determination of estimated fair value may require management to make significant estimates and assumptions. The purchase price is the fair value of the total consideration conveyed to the seller and the excess of the purchase price over the fair value of the acquired net assets, where applicable, is recorded as goodwill. The results of operations of an acquired business are included in our Consolidated Financial Statements from the date of acquisition. Costs associated with the acquisition of a business are expensed in the period incurred.

Debt

Debt: The Company’s carrying value of debt is principal, net of unamortized discount. Any costs associated with the issuance of debt is capitalized and amortized over the term of the debt.

Recent accounting standards

Recent accounting standards: In April 2014, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) 2014-08, Presentation of Financial Statements (Topic 205) and Property, Plant, and Equipment (Topic 360): Reporting Discontinued Operations and Disclosures of Disposals of Components of an Entity. The amendments in this update will change the requirements for reporting discontinued operations. A discontinued operation may include a component of an entity, a group of components of an entity, or a business or nonprofit activity. A disposal of a component or a group of components is required to be reported in discontinued operations if the disposal represents a strategic shift that has (or will have) a major effect on an entity’s operations and financial results. This standard would become effective for the Company on April 1, 2015 and the adoption of this standard is not expected to have a significant impact on the Company’s financial statements.

Summary_of_significant_account2

Summary of significant accounting policies (Tables)	12 Months Ended
Summary of significant accounting policies (Tables)	Mar. 31, 2014
Summary of significant accounting policies [Abstract]	'
Property, plant and equipment	'
	As of March 31, 2014 and 2013, the Company’s PP&E balance and useful lives by category was as follows:

	(In thousands)

	Years ended March 31,	2014			2013			Depreciation period in years
	Land	$	26,827		$	32,740
	Buildings and improvements		183,427			294,370			Oct-50
	Machinery, equipment and other		427,584			373,385			10-Mar
	Construction in progress		62,412			39,207
	Property, plant and equipment		700,250			739,702
	Less: accumulated depreciation		328,435			362,742
	Property, plant and equipment, net	$	371,815		$	376,960

Summary of weighted average assumptions used in determining fair value of stock options	'
	The following weighted average assumptions were used in determining the fair values of stock options using the Black-Scholes model:

	Year ended March 31,	2014			2013			2012
	Expected dividend yield		0	%		0	%		0	%
	Expected stock price volatility		23.26	%		25.1	%		27.49	%
	Risk-free interest rate		1.5	%		1.2	%		1.4	%
	Expected life of options (years)		7			7			7

Net_income_loss_per_share_Tabl

Net income (loss) per share (Tables)	12 Months Ended
Net income (loss) per share (Tables)	Mar. 31, 2014
Net income (loss) per share [Abstract]	'
Reconciliation of shares used in calculating basic and diluted net income per share	'
	A reconciliation of shares used in calculating basic and diluted net income per share follows:

	(In thousands)
	Years ended March 31,	2014		2013		2012
	Basic		269,129		266,807		273,561
	Incremental shares attributable to share based compensation plans		3,818		-		455
	Diluted		272,947		266,807		274,016

Business_operations_Tables

Business operations (Tables)	12 Months Ended
Business operations (Tables)	Mar. 31, 2014
Business operations [Abstract]	'
Net sales and long lived fixed assets by country	'
	The net sales and long-lived assets for the years ended March 31, 2014, 2013 and 2012, are from the Company’s or one of its subsidiaries’ country of origin, as follows:

	(In thousands)	2014						2013					2012
		Net sales			Long-lived assets			Net sales			Long-lived assets		Net sales		Long-lived assets
	U.S.	$	3,329,367		$	707,784		$	2,769,541		$	432,085	$	4,261,976	$	386,427
	Ireland		74,360			3,949,311			60,014			2,759,428		61,747		2,759,069
	United Kingdom		76,043			23,608			75,381			26,177		68,825		31,663
	Canada		5,725			1,792,332			-			-		-		-
	Italy		8,166			78,356			-			-		-		-
	Other		9,685			29,871			-			-		-		-
		$	3,503,346		$	6,581,262		$	2,904,936		$	3,217,690	$	4,392,548	$	3,177,159
Net sales by therapeutic class	'
	Net sales by therapeutic class are as follows:

	(In thousands)
	Years ended March 31,	2014			2013			2012
	Central nervous system (CNS)	$	2,124,573		$	2,017,199		$	3,715,112
	Cardiovascular		553,092			483,733			381,621
	Gastrointestinal		265,127			23,728			-
	Respiratory		207,536			100,920			31,203
	Other		353,018			279,356			264,612
		$	3,503,346		$	2,904,936		$	4,392,548
Net sales to company's principal customers	'
	The following illustrates net sales to the Company’s principal customers:

		2014			2013			2012
	McKesson Drug Company		37	%		38	%		36	%
	AmerisourceBergen Corporation		26	%		20	%		20	%
	Cardinal Heath, Inc.		22	%		29	%		30	%

Accounts_receivable_Tables

Accounts receivable (Tables)	12 Months Ended
Accounts receivable (Tables)	Mar. 31, 2014
Accounts receivable [Abstract]	'
Accounts receivable	'
	Accounts receivable, net, consists of the following:

	(In thousands)
	As of March 31,	2014		2013
	Trade	$	514,836	$	403,331
	Other		62,018		74,701
		$	576,854	$	478,032

Inventories_Tables

Inventories (Tables)	12 Months Ended
Inventories (Tables)	Mar. 31, 2014
Inventories [Abstract]	'
Inventories, net of reserves for obsolescence	'
	Inventories, net of reserves for obsolescence, consist of the following:

	(In thousands)
	As of March 31,	2014		2013
	Raw materials	$	181,168	$	127,508
	Work in process		23,451		1,333
	Finished goods		408,045		265,060
		$	612,664	$	393,901

Fair_value_measurements_Tables

Fair value measurements (Tables)	12 Months Ended
Fair value measurements (Tables)	Mar. 31, 2014
Fair value measurements [Abstract]	'
Fair value hierarchy of financial assets	'
	The following table presents the level within the fair value hierarchy at which the Company’s financial assets are carried at fair value and measured on a recurring basis:

	(In thousands)	Fair value at			Quoted prices in active markets for identical assets		Significant other observable market inputs		Unobservable market inputs
		31-Mar-14			(Level 1)		(Level 2)		(Level 3)
	Description
	Money market accounts	$	1,030,599		$	1,030,599		-		-
	Municipal bonds and notes		12,357			-	$	12,357		-
	Commercial paper		242,805			2,850		239,955		-
	Variable rate demand notes		30,770			-		30,770		-
	Auction rate securities		3,123			-		-	$	3,123
	Certificates of deposit		32,988			-		32,988		-
	Corporate bonds		1,225,619			-		1,225,619		-
	Government agency bonds		111,304			-		111,304		-


	(In thousands)	Fair value at			Quoted prices in active markets for identical assets		Significant other observable market inputs		Unobservable market inputs
		31-Mar-13			(Level 1)		(Level 2)		(Level 3)
	Description
	Money market accounts	$	818,474		$	818,474		-		-
	Municipal bonds and notes		46,877			-	$	46,877		-
	Commercial paper		168,639			31,815		136,824		-
	Variable rate demand notes		1,500			-		1,500		-
	Auction rate securities		3,198			-		-	$	3,198
	Certificates of deposit		90,268			5,981		84,287		-
	Corporate bonds		1,509,870			-		1,509,870		-
	Government agency bonds		278,804			-		278,804		-
Investments measured at fair value on a recurring basis using unobservable inputs	'
	The following table presents a reconciliation of the Level 3 investments measured at fair value on a recurring basis using unobservable inputs:

	(In thousands)	Year ended
	(In thousands)	31-Mar-14
	Balance at beginning of period	$	3,198
	Sales		(75	)
	Unrealized gain/(loss)		-
	Balance at end of period	$	3,123

Marketable_securities_Tables

Marketable securities (Tables)	12 Months Ended
Marketable securities (Tables)	Mar. 31, 2014
Marketable securities [Abstract]	'
Available-for-sale debt securities	'
	Available-for-sale debt securities consist of the following:

		31-Mar-14
	(In thousands)			Gains in accumulated other comprehensive income		Losses in accumulated other comprehensive income


		Estimated fair value

	Current:
	Municipal bonds and notes	$	7,066	$	6	$	-
	Government agency bonds		24,802		24		(6	)
	Commercial paper		82,950		-		-
	Certificates of deposit		25,989		-		-
	Corporate bonds		232,207		488		(38	)
	Total current securities		373,014		518		(44	)

	Non-current:
	Municipal bonds and notes		5,291		22		-
	Government agency bonds		86,502		127		(146	)
	Commercial paper		2,850		-		-
	Certificates of deposit		3,000		-		-
	Corporate bonds		986,265		3,297		(2,126	)
	Auction rate notes		3,123		-		(752	)
	Variable rate notes		30,770		-		-
	Total non-current securities		1,117,801		3,446		(3,024	)

	Total available-for-sale debt securities	$	1,490,815	$	3,964	$	(3,068	)

		31-Mar-13
	(In thousands)			Gains in accumulated other comprehensive income		Losses in accumulated other comprehensive income


		Estimated fair value

	Current:
	Municipal bonds and notes	$	34,025	$	34	$	-
	Government agency bonds		87,227		125		(10	)
	Commercial paper		144,293		-		-
	Certificates of deposit		47,977		-		(2	)
	Corporate bonds		425,676		1,286		(33	)
	Total current securities		739,198		1,445		(45	)

	Non-current:
	Municipal bonds and notes		12,852		37		-
	Government agency bonds		186,577		434		(19	)
	Certificates of deposit		22,999		-		-
	Corporate bonds		1,084,194		5,290		(2,150	)
	Auction rate notes		3,198		-		(752	)
	Variable rate notes		1,500		-		-
	Total non-current securities		1,311,320		5,761		(2,921	)

	Total available-for-sale debt securities	$	2,050,518	$	7,206		(2,966	)
Contractual maturities of available-for-sale debt securities	'
	Contractual maturities of available-for-sale debt securities at March 31, 2014 are as follows:

	(In thousands)
		Estimated fair value
	Within one year	$	373,014
	1-5 years		1,078,986
	5-10 years		2,300
	After 10 years		36,515
		$	1,490,815

Goodwill_and_intangible_assets1

Goodwill and intangible assets (Tables)	12 Months Ended
Goodwill and intangible assets (Tables)	Mar. 31, 2014
Goodwill and intangible assets [Abstract]	'
Schedule of carrying amount of goodwill	'
	The changes in the carrying amount of goodwill for the years ended March 31, 2014 and 2013 are as follows:

	(In thousands)	Gross carrying amount
	Balance at March 31, 2012	$	713,091
	Acquisitions/Dispositions		-
	Balance at March 31, 2013		713,091
	Acquisition of Aptalis		335,417
	Balance at March 31, 2014	$	1,048,508
License agreements, product rights and other intangibles	'
	License agreements, product rights and other intangibles consist of the following:

	(In thousands)	31-Mar-14				31-Mar-13
		Gross carrying amount		Accumulated amortization		Gross carrying amount		Accumulated amortization
	Amortized intangible assets:
	License agreements	$	1,803,425	$	249,088	$	1,528,114	$	160,805
	Product rights		3,005,025		98,903		89,407		61,472
	Buy-out of royalty agreements		798,617		114,737		798,617		66,222
	In process research and development		16,600		-		-		-
	Trade names		34,190		34,190		34,190		34,190
	Total	$	5,657,857	$	496,918	$	2,450,328	$	322,689

Future annual amortization expense	'
	Future annual amortization expense expected is as follows:

	(In thousands)
	Years ended March 31,
	2015	$	369,673
	2016		419,438
	2017		432,454
	2018		483,149
	2019		526,084
		$	2,230,798

Accrued_expenses_Tables

Accrued expenses (Tables)	12 Months Ended
Accrued expenses (Tables)	Mar. 31, 2014
Accrued expenses [Abstract]	'
Accrued expenses	'
	Accrued expenses consist of the following:

	(In thousands)
	As of March 31,	2014		2013
	Managed care and Medicaid rebates	$	302,389	$	230,173
	Employee compensation and other benefits		211,753		181,995
	Clinical research and development costs		172,122		129,663
	Restructuring		74,104		-
	Other		529,276		298,511
		$	1,289,644	$	840,342

Commitments_Tables

Commitments (Tables)	12 Months Ended
Commitments (Tables)	Mar. 31, 2014
Commitments [Abstract]	'
Future minimum rental payments under non-cancellable leases	'
	Future minimum rental payments under non-cancellable leases are as follows:


	(In thousands)
	Years ended March 31,
	2015	$	45,874
	2016		36,074
	2017		28,757
	2018		20,084
	2019		14,589
	Thereafter		84,120
		$	229,498

Stockholders_equity_Tables

Stockholders' equity (Tables)	12 Months Ended
Stockholders' equity (Tables)	Mar. 31, 2014
Stockholders' equity [Abstract]	'
Schedule of options outstanding and exercisable, by range of exercise prices	'
	The following table summarizes information about stock options outstanding at March 31, 2014:

				Options outstanding												Options exercisable
	Range of exercise prices			Number				Weighted average remaining contractual life				Weighted average exercise price				Number		Weighted average exercise price
	Range of exercise prices			outstanding				(in years)				Weighted average exercise price				exercisable		Weighted average exercise price

	$20.55 to $30.00				2,364				6.8			$	28.24				1,218	$	26.9
	30.01 to 50.00				9,504				7.2				36.49				3,169		36.04
	50.01 to 96.42				582				4.3				54.55				448		51.54
					12,450				7				35.77				4,835		35.17
Share-based compensation awards	'
	Transactions under the stock option plan are summarized as follows:

	(In thousands)	Options				Weighted average			Weighted	Aggregate
						exercise price			average	intrinsic value
									remaining
									contractual life
									(in years)
	Stock options:
	Outstanding at March 31, 2011 (at $20.55 to $63.44 per share)		17,085			$	36.9
	Granted (at $30.00 to $34.49 per share)		3,758				31.04
	Exercised (at $20.55 to $39.88 per share)		(351	)			28.19
	Forfeited and Expired		(3,249	)			39.89

	Outstanding at March 31, 2012 (at $20.55 to $59.05 per share)		17,243			$	35.24
	Granted (at $34.04 to $38.10 per share)		2,368				34.26
	Exercised (at $31.28 to $38.45 per share)		(1,137	)			28.52
	Forfeited and Expired		(2,923	)			43.7

	Outstanding at March 31, 2013 (at $20.55 to $59.05 per share)		15,551			$	34.03
	Granted (at $37.88 to $96.42 per share)		4,155				40.31
	Exercised (at $35.34 to $100.66 per share)		(5,261	)			32.91
	Forfeited and Expired		(1,995	)			39.27

	Outstanding at March 31, 2014 (at $20.55 to $96.42 per share)		12,450			$	35.77		7	$703,525

	Exercisable at March 31, 2014		4,835			$	35.17		4.9	$276,098

		Restricted Stock								Performance Stock Units
		Shares/ Units				Weighted average grant date fair value				Units				Weighted average grant date fair value
	Restricted stock:
	Outstanding at March 31, 2011		2,275			$	30.72
	Granted		1,239				30.43
	Vested		(928	)			30.66
	Forfeited		(101	)			30.62

	Outstanding at March 31, 2012		2,485			$	30.6				-				-
	Granted		613				34.27				410			$	36.12
	Vested		(1,047	)			30.13				-				-
	Forfeited		(88	)			31.86				-				-

	Outstanding at March 31, 2013		1,963			$	31.96				410			$	36.12
	Granted		1,133				40.68				217				45.35
	Vested		(973	)			31.77				-				-
	Forfeited		(395	)			34.79				(49	)			39.96

	Outstanding at March 31, 2014		1,728			$	37.14				578			$	36.04

Income_taxes_Tables

Income taxes (Tables)	12 Months Ended
Income taxes (Tables)	Mar. 31, 2014
Income taxes [Abstract]	'
Components of income (loss) before income tax expense	'
	The components of income (loss) before income tax expense were:

	(In thousands)
	Years ended March 31,	2014			2013			2012
	U.S.	$	(242,233	)	$	(21,334	)	$	325,882
	Foreign		323,801			(23,524	)		911,806
	Income (loss) before income tax expense (benefit)	$	81,568		$	(44,858	)	$	1,237,688

Components of provision for income taxes	'
	The provision for income taxes consists of the following:

	(In thousands)
	Years ended March 31,	2014			2013			2012
	Current:
	U.S. federal	$	9,616		$	20,134		$	222,012
	State and local		(5,087	)		(8,258	)		26,984
	Foreign		17,583			10,176			52,452
			22,112			22,052			301,448
	Deferred:
	U.S.		(96,236	)		(33,959	)		(41,970	)
	Foreign		(9,618	)		(848	)		(848	)
			(105,854	)		(34,807	)		(42,818	)
		$	(83,742	)	$	(12,755	)	$	258,630
Reconciliation between provision for income taxes and expected federal income taxes at statutory rate	'
	The reasons for the difference between the provision for income taxes and expected federal income taxes at statutory rates are as follows:

	Years ended March 31, (percentage of income	2014			2013			2012
	before income tax expense)	2014			2013			2012
	U.S. statutory rate		35	%		35	%		35	%
	Effect of foreign operations		(79.1	)		(88.8	)		(16.1	)
	Research credit		(16.0	)		46			(1.0	)
	State and local taxes, less federal tax benefit		7.7			(16.9	)		1.4
	Unrecognized tax benefit – audit settlement and statute expiration		(47.9	)		54.7			0
	Permanent differences and other items		(2.4	)		(1.6	)		1.6
			(102.7	)%		28.4	%		20.9	%
Schedule of net deferred income taxes	'
	Net deferred income taxes relate to the following timing differences:

	(In thousands)
	Years ended March 31,	2014			2013
	Inventory reserves	$	38,905		$	42,924
	Receivable allowances and other reserves		60,795			37,169
	Property, plant and equipment		(37,201	)		(24,302	)
	Intangible assets		(818,867	)		(255,260	)
	Carryforwards and credits		245,454			64,378
	Accrued liabilities		102,263			65,193
	Employee stock option tax benefits		36,436			41,726
	Other (includes reserve for legal contingencies)		24,226			21,169
			(347,989	)		(7,003	)
	Valuation allowance		(118,488	)		(9,787	)
	Deferred taxes, net	$	(466,477	)	$	(16,790	)
Reconciliation of beginning and ending amount of unrecognized tax benefits	'
	A reconciliation of the beginning and ending amount of UTBs is as follows:

	(In thousands)	2014			2013
	Balance at beginning of period	$	492,088		$	498,292
	Additions related to prior year positions		18,000			2,011
	Reductions related to prior year positions		-			(1,630	)
	Reduction related to audit settlement		(73,048	)		(7,806	)
	Reduction related to statute expiration		(14,264	)		(11,500	)
	Additions related to current year positions		9,694			12,721
	Other		4,572			-
	Balance as of March 31	$	437,042		$	492,088

Quarterly_financial_data_unaud1

Quarterly financial data (unaudited) (Tables)	12 Months Ended
Quarterly financial data (unaudited) (Tables)	Mar. 31, 2014
Quarterly financial data (unaudited) [Abstract]	'
Quarterly financial data	'

	(In thousands)	Net sales		Gross profit		Net income (loss)			Diluted earnings (loss) per share
	2014
	First quarter	$	796,853	$	663,404	$	23,278		$	0.09
	Second quarter		811,429		683,736		69,987			0.26
	Third quarter		846,784		696,126		17,961			0.07
	Fourth quarter		1,048,280		842,991		54,084			0.2

	2013
	First quarter	$	751,766	$	649,378	$	55,285		$	0.21
	Second quarter		692,017		596,571		20,777			0.08
	Third quarter		677,967		562,970		(153,608	)		(0.58	)
	Fourth quarter		783,186		636,000		45,443			0.17

License_and_collaboration_agre1

License and collaboration agreements (Tables)	12 Months Ended
License and collaboration agreements (Tables)	Mar. 31, 2014
License and collaboration agreements [Abstract]	'
Schedule of activity related to Collaborative Arrangement	'
	The following illustrates activity related to the Ironwood collaboration agreement for the periods presented:

	(In thousands)	Year ended March 31,
		2014			2013			2012
	Revenue
	Net Sales of Linzess	$	175,063		$	23,728		$	--
	Cost of sales
	Cost of sales of Linzess		7,448			1,010			--
	SG&A
	Payment to/ (receipt from) Ironwood for the Commercialization pool		(5,371	)		(39,244	)		(2,425	)
	R&D
	Payment to/ (receipt from) Ironwood for the Development pool		1,510			(4,368	)		2,884	)

Business_combinations_Tables

Business combinations (Tables)	12 Months Ended
Business combinations (Tables)	Mar. 31, 2014
Business combinations [Abstract]	'
Allocation of total purchase price	'
	The following table summarizes the fair values of the assets acquired, including goodwill and intangible assets, and liabilities assumed as of the acquisition date. These amounts are provisional and subject to change:

	(In thousands)
	Assets acquired/liabilities assumed	Fair value at acquisition date
	Accounts receivable, net	$	122,077
	Inventories, net		141,750
	Other current assets		27,971
	Property, plant and equipment, net		103,762
	Intangible assets, net		2,928,800
	Other assets		2,236
	Accounts payable and accrued liabilities		(153,575	)
	Other current liabilities		(17,936	)
	Long term deferred tax liabilities		(548,768	)
	Other long term liabilities		(41,734	)
	Total identifiable net assets acquired		2,564,583
	Goodwill		335,417
	Total	$	2,900,000

	Cash on hand at acquisition		112,286
	Total cash transferred at acquisition	$	3,012,286
Schedule of unaudited pro forma information	'
	The following unaudited pro forma information gives effect to the Company’s acquisition of Aptalis as if the acquisition had occurred on April 1, 2012 and had been included in the Company’s consolidated results of operations for the years ended March 31, 2014 and March 31, 2013:

	(In thousands, except per share data)
	Years ended March 31,	2014			2013
	Net sales	$	4,079,156		$	3,551,193
	Net loss		(69,023	)		(148,355	)
	Basic loss per share		(0.26	)		(0.56	)
	Diluted net loss per share		(0.26	)		(0.56	)

Restructuring_initiative_Table

Restructuring initiative (Tables)	12 Months Ended
Restructuring initiative (Tables)	Mar. 31, 2014
Restructuring initiative [Abstract]	'
Liability balance for the cost savings initiative	'
	The liability balance for the cost savings initiative as of March 31, 2014 is as follows:

	(In thousands)
		Post-Employment			Consulting			Total
		Benefits			Fees & Other			Total
	Beginning Balance as of October 1, 2013	$	-		$	-		$	-
	Expenses		59,273			19,953			79,226
	Cash Payments		(2,384	)		(10,034	)		(12,418	)
	Balance as of March 31, 2014	$	56,889		$	9,919		$	66,808

Summary_of_significant_account3

Summary of significant accounting policies (Details) (USD $)	12 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2012
	Segment	Mar. 31, 2013	Mar. 31, 2012
Property, Plant and Equipment [Line Items]	'	'	'
Property, plant and equipment	$700,250,000	$739,702,000	'
Less: accumulated depreciation	328,435,000	362,742,000	'
Property, plant and equipment, net	371,815,000	376,960,000	'
Estimated cost to complete	67,700,000	'	'
Number of segment	1	'	'
Revenue Recognition [Abstract]	'	'	'
Number of weeks before settlement of deductions for chargebacks, lower range	'14 days	'	'
Number of weeks before settlement of deductions for chargebacks, upper range	'21 days	'	'
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]	'	'	'
Amount of accumulated other comprehensive income, foreign currency translation	12,400,000	1,400,000	'
Amount of accumulated other comprehensive income, pension liability adjustments	-2,100,000	-8,800,000	'
Amount of accumulated other comprehensive income, unrealized gain (losses) on securities	1,800,000	17,500,000	'
Income Tax Uncertainties [Abstract]	'	'	'
Percentage of likelihood before tax benefits be recognized	'greater than 50 percent	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'
Compensation expense	69,051,000	64,725,000	59,317,000
Stock Compensation Plan [Member]	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'
Compensation expense	69,100,000	64,700,000	59,300,000
Compensation expense, net of tax	46,100,000	45,700,000	44,300,000
Weighted average period of compensation cost is expected to be recognized	'2 years 3 months 18 days	'	'
Amount of unrecognized compensation cost for unvested stock options	125,000,000	'	'
Summary of weighted average assumptions used in determining fair value of stock options [Abstract]	'	'	'
Expected dividend yield (in hundredths)	0.00%	0.00%	0.00%
Expected stock price volatility (in hundredths)	23.26%	25.10%	27.49%
Risk-free interest rate (in hundredths)	1.50%	1.20%	1.40%
Expected life of options (years)	'7 years	'7 years	'7 years
Savings and Profit Sharing Plan [Member]	'	'	'
Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits [Line Items]	'	'	'
Employer contributions	43,500,000	45,900,000	43,400,000
Land [Member]	'	'	'
Property, Plant and Equipment [Line Items]	'	'	'
Property, plant and equipment	26,827,000	32,740,000	'
Buildings and Improvements [Member]	'	'	'
Property, Plant and Equipment [Line Items]	'	'	'
Property, plant and equipment	183,427,000	294,370,000	'
Buildings and Improvements [Member] \| Minimum [Member]	'	'	'
Property, Plant and Equipment [Line Items]	'	'	'
Property, plant and equipment, useful life	'10 years	'	'
Buildings and Improvements [Member] \| Maximum [Member]	'	'	'
Property, Plant and Equipment [Line Items]	'	'	'
Property, plant and equipment, useful life	'50 years	'	'
Machinery, Equipment and Other [Member]	'	'	'
Property, Plant and Equipment [Line Items]	'	'	'
Property, plant and equipment	427,584,000	373,385,000	'
Machinery, Equipment and Other [Member] \| Minimum [Member]	'	'	'
Property, Plant and Equipment [Line Items]	'	'	'
Property, plant and equipment, useful life	'3 years	'	'
Machinery, Equipment and Other [Member] \| Maximum [Member]	'	'	'
Property, Plant and Equipment [Line Items]	'	'	'
Property, plant and equipment, useful life	'10 years	'	'
Construction in Progress [Member]	'	'	'
Property, Plant and Equipment [Line Items]	'	'	'
Property, plant and equipment	62,412,000	39,207,000	'
moksha8 [Member]	'	'	'
Long-term receivables [Abstract]	'	'	'
Long term receivables, net	$101,900,000	'	'

Net_income_loss_per_share_Deta

Net income (loss) per share (Details) (USD $)	12 Months Ended
In Billions, except Share data, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2012
Reconciliation of shares used in calculating basic and diluted net income per share [Abstract]	'	'	'
Basic (in shares)	269,129,000	266,807,000	273,561,000
Incremental shares attributable to share based compensation plans (in shares)	3,818,000	0	455,000
Diluted (in shares)	272,947,000	266,807,000	274,016,000
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]	'	'	'
Number of shares authorized to repurchase under previous plan (in shares)	50,000,000	'	'
Stock repurchase amount authorized	$1	'	'
Anti-Dilutive Options [Member]	'	'	'
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]	'	'	'
Anti-dilutive options to purchase common stock outstanding during the period (in shares)	1,300,000	15,600,000	14,400,000
Exercise price range, lower range limit (in dollars per share)	$42.61	20.55	26.18
Exercise price range, upper range limit (in dollars per share)	$96.42	59.05	59.05
Contract Expiration	31-Mar-24	'	'

Business_operations_Details

Business operations (Details) (USD $)	3 Months Ended								12 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2012
	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Segment	Mar. 31, 2013	Mar. 31, 2012
Business operations [Abstract]	'	'	'	'	'	'	'	'	'	'	'
Number of operating segments	'	'	'	'	'	'	'	'	1	'	'
Net Sales and Long lived Assets in Individual Foreign Countries by Country [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Net sales	$1,048,280	$846,784	$811,429	$796,853	$783,186	$677,967	$692,017	$751,766	$3,503,346	$2,904,936	$4,392,548
Long-lived assets	6,581,262	'	'	'	3,217,690	'	'	'	6,581,262	3,217,690	3,177,159
Net Sales to Principal Customers [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Percentage of net sales generated from CNS franchise's revenues (in hundredths)	'	'	'	'	'	'	'	'	61.00%	69.00%	85.00%
McKesson Drug Company [Member]	'	'	'	'	'	'	'	'	'	'	'
Net Sales to Principal Customers [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Net sales percentage by principal customers (in hundredths)	'	'	'	'	'	'	'	'	37.00%	38.00%	36.00%
Amerisource Bergen Corporation [Member]	'	'	'	'	'	'	'	'	'	'	'
Net Sales to Principal Customers [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Net sales percentage by principal customers (in hundredths)	'	'	'	'	'	'	'	'	26.00%	20.00%	20.00%
Cardinal Health, Inc [Member]	'	'	'	'	'	'	'	'	'	'	'
Net Sales to Principal Customers [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Net sales percentage by principal customers (in hundredths)	'	'	'	'	'	'	'	'	22.00%	29.00%	30.00%
Central Nervous System [Member]	'	'	'	'	'	'	'	'	'	'	'
Net Sales and Long lived Assets in Individual Foreign Countries by Country [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Net sales	'	'	'	'	'	'	'	'	2,124,573	2,017,199	3,715,112
Cardiovascular [Member]	'	'	'	'	'	'	'	'	'	'	'
Net Sales and Long lived Assets in Individual Foreign Countries by Country [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Net sales	'	'	'	'	'	'	'	'	553,092	483,733	381,621
Gastrointestinal [Member]	'	'	'	'	'	'	'	'	'	'	'
Net Sales and Long lived Assets in Individual Foreign Countries by Country [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Net sales	'	'	'	'	'	'	'	'	265,127	23,728	0
Respiratory [Member]	'	'	'	'	'	'	'	'	'	'	'
Net Sales and Long lived Assets in Individual Foreign Countries by Country [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Net sales	'	'	'	'	'	'	'	'	207,536	100,920	31,203
Other [Member]	'	'	'	'	'	'	'	'	'	'	'
Net Sales and Long lived Assets in Individual Foreign Countries by Country [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Net sales	'	'	'	'	'	'	'	'	353,018	279,356	264,612
United States [Member]	'	'	'	'	'	'	'	'	'	'	'
Net Sales and Long lived Assets in Individual Foreign Countries by Country [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Net sales	'	'	'	'	'	'	'	'	3,329,367	2,769,541	4,261,976
Long-lived assets	707,784	'	'	'	432,085	'	'	'	707,784	432,085	386,427
Ireland [Member]	'	'	'	'	'	'	'	'	'	'	'
Net Sales and Long lived Assets in Individual Foreign Countries by Country [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Net sales	'	'	'	'	'	'	'	'	74,360	60,014	61,747
Long-lived assets	3,949,311	'	'	'	2,759,428	'	'	'	3,949,311	2,759,428	2,759,069
United Kingdom [Member]	'	'	'	'	'	'	'	'	'	'	'
Net Sales and Long lived Assets in Individual Foreign Countries by Country [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Net sales	'	'	'	'	'	'	'	'	76,043	75,381	68,825
Long-lived assets	23,608	'	'	'	26,177	'	'	'	23,608	26,177	31,663
Canada [Member]	'	'	'	'	'	'	'	'	'	'	'
Net Sales and Long lived Assets in Individual Foreign Countries by Country [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Net sales	'	'	'	'	'	'	'	'	5,725	0	0
Long-lived assets	1,792,332	'	'	'	0	'	'	'	1,792,332	0	0
Italy [Member]	'	'	'	'	'	'	'	'	'	'	'
Net Sales and Long lived Assets in Individual Foreign Countries by Country [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Net sales	'	'	'	'	'	'	'	'	8,166	0	0
Long-lived assets	78,356	'	'	'	0	'	'	'	78,356	0	0
Other [Member]	'	'	'	'	'	'	'	'	'	'	'
Net Sales and Long lived Assets in Individual Foreign Countries by Country [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Net sales	'	'	'	'	'	'	'	'	9,685	0	0
Long-lived assets	$29,871	'	'	'	$0	'	'	'	$29,871	$0	$0

Accounts_receivable_Details

Accounts receivable (Details) (USD $)	Mar. 31, 2014	Mar. 31, 2013
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'
Accounts receivable, net	$576,854	$478,032
Trade [Member]	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'
Accounts receivable, net	514,836	403,331
Other [Member]	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'
Accounts receivable, net	$62,018	$74,701

Inventories_Details

Inventories (Details) (USD $)	Mar. 31, 2014	Mar. 31, 2013
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Inventories [Abstract]	'	'
Raw materials	$181,168	$127,508
Work in process	23,451	1,333
Finished goods	408,045	265,060
Inventories, net	$612,664	$393,901

Fair_value_measurements_Detail

Fair value measurements (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]	'	'
Money market accounts	$1,030,599	$818,474
Municipal bonds and notes	12,357	46,877
Commercial paper	242,805	168,639
Variable rate demand notes	30,770	1,500
Auction rate securities	3,123	3,198
Certificates of deposit	32,988	90,268
Corporate bonds	1,225,619	1,509,870
Government agency bonds	111,304	278,804
Reconciliation of Level 3 investments measured at fair value on a recurring basis using unobservable inputs [Roll Forward]	'	'
Balance at beginning of period	3,198	'
Sales	-75	'
Unrealized gain/(loss)	0	'
Balance at end of period	3,123	3,198
Purchase of level 3 investments	0	0
Maturity period of Auction Rate Securities	'20 years	'
Long-term debt carrying value	3,000,000	0
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]	'	'
Money market accounts	1,030,599	818,474
Municipal bonds and notes	0	0
Commercial paper	2,850	31,815
Variable rate demand notes	0	0
Auction rate securities	0	0
Certificates of deposit	0	5,981
Corporate bonds	0	0
Government agency bonds	0	0
Significant Other Observable Market Inputs (Level 2) [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]	'	'
Money market accounts	0	0
Municipal bonds and notes	12,357	46,877
Commercial paper	239,955	136,824
Variable rate demand notes	30,770	1,500
Auction rate securities	0	0
Certificates of deposit	32,988	84,287
Corporate bonds	1,225,619	1,509,870
Government agency bonds	111,304	278,804
Unobservable Market Inputs (Level 3) [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]	'	'
Money market accounts	0	0
Municipal bonds and notes	0	0
Commercial paper	0	0
Variable rate demand notes	0	0
Auction rate securities	3,123	3,198
Certificates of deposit	0	0
Corporate bonds	0	0
Government agency bonds	$0	$0

Marketable_securities_Details

Marketable securities (Details) (USD $)	3 Months Ended	12 Months Ended
Marketable securities (Details) (USD $)	Mar. 31, 2014	Mar. 31, 2014	Mar. 31, 2013	Jun. 30, 2013
Schedule of Available-for-sale Securities [Line Items]	'	'	'	'
Total available-for-sale debt securities: Estimated fair value	$1,490,815,000	$1,490,815,000	$2,050,518,000	'
Total available-for-sale debt securities: Gains in accumulated other comprehensive income	'	3,964,000	7,206,000	'
Total available-for-sale debt securities: Losses in accumulated other comprehensive income	'	-3,068,000	-2,966,000	'
Proceeds from sales of available-for-sale debt securities	'	1,900,000,000	3,000,000,000	'
Gross realized gains on sales of available-for-sale debt securities	'	1,700,000	1,300,000	'
Net unrealized holding gains (losses) on available-for-sale debt securities	'	900,000	4,200,000	'
Investment in Ironwood Pharmaceuticals, Inc.	25,700,000	25,700,000	38,100,000	'
Investment in Trevena, Inc.	'	'	'	30,000,000
Purchase of additional Trevena Common Stock	3,000,000	'	'	'
Fair Value of Trevena, Inc.	26,700,000	26,700,000	'	'
Contractual maturities of available-for-sale debt securities, fair value [Abstract]	'	'	'	'
Within one year	373,014,000	373,014,000	'	'
1-5 years	1,078,986,000	1,078,986,000	'	'
5-10 years	2,300,000	2,300,000	'	'
After 10 years	36,515,000	36,515,000	'	'
Total available-for-sale debt securities: Estimated fair value	1,490,815,000	1,490,815,000	2,050,518,000	'
Current [Member]	'	'	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'	'	'
Estimated fair value, current	373,014,000	373,014,000	739,198,000	'
Gains in accumulated other comprehensive income	'	518,000	1,445,000	'
Losses in accumulated other comprehensive income	'	-44,000	-45,000	'
Noncurrent [Member]	'	'	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'	'	'
Estimated fair value, non-current	1,117,801,000	1,117,801,000	1,311,320,000	'
Gains in accumulated other comprehensive income	'	3,446,000	5,761,000	'
Losses in accumulated other comprehensive income	'	-3,024,000	-2,921,000	'
Municipal Bonds and Notes [Member] \| Current [Member]	'	'	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'	'	'
Estimated fair value, current	7,066,000	7,066,000	34,025,000	'
Gains in accumulated other comprehensive income	'	6,000	34,000	'
Losses in accumulated other comprehensive income	'	0	0	'
Municipal Bonds and Notes [Member] \| Noncurrent [Member]	'	'	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'	'	'
Estimated fair value, non-current	5,291,000	5,291,000	12,852,000	'
Gains in accumulated other comprehensive income	'	22,000	37,000	'
Losses in accumulated other comprehensive income	'	0	0	'
Government Agency Bonds [Member} \| Current [Member]	'	'	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'	'	'
Estimated fair value, current	24,802,000	24,802,000	87,227,000	'
Gains in accumulated other comprehensive income	'	24,000	125,000	'
Losses in accumulated other comprehensive income	'	-6,000	-10,000	'
Government Agency Bonds [Member} \| Noncurrent [Member]	'	'	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'	'	'
Estimated fair value, non-current	86,502,000	86,502,000	186,577,000	'
Gains in accumulated other comprehensive income	'	127,000	434,000	'
Losses in accumulated other comprehensive income	'	-146,000	-19,000	'
Commercial Paper [Member] \| Current [Member]	'	'	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'	'	'
Estimated fair value, current	82,950,000	82,950,000	144,293,000	'
Gains in accumulated other comprehensive income	'	0	0	'
Losses in accumulated other comprehensive income	'	0	0	'
Commercial Paper [Member] \| Noncurrent [Member]	'	'	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'	'	'
Estimated fair value, non-current	2,850,000	2,850,000	'	'
Gains in accumulated other comprehensive income	'	0	'	'
Losses in accumulated other comprehensive income	'	0	'	'
Certificates of Deposit [Member] \| Current [Member]	'	'	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'	'	'
Estimated fair value, current	25,989,000	25,989,000	47,977,000	'
Gains in accumulated other comprehensive income	'	0	0	'
Losses in accumulated other comprehensive income	'	0	-2,000	'
Certificates of Deposit [Member] \| Noncurrent [Member]	'	'	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'	'	'
Estimated fair value, non-current	3,000,000	3,000,000	22,999,000	'
Gains in accumulated other comprehensive income	'	0	0	'
Losses in accumulated other comprehensive income	'	0	0	'
Corporate Bonds [Member] \| Current [Member]	'	'	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'	'	'
Estimated fair value, current	232,207,000	232,207,000	425,676,000	'
Gains in accumulated other comprehensive income	'	488,000	1,286,000	'
Losses in accumulated other comprehensive income	'	-38,000	-33,000	'
Corporate Bonds [Member] \| Noncurrent [Member]	'	'	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'	'	'
Estimated fair value, non-current	986,265,000	986,265,000	1,084,194,000	'
Gains in accumulated other comprehensive income	'	3,297,000	5,290,000	'
Losses in accumulated other comprehensive income	'	-2,126,000	-2,150,000	'
Auction Rate Notes [Member] \| Noncurrent [Member]	'	'	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'	'	'
Estimated fair value, non-current	3,123,000	3,123,000	3,198,000	'
Gains in accumulated other comprehensive income	'	0	0	'
Losses in accumulated other comprehensive income	'	-752,000	-752,000	'
Variable Rate Notes [Member] \| Noncurrent [Member]	'	'	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'	'	'
Estimated fair value, non-current	30,770,000	30,770,000	1,500,000	'
Gains in accumulated other comprehensive income	'	0	0	'
Losses in accumulated other comprehensive income	'	$0	$0	'

Goodwill_and_intangible_assets2

Goodwill and intangible assets (Details) (USD $)	12 Months Ended
Goodwill and intangible assets (Details) (USD $)	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2012
Goodwill [Roll Forward]	'	'	'
Balance	$713,091,000	$713,091,000	'
Acquisitions/Dispositions	335,417,000	0	'
Balance	1,048,508,000	713,091,000	713,091,000
Amortized intangible assets [Abstract]	'	'	'
Gross carrying amount	5,657,857,000	2,450,328,000	'
Accumulated amortization	496,918,000	322,689,000	'
Amortization expense	174,229,000	99,999,000	80,905,000
Finite-Lived Intangible Assets, Future Amortization Expense [Abstract]	'	'	'
2015	369,673,000	'	'
2016	419,438,000	'	'
2017	432,454,000	'	'
2018	483,149,000	'	'
2019	526,084,000	'	'
Future expected amortization expense	2,230,798,000	'	'
Licensing Agreements [Member]	'	'	'
Amortized intangible assets [Abstract]	'	'	'
Gross carrying amount	1,803,425,000	1,528,114,000	'
Accumulated amortization	249,088,000	160,805,000	'
Addition of intangible assets during the period	231,000,000	'	'
Product Rights [Member]	'	'	'
Amortized intangible assets [Abstract]	'	'	'
Gross carrying amount	3,005,025,000	89,407,000	'
Accumulated amortization	98,903,000	61,472,000	'
Addition of intangible assets during the period	2,900,000,000	'	'
Buy-out of royalty agreements [Member]	'	'	'
Amortized intangible assets [Abstract]	'	'	'
Gross carrying amount	798,617,000	798,617,000	'
Accumulated amortization	114,737,000	66,222,000	'
In process research and development [Member]	'	'	'
Amortized intangible assets [Abstract]	'	'	'
Gross carrying amount	16,600,000	0	'
Accumulated amortization	0	0	'
Addition of intangible assets during the period	16,600,000	'	'
Trade Names [Member]	'	'	'
Amortized intangible assets [Abstract]	'	'	'
Gross carrying amount	34,190,000	34,190,000	'
Accumulated amortization	$34,190,000	$34,190,000	'

Accrued_expenses_Details

Accrued expenses (Details) (USD $)	Mar. 31, 2014	Sep. 30, 2013	Mar. 31, 2013
In Thousands, unless otherwise specified	Mar. 31, 2014	Sep. 30, 2013	Mar. 31, 2013
Accrued expenses [Abstract]	'	'	'
Managed care and Medicaid rebates	$302,389	'	$230,173
Employee compensation and other benefits	211,753	'	181,995
Clinical research and development costs	172,122	'	129,663
Restructuring	74,104	0	0
Other	529,276	'	298,511
Total	$1,289,644	'	$840,342

Debt_and_debt_facility_Details

Debt and debt facility (Details) (USD $)	12 Months Ended			12 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	29-May-14	Mar. 31, 2014	Mar. 31, 2014	Mar. 31, 2014	Mar. 31, 2014
	Mar. 31, 2014	Mar. 31, 2013	Subsequent Event [Member]	Senior Unsecured Notes [Member]	4.375% senior unsecured notes due 2019 [Member]	4.875% senior unsecured notes due 2021 [Member]	5.00% Senior Notes [Member]
Debt Instrument [Line Items]	'	'	'	'	'	'	'
Issuance date of senior notes	'	'	'	31-Jan-14	'	'	10-Dec-13
Issuance of aggregate principal senior unsecured notes	'	'	'	$1,800,000,000	$1,050,000,000	$750,000,000	'
Stated interest rate of unsecured senior notes (in hundredths)	'	'	'	'	4.38%	4.88%	'
Senior Notes	3,000,000,000	0	'	'	'	'	1,200,000,000
Interest rate on senior notes (in hundredths)	'	'	'	'	'	'	5.00%
Maturity date of senior notes	'	'	'	'	1-Feb-19	15-Feb-21	15-Dec-21
Deferred financing costs	'	'	'	22,500,000	'	'	18,500,000
Interest expense	'	'	'	11,800,000	'	'	18,400,000
Amortization of deferred financing fees	'	'	'	600,000	'	'	700,000
Senior notes fair value	'	'	'	1,900,000,000	'	'	1,300,000,000
Issuance Date	4-Dec-12	'	'	'	'	'	'
Current borrowing capacity	750,000,000	'	'	'	'	'	'
Expiration Date	4-Dec-17	'	'	'	'	'	'
Maximum borrowing capacity	1,000,000,000	'	'	'	'	'	'
Available borrowing capacity	'	'	750,000,000	'	'	'	'
Issued letters of credit	'	'	$8,500,000	'	'	'	'

Commitments_Details

Commitments (Details) (USD $)	12 Months Ended
Commitments (Details) (USD $)	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2012
Commitments [Abstract]	'	'	'
Rent expense	$51,100,000	$45,300,000	$39,500,000
Future minimum rental payments under non-cancellable leases [Abstract]	'	'	'
2015	45,874,000	'	'
2016	36,074,000	'	'
2017	28,757,000	'	'
2018	20,084,000	'	'
2019	14,589,000	'	'
Thereafter	84,120,000	'	'
Total	229,498,000	'	'
Potential future development milestone payments	552,000,000	'	'
Potential future research and development milestones	183,000,000	'	'
Potential future regulatory milestones	369,000,000	'	'
Potential future sales milestones	340,000,000	'	'
Amount of inventory purchase commitments	$169,300,000	'	'

Stockholders_equity_Details

Stockholders' equity (Details) (USD $)	12 Months Ended
Stockholders' equity (Details) (USD $)	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2012	Mar. 31, 2011
Changes in options outstanding, additional disclosures [Abstract]	'	'	'	'
Shares available for grant (in shares)	31,600,000	'	'	'
2007 Equity Incentive Plan [Member]	'	'	'	'
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]	'	'	'	'
Shares authorized to be issued to employees under 2007 plan (in shares)	28,000,000	'	'	'
Amended 2007 Equity Incentive Plan [Member]	'	'	'	'
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]	'	'	'	'
Shares authorized to be issued to employees under 2007 plan (in shares)	57,000,000	'	'	'
Restricted Stock [Member]	'	'	'	'
Changes in options outstanding, additional disclosures [Abstract]	'	'	'	'
Total intrinsic value of restricted stock vested during the period	$51,800,000	$37,500,000	$28,600,000	'
Summary of Restricted Stock and Performance Stock Units activity [Roll Forward]	'	'	'	'
Outstanding, beginning of period (in shares)	1,963,000	2,485,000	2,275,000	'
Granted (in shares)	1,133,000	613,000	1,239,000	'
Vested (in shares)	-973,000	-1,047,000	-928,000	'
Forfeited (in shares)	-395,000	-88,000	-101,000	'
Outstanding, end of period (in shares)	1,728,000	1,963,000	2,485,000	'
Changes in restricted stock and performance stock units, additional disclosures [Abstract]	'	'	'	'
Outstanding, beginning of period (in dollar per share)	$31.96	$30.60	$30.72	'
Granted (in dollar per share)	$40.68	$34.27	$30.43	'
Vested (in dollar per share)	$31.77	$30.13	$30.66	'
Forfeited (in dollar per share)	$34.79	$31.86	$30.62	'
Outstanding, end of period (in dollars per share)	$37.14	$31.96	$30.60	'
Performance Stock Units [Member]	'	'	'	'
Summary of Restricted Stock and Performance Stock Units activity [Roll Forward]	'	'	'	'
Outstanding, beginning of period (in shares)	410,000	0	'	'
Granted (in shares)	217,000	410,000	'	'
Vested (in shares)	0	0	'	'
Forfeited (in shares)	-49,000	0	'	'
Outstanding, end of period (in shares)	578,000	410,000	'	'
Changes in restricted stock and performance stock units, additional disclosures [Abstract]	'	'	'	'
Outstanding, beginning of period (in dollar per share)	$36.12	$0	'	'
Granted (in dollar per share)	$45.35	$36.12	'	'
Vested (in dollar per share)	$0	$0	'	'
Forfeited (in dollar per share)	$39.96	$0	'	'
Outstanding, end of period (in dollars per share)	$36.04	$36.12	'	'
Stock Option [Member]	'	'	'	'
Summarizes information about stock options outstanding [Abstract]	'	'	'	'
Minimum price of options outstanding, end of the period (in dollars per share)	$20.55	$20.55	$20.55	$20.55
Maximum price of options outstanding, end of the period (in dollars per share)	$96.42	$59.05	$59.05	$63.44
Options outstanding (in shares)	12,450,000	'	'	'
Options outstanding, weighted average remaining contractual life (in years)	'7 years	'	'	'
Options outstanding, weighted average exercise price (in dollars per share)	$35.77	'	'	'
Options exercisable (in shares)	4,835,000	'	'	'
Options exercisable, weighted average exercise price (in dollars per share)	$35.17	'	'	'
Summary of changes in options outstanding [Rollforward]	'	'	'	'
Number of options outstanding, beginning balance (in shares)	15,551,000	17,243,000	17,085,000	'
Number of options granted (in shares)	4,155,000	2,368,000	3,758,000	'
Number of options exercised (in shares)	-5,261,000	-1,137,000	-351,000	'
Number of options Forfeited and Expired (in shares)	-1,995,000	-2,923,000	-3,249,000	'
Number of options outstanding, ending balance (in shares)	12,450,000	15,551,000	17,243,000	17,085,000
Changes in options outstanding, additional disclosures [Abstract]	'	'	'	'
Weighted average exercise price per option, outstanding, beginning balance (in dollars per share)	$34.03	$35.24	$36.90	'
Weighted average exercise price per option granted (in dollars per share)	$40.31	$34.26	$31.04	'
Weighted average exercise price per option exercised (in dollars per share)	$32.91	$28.52	$28.19	'
Weighted average exercise price per option forfeited and expired (in dollars per share)	$39.27	$43.70	$39.89	'
Weighted average exercise price per option, outstanding, ending balance (in dollars per share)	$35.77	$34.03	$35.24	$36.90
Options exercisable (in shares)	4,835,000	'	'	'
Options exercisable, weighted average exercise price (in dollars per share)	$35.17	'	'	'
Weighted average remaining contractual term of options outstanding (in years)	'7 years	'	'	'
Weighted average remaining contractual term of options exercisable (in years)	'4 years 10 months 24 days	'	'	'
Aggregate intrinsic value of options outstanding	703,525,000	'	'	'
Aggregate intrinsic value of options exercisable	276,098,000	'	'	'
Exercise price range, lower range limit (in dollars per share)	$20.55	$20.55	$20.55	$20.55
Exercise price range, upper range limit (in dollars per share)	$96.42	$59.05	$59.05	$63.44
Minimum price of stock options granted during the period (in dollars per share)	$37.88	$34.04	$30	'
Maximum price of stock options granted during the period (in dollars per share)	$96.42	$38.10	$34.49	'
Minimum price of stock options exercised during the period (in dollars per share)	$35.34	$31.28	$20.55	'
Maximum price of stock options exercised during the period (in dollars per share)	$100.66	$38.45	$39.88	'
Total intrinsic value of options exercised during the period	166,200,000	8,700,000	2,500,000	'
Weighted average grant date fair value per stock option granted (in dollars per share)	$11.42	$10.04	$9.68	'
Total cash received as a result of stock option exercises	173,100,000	32,000,000	9,900,000	'
Tax benefit realized from exercise of stock options	$20,400,000	$1,800,000	$20,000	'
Minimum [Member]	'	'	'	'
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]	'	'	'	'
Vesting period for shares issued under 2007 plan	'3 years	'	'	'
Maximum [Member]	'	'	'	'
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]	'	'	'	'
Vesting period for shares issued under 2007 plan	'5 years	'	'	'
Exercise period form date of issuance for stock option grants	'10 years	'	'	'
Exercise price range 1 [Member] \| Stock Option [Member]	'	'	'	'
Summarizes information about stock options outstanding [Abstract]	'	'	'	'
Minimum price of options outstanding, end of the period (in dollars per share)	$20.55	'	'	'
Maximum price of options outstanding, end of the period (in dollars per share)	$30	'	'	'
Options outstanding (in shares)	2,364,000	'	'	'
Options outstanding, weighted average remaining contractual life (in years)	'6 years 9 months 18 days	'	'	'
Options outstanding, weighted average exercise price (in dollars per share)	$28.24	'	'	'
Options exercisable (in shares)	1,218,000	'	'	'
Options exercisable, weighted average exercise price (in dollars per share)	$26.90	'	'	'
Changes in options outstanding, additional disclosures [Abstract]	'	'	'	'
Exercise price range, lower range limit (in dollars per share)	$20.55	'	'	'
Exercise price range, upper range limit (in dollars per share)	$30	'	'	'
Exercise price range 2 [Member] \| Stock Option [Member]	'	'	'	'
Summarizes information about stock options outstanding [Abstract]	'	'	'	'
Minimum price of options outstanding, end of the period (in dollars per share)	$30.01	'	'	'
Maximum price of options outstanding, end of the period (in dollars per share)	$50	'	'	'
Options outstanding (in shares)	9,504,000	'	'	'
Options outstanding, weighted average remaining contractual life (in years)	'7 years 2 months 12 days	'	'	'
Options outstanding, weighted average exercise price (in dollars per share)	$36.49	'	'	'
Options exercisable (in shares)	3,169,000	'	'	'
Options exercisable, weighted average exercise price (in dollars per share)	$36.04	'	'	'
Changes in options outstanding, additional disclosures [Abstract]	'	'	'	'
Exercise price range, lower range limit (in dollars per share)	$30.01	'	'	'
Exercise price range, upper range limit (in dollars per share)	$50	'	'	'
Exercise price range 3 [Member] \| Stock Option [Member]	'	'	'	'
Summarizes information about stock options outstanding [Abstract]	'	'	'	'
Minimum price of options outstanding, end of the period (in dollars per share)	$50.01	'	'	'
Maximum price of options outstanding, end of the period (in dollars per share)	$96.42	'	'	'
Options outstanding (in shares)	582,000	'	'	'
Options outstanding, weighted average remaining contractual life (in years)	'4 years 3 months 18 days	'	'	'
Options outstanding, weighted average exercise price (in dollars per share)	$54.55	'	'	'
Options exercisable (in shares)	448,000	'	'	'
Options exercisable, weighted average exercise price (in dollars per share)	$51.54	'	'	'
Changes in options outstanding, additional disclosures [Abstract]	'	'	'	'
Exercise price range, lower range limit (in dollars per share)	$50.01	'	'	'
Exercise price range, upper range limit (in dollars per share)	$96.42	'	'	'

Contingencies_Details

Contingencies (Details) (USD $)	12 Months Ended
	Mar. 31, 2014
	Lawsuit
	Plantiff
	Case
	Action
	Entity
	Trial
Contingencies [Abstract]	'
Number of federal actions filed against company on behalf of individuals who purchased average wholesale prices litigation	4
Number of federal actions filed against the Company on behalf of individuals who purchased Celexa and/or Lexapro for pediatric use	3
Number of federal actions filed as putative nationwide class actions	2
Number of federal actions filed as putative California-wide class action	1
Number of action filed by plaintiffs as an amended complaint	2
Amount paid for agreement with MDL plaintiffs to settle Missouri class claims	$7,650,000
Minimum Missouri class claims for Lexapro class actions	4,215,000
Additional amount paid for agreement with MDL plaintiffs to settle Missouri class claims	2,700,000
Maximum total settlement payment	10,350,000
Number of actions filed against the company as defendant pending in the Missouri Circuit Court	2
Number of entities that brought action against the company who purchased or reimbursed certain purchases of Celexa or Lexapro	2
Number of additional plaintiffs after first amendment of complaint	6
Number of additional plaintiffs after second amendment of complaint	1
Number of product liability lawsuits filed against the Company	200
Number of active product liability lawsuits alleging Celexa or Lexapro caused or contributed to individuals committing or attempting suicide, or caused a violent event	13
Number of trial scheduled in 2014 and 2015	8
Number of active product liability lawsuits alleging Celexa or Lexapro caused various birth defects	179
Number of actions set for trial in Cole country	1
Number of actions set for trial in New Jersey	19
Number of cases pending in Orange County	1
Number of actions involve allegation for certain gastrointestinal injuries	6
Product liability coverage	140,000,000
Amount for claims self-insured retention per claim before April 1, 2014	10,000,000
Aggregate amount for claims self-insured retention before April 1, 2014	50,000,000
Amount for claims self-insured retention per claim after April 1, 2014	20,000,000
Aggregate amount for claims self-insured retention after April 1, 2014	60,000,000
Amount for claims self-insured retention per claim	10,000,000
Aggregate amount for claims self-insured retention	55,000,000
Number of putative stockholder class actions	9
Number of actions filed Delaware Court of Chancery of stockholder Litigation	4
Number of actions filed in New York State Supreme Court of Stockholder Litigation	5
Number of putative stockholder class actions of Furiex Pharmaceuticals, Inc	3
Number of Furiex putative stockholder class actions filed in Delaware Court of Chancery	2
Number of Furiex putative stockholder class actions filed in North Carolina	1
Number of years prior to the filing of the Telephone Consumer Protection Act Litigation	'4 years
Fees for each alleged violation	$500

Income_taxes_Details

Income taxes (Details) (USD $)	12 Months Ended
Income taxes (Details) (USD $)	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2012
Components of income (loss) before income tax expense [Abstract]	'	'	'
U.S.	($242,233,000)	($21,334,000)	$325,882,000
Foreign	323,801,000	-23,524,000	911,806,000
Income (loss) before income taxes	81,568,000	-44,858,000	1,237,688,000
Current [Abstract]	'	'	'
U.S. federal	9,616,000	20,134,000	222,012,000
State and local	-5,087,000	-8,258,000	26,984,000
Foreign	17,583,000	10,176,000	52,452,000
Total current	22,112,000	22,052,000	301,448,000
Deferred [Abstract]	'	'	'
U.S.	-96,236,000	-33,959,000	-41,970,000
Foreign	-9,618,000	-848,000	-848,000
Total deferred	-105,854,000	-34,807,000	-42,818,000
Total	-83,742,000	-12,755,000	258,630,000
Reconciliation between provision for income taxes and expected federal income taxes at statutory rate [Abstract]	'	'	'
U.S. statutory rate (in hundredths)	35.00%	35.00%	35.00%
Effect of foreign operations (in hundredths)	-79.10%	-88.80%	-16.10%
Research credit (in hundredths)	-16.00%	46.00%	-1.00%
State and local taxes, less federal tax benefit (in hundredths)	7.70%	-16.90%	1.40%
Unrecognized tax benefit - audit settlement and statute expiration (in hundredths)	-47.90%	54.70%	0.00%
Permanent differences and other items (in hundredths)	-2.40%	-1.60%	1.60%
Total (in hundredths)	-102.70%	28.40%	20.90%
Net deferred income taxes [Abstract]	'	'	'
Inventory reserves	38,905,000	42,924,000	'
Receivable allowances and other reserves	60,795,000	37,169,000	'
Plant, property and equipment	-37,201,000	-24,302,000	'
Intangible assets	-818,867,000	-255,260,000	'
Carryforwards and credits	245,454,000	64,378,000	'
Accrued liabilities	102,263,000	65,193,000	'
Employee stock option tax benefits	36,436,000	41,726,000	'
Other (includes reserve for legal contingencies)	24,226,000	21,169,000	'
Gross deferred taxes	-347,989,000	-7,003,000	'
Valuation allowance	-118,488,000	-9,787,000	'
Deferred taxes, net	-466,477,000	-16,790,000	'
Undistributed earnings of foreign subsidiaries	7,800,000,000	'	'
Number of months on outcome of IRS review	'12 months	'	'
Unrecognized tax benefits that would impact effective tax rate	406,400,000	'	'
Reconciliation of beginning and ending amount of unrecognized tax benefits [Roll Forward]	'	'	'
Balance at beginning of period	492,088,000	498,292,000	'
Additions related to prior year positions	18,000,000	2,011,000	'
Reductions related to prior year positions	0	-1,630,000	'
Reduction related to audit settlement	-73,048,000	-7,806,000	'
Reduction related to statute expiration	-14,264,000	-11,500,000	'
Additions related to current year positions	9,694,000	12,721,000	'
Other	4,572,000	0	'
Balance at ending of period	437,042,000	492,088,000	498,292,000
Amount of tax interest and penalties	16,500,000	14,800,000	'
Amount of accrued interest related to unrecognized tax benefits	$51,700,000	$75,200,000	'
Number of months that unrecognized tax benefits is anticipated will not change	'12 months	'	'

Quarterly_financial_data_unaud2

Quarterly financial data (unaudited) (Details) (USD $)	3 Months Ended								12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2012
Quarterly financial data (unaudited) [Abstract]	'	'	'	'	'	'	'	'	'	'	'
Net sales	$1,048,280	$846,784	$811,429	$796,853	$783,186	$677,967	$692,017	$751,766	$3,503,346	$2,904,936	$4,392,548
Gross profit	842,991	696,126	683,736	663,404	636,000	562,970	596,571	649,378	2,886,257	2,444,919	3,549,675
Net income (loss)	$54,084	$17,961	$69,987	$23,278	$45,443	($153,608)	$20,777	$55,285	$165,310	($32,103)	$979,058
Diluted earnings (loss) per share (in dollars per share)	$0.20	$0.07	$0.26	$0.09	$0.17	($0.58)	$0.08	$0.21	$0.61	($0.12)	$3.57

License_and_collaboration_agre2

License and collaboration agreements (Details) (USD $)

3 Months Ended

12 Months Ended

Mar. 31, 2014

Dec. 31, 2013

Sep. 30, 2013

Jun. 30, 2013

Mar. 31, 2013

Dec. 31, 2012

Sep. 30, 2012

Jun. 30, 2012

Mar. 31, 2014

Mar. 31, 2013

Mar. 31, 2012

Mar. 31, 2014

Jan. 10, 2014

Mar. 31, 2014

Mar. 31, 2013

Mar. 31, 2012

Mar. 31, 2014

Saphris [Member]

Fetzima [Member]

Trevena [Member]

Ironwood [Member]

Almirall, S.A. [Member]

moksha8 [Member]

Preferred Stock [Member]

Common Stock [Member]

Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]

Agreement to purchase exclusive rights

$76,000,000

$155,000,000

Intangible assets

231,000,000

Marketable securities and investments

30,000,000

3,000,000

Milestone payment

30,000,000

230,000,000

2,500,000

Potential future milestone payment under collaboration agreement

100,000,000

Fair value of common stock held

26,700,000

Cumulative funding amount

101,900,000

Funding amount

19,200,000

Loan term

'7 years

Net revenue

Net sales

1,048,280,000

846,784,000

811,429,000

796,853,000

783,186,000

677,967,000

692,017,000

751,766,000

3,503,346,000

2,904,936,000

4,392,548,000

11,700,000

175,063,000

23,728,000

Cost of sales [Abstract]

Cost of sales

760,642,000

649,083,000

998,087,000

7,448,000

1,010,000

SG&A [Abstract]

Payment to/ (receipt from) Ironwood for the Commercialization pool

-5,371,000

-39,244,000

-2,425,000

R&D [Abstract]

Payment to/ (receipt from) Ironwood for the Development pool

$1,510,000

($4,368,000)

$2,884,000

Business_combinations_Details

Business combinations (Details) (USD $)

3 Months Ended

12 Months Ended

0 Months Ended

12 Months Ended

Mar. 31, 2014

Dec. 31, 2013

Sep. 30, 2013

Jun. 30, 2013

Mar. 31, 2013

Dec. 31, 2012

Sep. 30, 2012

Jun. 30, 2012

Mar. 31, 2014

Mar. 31, 2013

Mar. 31, 2012

Apr. 13, 2011

Mar. 31, 2014

Mar. 31, 2013

Jan. 31, 2014

Mar. 31, 2014

Mar. 31, 2013

Mar. 31, 2014

Jan. 31, 2014

Dec. 31, 2013

Mar. 31, 2014

Clinical Data [Member]

Aptalis [Member]

Senior Unsecured Notes [Member]

In process research and development [Member]

Product

Aptalis [Member]

Country

Business Acquisition [Line Items]

Date of business acquisition

31-Jan-14

Business acquisition through cash on hand

$1,200,000,000

Cash from a foreign subsidiary

650

Issuance of aggregate principal

1,800,000,000

1,200,000,000

Number of approved products

Number of countries approved the products

Fair values of the assets acquired, including goodwill and intangible assets, and liabilities assumed [Abstract]

Accounts receivable, net

122,077,000

Inventories, net

141,750,000

Other current assets

27,971,000

Property, plant and equipment, net

103,762,000

Intangible assets, net

2,928,800,000

Other assets

2,236,000

Accounts payable and accrued liabilities

-153,575,000

Other current liabilities

-17,936,000

Long term deferred tax liabilities

-548,768,000

Other long term liabilities

-41,734,000

Total identifiable net assets acquired

2,564,583,000

Goodwill

1,048,508,000

713,091,000

1,048,508,000

713,091,000

335,417,000

Total

2,900,000,000

Cash on hand at acquisition

112,286,000

Total cash transferred at acquisition

3,012,286,000

Definite lived intangible assets

2,900,000,000

Indefinite lived intangible assets

16,600,000

Net sales

1,048,280,000

846,784,000

811,429,000

796,853,000

783,186,000

677,967,000

692,017,000

751,766,000

3,503,346,000

2,904,936,000

4,392,548,000

108,400,000

Net loss

54,084,000

17,961,000

69,987,000

23,278,000

45,443,000

-153,608,000

20,777,000

55,285,000

165,310,000

-32,103,000

979,058,000

-24,000,000

Net income (loss) per share (in dollars per share)

$0.61

($0.12)

$3.58

($0.09)

Unaudited pro forma information [Abstract]

Net sales

4,079,156,000

3,551,193,000

Net loss

-69,023,000

-148,355,000

Basic loss per share (in dollars per share)

($0.26)

($0.56)

Diluted net loss per share (in dollars per share)

($0.26)

($0.56)

Business acquisition, cost acquired entity, description of purchase price components (in dollars per share)

$30

Amount of contingent consideration to be paid after reaching milestone per a Contingent Value Rights agreement (CVR) (in dollars per share)

Amount of future milestones to be reached or exceeded

1,300,000,000

Range of undiscounted amounts we may be required to pay under the CVR, minimum

Range of undiscounted amounts we may be required to pay under the CVR, maximum

275,000,000

Fair value of contingent consideration

25,000,000

Business combination contingent consideration change in amount adjustment

$25,200,000

Restructuring_initiative_Detai

Restructuring initiative (Details) (USD $)

6 Months Ended

12 Months Ended

6 Months Ended

3 Months Ended

12 Months Ended

Mar. 31, 2014

Dec. 31, 2013

Mar. 31, 2014

Post-Employment Benefits [Member]

Consulting Fees & Other [Member]

Rejuvenate Project [Member]

Minimum [Member]

Maximum [Member]

R&D Organization [Member]

Marketing Expenses [Member]

General and Administrative Expenses [Member]

Restructuring Cost and Reserve [Line Items]

Cost savings expected to be realized

$500,000,000

$270,000,000

$150,000,000

$80,000,000

Estimates cost savings result from reduction in headcount

110,000,000

Expected cost savings (in hundredths)

65.00%

75.00%

Estimated implementing cost

150,000,000

200,000,000

Pre-tax restructuring expenses

154,100,000

Pre-tax restructuring expenses write down at fair value

74,900,000

Post-employment benefits

16,500,000

Employee termination costs

7,300,000

Consulting and other fees

20,000,000

Restructuring Reserve

Beginning Balance as of October 1, 2013

Expenses

79,226,000

59,273,000

19,953,000

Cash Payments

-12,418,000

-2,384,000

-10,034,000

Balance

$74,104,000

$56,889,000

$9,919,000

Actavis_transaction_Details

Actavis transaction (Details) (USD $)	12 Months Ended
Actavis transaction (Details) (USD $)	Mar. 31, 2014
Merger [Line Items]	'
Termination period from the date of merger agreement	'6 months
Extended termination period	'4 months
Mixed Election Consideration [Member]	'
Merger [Line Items]	'
Cash consideration per share (in dollars per share)	26.04
Number of ordinary shares issuable per share (in shares)	0.3306
Cash Election Consideration [Member]	'
Merger [Line Items]	'
Cash consideration per share (in dollars per share)	86.81
Stock Election Consideration [Member]	'
Merger [Line Items]	'
Number of ordinary shares issuable per share (in shares)	0.4723

Subsequent_events_Details

Subsequent events (Details) (Subsequent Event [Member], Furiex Pharmaceuticals, Inc [Member], USD $)	0 Months Ended	12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Apr. 28, 2014	Mar. 31, 2014
Subsequent Event [Member] \| Furiex Pharmaceuticals, Inc [Member]	'	'
Subsequent Event [Line Items]	'	'
Date of definitive agreement	'	28-Apr-14
Acquiring costs	$1,100,000	'
Maximum contingent value rights (in dollars per share)	$30	'

SCHEDULE_II_VALUATION_AND_QUAL1

SCHEDULE II - VALUATION AND QUALIFYING ACCOUNTS (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014		Mar. 31, 2013		Mar. 31, 2012
Allowance for Doubtful Accounts [Member]	'		'		'
Movement in Valuation Allowances and Reserves [Roll Forward]	'		'		'
Balance at beginning of period	$2,003		$2,290		$2,298
Acquired	0	[1]	0	[1]	0	[1]
Additions	30		27		49
Deductions	2	[2]	314	[2]	57	[2]
Balance at end of period	2,031		2,003		2,290
Allowance for Cash Discounts [Member]	'		'		'
Movement in Valuation Allowances and Reserves [Roll Forward]	'		'		'
Balance at beginning of period	9,241		8,156		13,985
Acquired	1,461	[1]	0	[1]	0	[1]
Additions	93,227		73,430		107,892
Deductions	92,302	[3]	72,345	[3]	113,721	[3]
Balance at end of period	11,627		9,241		8,156
Inventory Reserve [Member]	'		'		'
Movement in Valuation Allowances and Reserves [Roll Forward]	'		'		'
Balance at beginning of period	18,441		23,785		16,743
Acquired	0	[1]	0	[1]	0	[1]
Additions	17,002		1,000		8,042
Deductions	5,967	[2]	6,344	[2]	1,000	[2]
Balance at end of period	$29,476		$18,441		$23,785

[1]	Represents balance acquired as part of Aptalis acquisition.
[2]	Represents actual amounts written off.
[3]	Represents cash discounts given.