BioMarin Pharmaceutical (BMRN) 10-Q 2 Nov 15 2015 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2015	Oct. 23, 2015
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2015
Document Fiscal Year Focus	2,015
Document Fiscal Period Focus	Q3
Trading Symbol	BMRN
Entity Registrant Name	BIOMARIN PHARMACEUTICAL INC
Entity Central Index Key	1,048,477
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Common Stock Shares Outstanding		161,251,715

CONDENSED CONSOLIDATED BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014	[1]
Current assets:
Cash and cash equivalents	$ 376,346	$ 875,486
Short-term investments	241,984	69,706
Accounts receivable, net (allowance for doubtful accounts: $80 and $490, at September 30, 2015 and December 31, 2014, respectively)	148,949	144,472
Inventory	262,100	199,452
Current deferred tax assets	30,880	31,203
Other current assets	115,330	111,835
Total current assets	1,175,589	1,432,154
Noncurrent assets:
Long-term investments	514,381	97,856
Property, plant and equipment, net	604,513	523,516
Intangible assets, net	920,943	156,578
Goodwill	202,392	54,258
Long-term deferred tax assets	146,245	159,771
Other assets	60,790	66,320
Total assets	3,624,853	2,490,453
Current liabilities:
Accounts payable and accrued liabilities	296,200	231,844
Short-term contingent acquisition consideration payable	94,291	3,895
Total current liabilities	390,491	235,739
Noncurrent liabilities:
Long-term convertible debt	667,793	657,976
Long-term contingent acquisition consideration payable	34,874	38,767
Long-term deferred tax liabilities	193,202
Other long-term liabilities	45,853	30,077
Total liabilities	1,332,213	962,559
Stockholders’ equity:
Common stock, $0.001 par value: 250,000,000 shares authorized at September 30, 2015 and December 31, 2014: 161,226,410 and 149,093,647 shares issued and outstanding at September 30, 2015 and December 31, 2014, respectively	162	149
Additional paid-in capital	3,371,377	2,359,744
Company common stock held by Nonqualified Deferred Compensation Plan	(13,897)	(9,695)
Accumulated other comprehensive income	25,184	27,466
Accumulated deficit	(1,090,186)	(849,770)
Total stockholders’ equity	2,292,640	1,527,894
Total liabilities and stockholders’ equity	$ 3,624,853	$ 2,490,453
[1]	December 31, 2014 balances were derived from the audited Consolidated Financial Statements included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2014, filed with the Securities and Exchange Commission (the SEC) on March 2, 2015.

CONDENSED CONSOLIDATED BALANCE3

CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014	[1]
Statement Of Financial Position [Abstract]
Allowance for doubtful accounts	$ 80	$ 490
Common stock, par value	$ 0.001	$ 0.001
Common stock, shares authorized	250,000,000	250,000,000
Common stock, shares issued	161,226,410	149,093,647
Common stock, shares outstanding	161,226,410	149,093,647
[1]	December 31, 2014 balances were derived from the audited Consolidated Financial Statements included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2014, filed with the Securities and Exchange Commission (the SEC) on March 2, 2015.

CONDENSED CONSOLIDATED STATEMEN

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
REVENUES:
Net product revenues	$ 207,767	$ 173,416	$ 658,102	$ 510,664
Collaborative agreement revenues	131	353	849	1,274
Royalty, license and other revenues	1,006	2,780	3,008	7,278
Total revenues	208,904	176,549	661,959	519,216
OPERATING EXPENSES:
Cost of sales	36,719	29,920	109,410	83,946
Research and development	158,713	125,686	458,688	319,476
Selling, general and administrative	94,044	74,604	288,364	202,388
Intangible asset amortization and contingent consideration	1,301	2,636	17,518	15,041
Gain on sale of intangible asset		(67,500)		(67,500)
Total operating expenses	290,777	165,346	873,980	553,351
INCOME (LOSS) FROM OPERATIONS	(81,873)	11,203	(212,021)	(34,135)
Equity in the loss of BioMarin/Genzyme LLC	(186)	(225)	(539)	(1,102)
Interest income	1,344	1,435	3,050	4,293
Interest expense	(9,447)	(9,118)	(28,911)	(27,445)
Debt conversion expense			(163)	(674)
Other expense	(281)	(74)	(9,105)	(68)
INCOME (LOSS) BEFORE INCOME TAXES	(90,443)	3,221	(247,689)	(59,131)
Provision for (benefit from) income taxes	483	(4,224)	(7,273)	5,041
NET INCOME (LOSS)	$ (90,926)	$ 7,445	$ (240,416)	$ (64,172)
NET INCOME (LOSS) PER SHARE, BASIC	$ (0.57)	$ 0.05	$ (1.51)	$ (0.44)
NET INCOME (LOSS) PER SHARE, DILUTED	$ (0.60)	$ 0.05	$ (1.51)	$ (0.44)
Weighted average common shares outstanding, basic	160,886	147,016	159,647	145,724
Weighted average common shares outstanding, diluted	161,134	159,304	159,647	145,724
COMPREHENSIVE INCOME (LOSS)	$ (98,203)	$ 16,693	$ (242,698)	$ (50,001)

CONDENSED CONSOLIDATED STATEME5

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2015		Sep. 30, 2014
CASH FLOWS FROM OPERATING ACTIVITIES:
Net loss	$ (240,416)		$ (64,172)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	45,306		39,905
Non-cash interest expense	21,243		20,305
Accretion of discount on investments	1,616		5,748
Stock-based compensation	84,465		55,251
Gain on sale of intangible asset			(67,500)
Gain on termination of lease			(8,893)
Gain on sale of equity investment	(3,022)
Impairment of assets	12,802
Deferred income taxes	14,629		(12,373)
Excess tax benefit from stock option exercises	(463)		(205)
Unrealized foreign exchange (gain) loss on forward contracts	(16,491)		2,354
Non-cash changes in the fair value of contingent acquisition consideration payable	15,101		11,202
Other	1,059		2,136
Changes in operating assets and liabilities:
Accounts receivable, net	146		(3,482)
Inventory	(61,980)		(41,114)
Other current assets	(27,970)		(9,783)
Other assets	(1,391)		(6,708)
Accounts payable and accrued liabilities	924		30,930
Other long-term liabilities	790		(116)
Net cash used in operating activities	(153,652)		(46,515)
CASH FLOWS FROM INVESTING ACTIVITIES:
Purchases of property, plant and equipment	(123,844)		(89,295)
Funds held in escrow for the purchase of real property	(12,500)
Maturities and sales of investments	261,786		207,476
Purchase of available-for-sale investments	(842,873)		(448,938)
Proceeds from sale of intangible asset			67,500
Purchase of promissory note	(3,326)
Business acquisitions, net of cash acquired	(538,392)
Other			(3,100)
Net cash used in investing activities	(1,259,149)		(266,357)
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from exercises of stock options and Employee Stock Purchase Plan (the ESPP)	51,515		37,635
Taxes paid related to net share settlement of equity awards	(21,968)		(7,246)
Proceeds from public offering of common stock, net	888,257		117,464
Excess tax benefit from stock option exercises	463		205
Payment of contingent acquisition consideration payable			(4,691)
Other	(2,062)		(691)
Net cash provided by financing activities	916,205		142,676
Effect of exchange rate changes on cash	(2,544)		(580)
NET INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS	(499,140)		(170,776)
Cash and cash equivalents:
Beginning of period	875,486	[1]	568,781
End of period	376,346		398,005
SUPPLEMENTAL CASH FLOW DISCLOSURES:
Cash paid for interest, net of interest capitalized into fixed assets	4,979		4,759
Cash paid for income taxes	15,377		22,378
Stock-based compensation capitalized into inventory	8,271		5,663
Depreciation capitalized into inventory	11,005		7,989
SUPPLEMENTAL CASH FLOW DISCLOSURES FROM INVESTING AND FINANCING ACTIVITIES:
Decrease in accounts payable and accrued liabilities related to fixed assets	(11,386)		(2,762)
Conversion of convertible debt	$ 8,957		16,482
Release of escrow balance for purchase of San Rafael Corporate Center			$ 116,500
[1]	December 31, 2014 balances were derived from the audited Consolidated Financial Statements included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2014, filed with the Securities and Exchange Commission (the SEC) on March 2, 2015.

NATURE OF OPERATIONS AND BUSINE

NATURE OF OPERATIONS AND BUSINESS RISKS	9 Months Ended
	Sep. 30, 2015
Accounting Policies [Abstract]
NATURE OF OPERATIONS AND BUSINESS RISKS	(1) NATURE OF OPERATIONS AND BUSINESS RISKS BioMarin Pharmaceutical Inc. (the Company or BioMarin), a Delaware corporation, develops and commercializes innovative biopharmaceuticals for serious diseases and medical conditions. BioMarin selects product candidates for diseases and conditions that represent a significant unmet medical need, have well-understood biology and provide an opportunity to be first-to-market or offer a significant benefit over existing products. The Company’s product portfolio is comprised of five approved products and multiple clinical and pre-clinical product candidates. The Company’s approved products are Vimizim (elosulfase alfa), Naglazyme (galsulfase), Kuvan (sapropterin dihydrochloride), Aldurazyme (laronidase) and Firdapse (amifampridine phosphate). The Company expects to continue to finance future cash needs that exceed its operating activities primarily through its current cash, cash equivalents, short-term and long-term investments, and to the extent necessary, through proceeds from equity or debt financings, loans and collaborative agreements with corporate partners. If the Company elects to increase its spending on development programs significantly above current long-term plans or enters into potential licenses and other acquisitions of complementary technologies, products or companies, the Company may need additional capital. The Company is subject to a number of risks, including: the financial performance of Vimizim, Naglazyme, Kuvan, Aldurazyme and Firdapse; the potential need for additional financings; the Company’s ability to successfully commercialize its approved product candidates; the uncertainty of the Company’s research and development (R&D) efforts resulting in future successful commercial products; the Company’s ability to successfully obtain regulatory approval for new products; significant competition from larger organizations; reliance on the proprietary technology of others; dependence on key personnel; uncertain patent protection; dependence on corporate partners and collaborators; and possible restrictions on reimbursement from governmental agencies and healthcare organizations, as well as other changes in the health care industry.

BASIS OF PRESENTATION

BASIS OF PRESENTATION	9 Months Ended
	Sep. 30, 2015
Accounting Policies [Abstract]
BASIS OF PRESENTATION	(2) BASIS OF PRESENTATION The accompanying Condensed Consolidated Financial Statements have been prepared pursuant to the rules and regulations of the SEC for Quarterly Reports on Form 10-Q and do not include all of the information and note disclosures required by U.S. generally accepted accounting principles (U.S. GAAP) for complete financial statements, although the Company believes that the disclosures herein are adequate to ensure that the information presented is not misleading. The Condensed Consolidated Financial Statements should therefore be read in conjunction with the Consolidated Financial Statements and Notes thereto for the fiscal year ended December 31, 2014 included in the Company’s Annual Report on Form 10-K. The accompanying Condensed Consolidated Financial Statements have been prepared in accordance with U.S. GAAP, which requires management to make estimates and assumptions that affect amounts reported in the Condensed Consolidated Financial Statements and accompanying disclosures. Although these estimates are based on management’s best knowledge of current events and actions that the Company may undertake in the future, actual results may be different from those estimates. The Condensed Consolidated Financial Statements reflect all adjustments of a normal, recurring nature that are, in the opinion of management, necessary for a fair presentation of results for these interim periods. The results of operations for the three and nine months ended September 30, 2015 are not necessarily indicative of the results that may be expected for the fiscal year ending December 31, 2015. The Company has evaluated events and transactions subsequent to the balance sheet date. Based on this evaluation, the Company is not aware of any events or transactions that occurred subsequent to the balance sheet date but prior to filing this Quarterly Report on Form 10-Q that would require recognition or disclosure in the Condensed Consolidated Financial Statements, except for the transactions disclosed in Note 21.

SIGNIFICANT ACCOUNTING POLICIES

SIGNIFICANT ACCOUNTING POLICIES	9 Months Ended
	Sep. 30, 2015
Accounting Policies [Abstract]
SIGNIFICANT ACCOUNTING POLICIES	(3) SIGNIFICANT ACCOUNTING POLICIES There have been no material changes to the Company’s significant accounting policies during the nine months ended September 30, 2015, as compared to the significant accounting policies disclosed in Note 3 of the Consolidated Financial Statements in the Company’s Annual Report on Form 10-K for the year ended December 31, 2014. Reclassifications Certain items in the Company’s prior year Condensed Consolidated Financial Statements have been reclassified to conform to the current presentation.

RECENT ACCOUNTING PRONOUNCEMENT

RECENT ACCOUNTING PRONOUNCEMENTS	9 Months Ended
	Sep. 30, 2015
Accounting Changes And Error Corrections [Abstract]
RECENT ACCOUNTING PRONOUNCEMENTS	(4) RECENT ACCOUNTING PRONOUNCEMENTS Except as described below, there have been no new accounting pronouncements or changes to accounting pronouncements during the nine months ended September 30, 2015, as compared to the recent accounting pronouncements described in Note 4 of the Company’s Annual Report on Form 10-K for the year-ended December 31, 2014, that are of significance or potential significance to the Company. In April 2015, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) No. ASU 2015-03, Interest–Imputation of Interest (Subtopic 835-30) In July 2015, the FASB deferred the effective date for ASU No. 2014-09 (ASU 2014-09), Revenue from Contracts with Customers, Revenue Recognition (Topic 605) In July 2015, the FASB issued ASU No. 2015-11, Inventory In September 2015, the FASB issued ASU No. 2015-16, Simplifying the Accounting for Measurement-Period Adjustments

ACQUISITIONS

ACQUISITIONS	9 Months Ended
	Sep. 30, 2015
Business Combinations [Abstract]
ACQUISITIONS	(5) ACQUISITIONS Prosensa Holding N.V. On January 29, 2015, the Company completed the acquisition of Prosensa Holding N.V. (Prosensa), a public limited liability company organized under the laws of the Netherlands, for a total purchase price of $751.5 million. In connection with the acquisition of Prosensa, the Company recognized transaction costs of $9.7 million, of which $2.7 million and $7.0 million, respectively, was recognized in the year ended December 31, 2014 and the nine months ended September 30, 2015. Prosens a was an innovative biotechnology company engaged in the discovery and development of ribonucleic acid (RNA)-modulating therapeutics for the treatment of genetic disorders. Prosensa’s primary focus was on rare neuromuscular and neurodegenerative disorders with a large unmet medical need, including subsets of patients with Duchenne muscular dystrophy (DMD), myotonic dystrophy and Huntington’s disease. Prosensa’s clinical portfolio of RNA-based product candidates was focused on the treatment of DMD. Each of Prosensa’s DMD compounds has been granted orphan drug status in the United States (the U.S.) and the European Union (the EU). Prosensa’s lead product, Kyndrisa formerly referred to as drisapersen, is currently under review as part of a rolling new drug application (NDA) with the Food and Drug Administration (the FDA). On April 27, 2015, the Company announced the completion of the rolling submission of the NDA to the FDA. On June 8, 2015, the Company announced the submission of a marketing authorization application (MAA) for Kyndrisa with the European Medicines Agency (the EMA). In connection with its acquisition of Prosensa, the Company made cash payments totaling $680.1 million, which were comprised of $620.7 million for approximately 96.8% of Prosensa’s ordinary shares (the Prosensa Shares), $38.6 million for the options that vested pursuant to the Company’s tender offer for the Prosensa Shares and $20.8 million to the remaining Prosensa shareholders that did not tender their shares under the tender offer. Additionally, for each Prosensa Share, the Company issued one non-transferable contingent value right (the CVR), which represents the contractual right to receive a cash payment of up to $4.14 per Prosensa Share, or an aggregate of approximately $160.0 million (undiscounted), upon the achievement of certain product approval milestones. The fair value of the CVRs and acquired in-process research and development (IPR&D) on the acquisition date was $71.4 million and $772.8 million, respectively. The acquisition date fair value of the CVRs and IPR&D was estimated by applying a probability-based income approach utilizing an appropriate discount rate. Key assumptions include a discount rate and various probability factors. See Note 15 to these Condensed Consolidated Financial Statements for additional discussion regarding fair value measurements of the CVRs, which is included in contingent acquisition consideration payable. The following table presents the allocation of the purchase consideration for the Prosensa acquisition, including the CVRs, based on fair value. Cash and cash equivalents $ 141,669 Trade accounts receivable 3,086 Other current assets 1,537 Property, plant and equipment 2,683 Intangible assets 497 Other assets 104 Acquired IPR&D 772,808 Total identifiable assets acquired 922,384 Accounts payable and accrued expenses (68,799 ) Debt assumed (57,053 ) Deferred tax liability (193,202 ) Total liabilities assumed (319,054 ) Net identifiable assets acquired 603,330 Goodwill 148,134 Net assets acquired $ 751,464 A substantial portion of the assets acquired consisted of IPR&D related to Prosensa’s product candidates Kyndrisa and exons PRO 044 and PRO 045, which are considered to be indefinite-lived assets until completion or abandonment of the associated research and development (R&D) efforts. The Company determined that the estimated acquisition-date fair value of the intangible assets related to Kyndrisa and Prosensa’s other primary product candidates, PRO 044 and PRO 045, was $731.8 million, $16.9 million and $24.1 million, respectively. The deferred tax liability relates to the tax impact of future amortization or possible impairments associated with the identified intangible assets acquired, which are not deductible for tax purposes. Prosensa’s results of operations prior to and since the acquisition date are insignificant to the Company’s Condensed Consolidated Financial Statements. See Note 10 to these Condensed Consolidated Financial Statements for further discussion of the indefinite-lived intangible assets. San Rafael Corporate Center In March 2014, the Company completed the acquisition of the real estate commonly known as the San Rafael Corporate Center (SRCC), located in San Rafael, California. SRCC is a multi-building, commercial property where, prior to the acquisition, the Company was leasing a certain portion of the space for its headquarters and related operating activities. The purpose of this acquisition is to allow for future expansion of the Company’s corporate headquarters to accommodate anticipated headcount growth. The acquisition of SRCC has been accounted for as a business combination because the building and the in-place leases met the definition of a business in Accounting Standards Codification 805 (ASC 805), Business Combinations. The following table summarizes the estimated fair values of assets acquired as of the date of acquisition: Estimated Fair Value Estimated Useful Lives Building and improvements $ 94,414 50 years Land 14,565 Land improvements 3,616 10 years Lease intangible assets 3,905 Remaining lease terms Total identifiable net assets $ 116,500 The fair values assigned to tangible and identifiable intangible assets acquired are based on management’s estimates and assumptions using the information that was available as of the date of the acquisition. The Company believes that the information provides a reasonable basis for estimating the fair values of assets acquired. The following table sets forth the fair value of the components of the identifiable lease intangible assets acquired by asset class as of the date of acquisition: Above market leases $ 351 In-place leases 3,554 Total lease intangible assets subject to amortization $ 3,905 The value of any lease intangible assets (such as in-place and above-market leases) is estimated to be equal to the property owners’ avoidance of costs necessary to release the property for a lease term equal to the remaining primary in-place lease term and the value of investment-grade tenancy, which is derived by estimating, based on a review of the market, the cost to be borne by a property owner to replicate a market lease for the remaining in-place term. These costs consist of: (i) rent lost during downtime (e.g., assumed periods of vacancy), (ii) estimated expenses that would be incurred by the property owner during periods of vacancy, (iii) rent concessions (e.g., free rent), (iv) leasing commissions and (v) tenant improvement allowances. The Company determined these values using management’s estimates along with third-party appraisals. The Company will amortize the capitalized value of lease intangible assets over the remaining lives of the underlying leases. Lease intangible assets are amortized as a reduction in (addition to) third-party tenant revenue, which is included in Royalty, License and Other Revenues on the Company’s Condensed Consolidated Statements of Comprehensive Income (Loss) for the three and nine months ended September 30, 2015 and 2014 . The amount of third-party tenant revenue included in the Company’s Condensed Consolidated Statements of Comprehensive Income (Loss) for the three and nine months ended September 30, 2015 was $0.6 million and $2.1 million, respectively, compared to $1.3 million and $3.1 million for the three and nine months ended September 30, 2014, respectively. Amortization expense for each of the three and nine months ended September 30, 2015 and 2014 were $0.3 million and $1.0 million, respectively. The amount of net income/loss from third-party tenants for each of the three and nine months ended September 30, 2015 and 2014 was insignificant to the Company’s Condensed Consolidated Statement of Comprehensive Income (Loss). SRCC’s results of operations prior to the acquisition were insignificant to the Company’s Condensed Consolidated Financial Statements. Included in Selling, General and Administrative (SG&A) expenses during the nine months ended September 30, 2014 are transaction costs incurred in connection with the acquisition of SRCC of $0.3 million. The Company recognized a gain of $8.8 million in the nine months ended September 30, 2014 due to the early termination of the Company’s pre-existing lease and the realization of the remaining balance in deferred rent and the reversal of the related asset retirement obligation upon acquisition of SRCC. $2.7 million and $6.1 million of the gain were included in SG&A and R&D expenses, respectively, which is consistent with the Company’s allocation practices for facility costs for this previously leased space.

STOCKHOLDERS' EQUITY

STOCKHOLDERS' EQUITY	9 Months Ended
	Sep. 30, 2015
Equity [Abstract]
STOCKHOLDERS' EQUITY	(6) STOCKHOLDERS’ EQUITY In January 2015, the Company sold 9,775,000 shares of its common stock at a price of $93.25 per share in an underwritten public offering pursuant to an effective registration statement previously filed with the SEC. The Company received net proceeds of approximately $888.3 million from this public offering after underwriter’s discount and offering costs.

NET INCOME (LOSS) PER COMMON SH

NET INCOME (LOSS) PER COMMON SHARE	9 Months Ended
	Sep. 30, 2015
Earnings Per Share [Abstract]
NET INCOME (LOSS) PER COMMON SHARE	(7) NET INCOME (LOSS) PER COMMON SHARE Potentially issuable shares of common stock include shares issuable upon the exercise of outstanding employee stock option awards, common stock issuable under the Company’s Amended and Restated 2006 Employee Stock Purchase Plan (the ESPP), unvested restricted stock units (RSUs), common stock held by the Company’s Nonqualified Deferred Compensation Plan (the NQDC) and contingent issuances of common stock related to convertible debt. The following table sets forth the computation of basic and diluted earnings per common share (in thousands of common shares): Three Months Ended September 30, Nine Months Ended September 30, 2015 2014 2015 2014 Numerator: Net income (loss), basic $ (90,926 ) $ 7,445 $ (240,416 ) $ (64,172 ) Interest expense related to the 2017 Notes — 156 — — Gain on common stock held by the NQDC (4,980 ) — — — Net income (loss), diluted $ (95,906 ) $ 7,601 $ (240,416 ) $ (64,172 ) Denominator: Weighted-average common shares outstanding, basic 160,886 147,016 159,647 145,724 Effect of dilutive securities: Options to purchase common stock — 9,275 — — Common stock issuable under the 2017 Notes — 2,238 — — Unvested RSUs — 642 — — Potentially issuable common stock of ESPP purchases — 133 — — Common shares held by the NQDC 248 — — — Weighted-average common shares outstanding, diluted 161,134 159,304 159,647 145,724 Net income (loss) per common share, basic $ (0.57 ) $ 0.05 $ (1.51 ) $ (0.44 ) Net income (loss) per common share, diluted $ (0.60 ) $ 0.05 $ (1.51 ) $ (0.44 ) In addition to the equity instruments included in the table above, the table below presents potential shares of common stock that were excluded from the computation as they were anti-dilutive using the treasury stock method (in thousands of common shares): Three Months Ended September 30, Nine Months Ended September 30, 2015 2014 2015 2014 Options to purchase common stock 10,503 3,491 10,503 12,780 Common stock issuable under the 2017 Notes 1,553 — 1,553 2,238 Common stock issuable under the 2018 and 2020 Notes 7,966 7,966 7,966 7,966 Unvested restricted stock units 1,757 559 1,633 1,216 Potentially issuable common stock for ESPP purchases 229 — 220 135 Common stock held by the NQDC — 224 248 224 Total number of potentially issuable shares 22,008 12,240 22,123 24,559 The effect of the Company’s 0.75% senior subordinated convertible notes due in 2018 (the 2018 Notes) and the Company’s 1.50% senior subordinated convertible notes due in 2020 (the 2020 Notes, and together with the 2018 Notes, the Notes) was excluded from the diluted net loss per common share since they may be settled in cash or shares at the Company’s option and the Company’s current intention is to settle up to the principal amount of the converted notes in cash and any excess conversion value (conversion spread) in shares of the Company’s common stock. As a result, during the three and nine months ended September 30, 2014 the 2018 Notes and the 2020 Notes had no effect on diluted net loss per share as the Company’s stock price did not exceed the conversion price of $94.15 per share for the Notes. Although the Company’s stock price exceeded the conversion price at September 30, 2015, the potential shares issuable under the Notes were excluded from the calculation of diluted loss per share as they were anti-dilutive using the if-converted method.

INVESTMENTS

INVESTMENTS	9 Months Ended
	Sep. 30, 2015
Investments Schedule [Abstract]
INVESTMENTS	(8) INVESTMENTS All investments were classified as available-for-sale at September 30, 2015 and December 31, 2014. The amortized cost, gross unrealized holding gains or losses, and fair value of the Company’s available-for-sale securities by major security type at September 30, 2015 and December 31, 2014 are summarized in the tables below: Amortized Cost Gross Unrealized Holding Gains Gross Unrealized Holding Losses Aggregate Fair Value at September 30, 2015 Certificates of deposit $ 57,687 $ 1 $ — $ 57,688 Corporate debt securities 413,955 216 (757 ) 413,414 Commercial paper 60,892 — — 60,892 U.S. government agency securities 223,963 278 — 224,241 Greek government-issued bonds 50 80 — 130 Total $ 756,547 $ 575 $ (757 ) $ 756,365 Amortized Cost Gross Unrealized Holding Gains Gross Unrealized Holding Losses Aggregate Fair Value at December 31, 2014 Certificates of deposit $ 72,302 $ 1 $ — $ 72,303 Corporate debt securities 95,478 — (342 ) 95,136 Greek government-issued bonds 50 73 — 123 Total $ 167,830 $ 74 $ (342 ) $ 167,562 The Company has two investments in marketable equity securities measured using quoted prices in their respective active markets that are collectively considered strategic investments. As of September 30, 2015, the fair value of the Company’s marketable equity securities was $21.4 million, which included an unrealized gain of $16.0 million. As of December 31, 2014, the fair value of the Company’s marketable equity securities was $30.8 million, which included an unrealized gain of $18.3 million. These investments are recorded in Other Assets in the Company’s Condensed Consolidated Balance Sheets. The fair values of available-for-sale securities by contractual maturity were as follows: September 30, December 31, 2015 2014 Maturing in one year or less $ 241,984 $ 69,706 Maturing after one year through five years 514,381 97,856 Total $ 756,365 $ 167,562 Impairment assessments are made at the individual security level each reporting period. When the fair value of an investment is less than its cost at the balance sheet date, a determination is made as to whether the impairment is other-than-temporary and, if it is other-than-temporary, an impairment loss is recognized in earnings equal to the difference between the investment’s amortized cost and fair value at such date. As of September 30, 2015, some of the Company’s investments were in an unrealized loss position. However, the Company has the ability and intent to hold all investments that have been in a continuous loss position until maturity or recovery, thus no other-than-temporary impairment is deemed to have occurred. See Note 15 to these Condensed Consolidated Financial Statements for additional discussion regarding the fair value of the Company’s available-for-sale securities.

GOODWILL

GOODWILL	9 Months Ended
	Sep. 30, 2015
Goodwill And Intangible Assets Disclosure [Abstract]
GOODWILL	(9) GOODWILL Goodwill is tested for impairment on an annual basis and between annual tests if the Company becomes aware of any events occurring or changes in the circumstances that would indicate a reduction in the fair value of the goodwill below its carrying amount. The following table represents the changes in goodwill for the nine months ended September 30, 2015: Balance at December 31, 2014 $ 54,258 Addition of goodwill related to the acquisition of Prosensa 148,134 Balance at September 30, 2015 $ 202,392

INTANGIBLE ASSETS

INTANGIBLE ASSETS	9 Months Ended
	Sep. 30, 2015
Goodwill And Intangible Assets Disclosure [Abstract]
INTANGIBLE ASSETS	(10) INTANGIBLE ASSETS Intangible assets consisted of the following: September 30, December 31, 2015 2014 Intangible assets: Finite-lived intangible assets $ 123,732 $ 123,365 Indefinite-lived intangible assets 812,088 74,430 Indefinite-lived intangible assets held-for-sale 35,150 — Gross intangible assets: 970,970 197,795 Less: Accumulated amortization (50,027 ) (41,217 ) Net carrying value $ 920,943 $ 156,578 Indefinite-Lived Intangible Assets IPR&D assets are considered to be indefinite-lived until the completion or abandonment of the associated R&D efforts. During the period the assets are considered indefinite-lived, they will not be amortized but will be tested for impairment on an annual basis and between annual tests if the Company becomes aware of any events occurring or changes in circumstances that would indicate a reduction in the fair value of the IPR&D assets below their respective carrying amounts. If and when development is complete, which generally occurs if and when regulatory approval to market a product is obtained, the associated assets would be deemed finite-lived and would then be amortized based on their respective estimated useful lives at that point in time. In August 2015, the Company announced it had entered into an asset purchase agreement under (the Asset Purchase Agreement) which Medivation Inc. (Medivation), would acquire worldwide rights to talazoparib. As of September 30, 2015, the carrying value of the talazoparib intangible assets were classified as held-for-sale and totaled $35.2 million, which was included in Intangible Assets, net on the Company’s Condensed Consolidated Balance Sheet. The Company completed the sale of talazoparib to Medivation on October 6, 2015. See Note 21 to these Condensed Consolidated Financial Statements for additional discussion. See Note 6 to the Consolidated Financial Statements included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2014 for additional information related to the Company’s Intangible Assets.

PROPERTY, PLANT AND EQUIPMENT

PROPERTY, PLANT AND EQUIPMENT	9 Months Ended
	Sep. 30, 2015
Property Plant And Equipment [Abstract]
PROPERTY, PLANT AND EQUIPMENT	(11) PROPERTY, PLANT AND EQUIPMENT Property, plant and equipment, net consisted of the following: September 30, December 31, 2015 2014 Leasehold improvements $ 41,364 $ 39,297 Building and improvements 354,957 335,991 Manufacturing and laboratory equipment 136,432 124,564 Computer hardware and software 106,453 97,032 Furniture and equipment 16,465 13,717 Land improvements 4,557 4,106 Land 29,358 29,358 Construction-in-progress 180,220 108,340 869,806 752,405 Less: Accumulated depreciation (265,293 ) (228,889 ) Total property, plant and equipment, net $ 604,513 $ 523,516 Construction in-process primarily includes costs related to the Company’s significant in-process projects at its campus in San Rafael, California and manufacturing plant in Shanbally, Ireland. Depreciation expense for the three and nine months ended September 30, 2015 was $12.7 million and $36.4 million, respectively, of which $3.7 million and $11.0 million, respectively, was capitalized into inventory. Depreciation expense for the three and nine months ended September 30, 2014 was $11.2 million and $31.3 million, respectively, of which $2.6 million and $8.0 million, respectively, was capitalized into inventory. Capitalized interest related to the Company’s property, plant and equipment purchases for each of the three and nine months ended September 30, 2015 and 2014 was insignificant.

SUPPLEMENTAL BALANCE SHEET INFO

SUPPLEMENTAL BALANCE SHEET INFORMATION	9 Months Ended
	Sep. 30, 2015
Organization Consolidation And Presentation Of Financial Statements [Abstract]
SUPPLEMENTAL BALANCE SHEET INFORMATION	(12) SUPPLEMENTAL BALANCE SHEET INFORMATION Inventory consisted of the following: September 30, December 31, 2015 2014 Raw materials $ 41,761 $ 22,488 Work-in-process 137,751 114,393 Finished goods 82,588 62,571 Total inventory $ 262,100 $ 199,452 Other Current Assets consisted of the following: September 30, December 31, 2015 2014 Prepaid expenses $ 73,171 $ 35,390 Short-term forward currency exchange contract assets 16,396 10,513 Promissory notes receivable, net — 46,946 Restricted investments 7,346 2,354 Convertible promissory note conversion option — 2,386 Other receivables 12,606 9,733 Other 5,811 4,513 Total other current assets $ 115,330 $ 111,835 Other Assets consisted of the following: September 30, December 31, 2015 2014 Deposits $ 19,957 $ 12,021 Deferred debt offering costs 9,259 11,763 Strategic investments 21,420 30,811 Long-term forward foreign currency exchange contract assets 3,642 5,387 Other 6,512 6,338 Total other assets $ 60,790 $ 66,320 Accounts payable and accrued liabilities consisted of the following: September 30, December 31, 2015 2014 Accounts payable and accrued operating expenses $ 162,926 $ 139,513 Accrued compensation expense 62,674 45,479 Accrued vacation expense 15,450 12,540 Accrued rebates payable 27,357 14,859 Accrued royalties payable 9,886 9,050 Value added taxes payable 6,040 5,479 Other 11,867 4,924 Total accounts payable and accrued liabilities $ 296,200 $ 231,844

CONVERTIBLE DEBT

CONVERTIBLE DEBT	9 Months Ended
	Sep. 30, 2015
Debt Disclosure [Abstract]
CONVERTIBLE DEBT	(13) CONVERTIBLE DEBT The following table summarizes information regarding the Company’s convertible debt: September 30, 2015 December 31, 2014 Convertible Notes due 2020, net of unamortized discount of $68,432 December 31, 2014, respectively $ 306,561 $ 297,955 Convertible Notes due 2018, net of unamortized discount of $45,376 and $55,537, at September 30, 2015 and December 31, 2014, respectively 329,604 319,463 Convertible Notes due 2017 31,628 40,558 Total convertible debt, net of unamortized discount $ 667,793 $ 657,976 Fair value of fixed rate convertible debt Convertible Notes due in 2020 (1) $ 503,706 $ 456,360 Convertible Notes due in 2018 (1) 488,858 442,448 Convertible Notes due in 2017 (1) 163,806 180,984 Total $ 1,156,370 $ 1,079,792 (1) The fair value of the Company’s fixed rate convertible debt is based on open market trades and is classified as Level 1 in the fair value hierarchy. Interest expense on the Company’s convertible debt was comprised of the following: Three Months Ended September 30, Nine Months Ended September 30, 2015 2014 2015 2014 Coupon interest $ 2,283 $ 2,278 $ 7,667 $ 7,140 Amortization of issuance costs 823 828 2,471 2,505 Accretion of debt discount 6,341 6,012 18,773 17,800 Total interest expense on convertible debt $ 9,447 $ 9,118 $ 28,911 $ 27,445 During the nine months ended September 30, 2015, the Company entered into separate agreements with three existing holders of its senior subordinated convertible notes due in 2017 (the 2017 Notes), pursuant to which such holders converted $8.1 million in aggregate principal amount of the 2017 Notes into 399,469 shares of the Company’s common stock. In addition to issuing the requisite number of shares of the Company’s common stock, the Company also made varying cash payments to the holders totaling $0.2 million in the aggregate, of which $0.2 million was recognized in total as Debt Conversion Expense on the Condensed Consolidated Statements of Comprehensive Income (Loss) for the nine months ended September 30, 2015. During the nine months ended September 30, 2014, the Company entered into two separate agreements with an existing holder of its 2017 Notes pursuant to which such holders converted $16.5 million in aggregate principal amount of the 2017 Notes into 809,351 shares of the Company’s common stock. In addition to issuing the requisite number of shares of the Company’s common stock, the Company also made varying cash payments to the holder totaling $0.7 million in the aggregate, of which $0.7 million was recognized in total as Debt Conversion Expense on the Company’s Condensed Consolidated Statement of Comprehensive Income (Loss) for the nine months ended September 30, 2014. See Note 13 to the Consolidated Financial Statements included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2014 for additional information related to the Company’s Convertible Debt.

DERIVATIVE INSTRUMENTS AND HEDG

DERIVATIVE INSTRUMENTS AND HEDGING STRATEGIES	9 Months Ended
	Sep. 30, 2015
Derivative Instruments And Hedging Activities Disclosure [Abstract]
DERIVATIVE INSTRUMENTS AND HEDGING STRATEGIES	(14) DERIVATIVE INSTRUMENTS AND HEDGING STRATEGIES The Company uses forward foreign currency exchange contracts to hedge certain operational exposures resulting from potential changes in foreign currency exchange rates. Such exposures result from portions of the Company’s forecasted revenues and operating expenses being denominated in currencies other than the U.S. dollar, primarily the Euro, the British Pound and the Brazilian Real. The Company designates certain of these forward foreign currency exchange contracts as hedging instruments and enters into some forward foreign currency exchange contracts that are considered to be economic hedges that are not designated as hedging instruments. Whether designated or undesignated, these forward foreign currency exchange contracts protect against the reduction in value of forecasted foreign currency cash flows resulting from product revenues, royalty revenues, operating expenses and asset or liability positions designated in currencies other than the U.S. dollar. The fair values of forward foreign currency exchange contracts are estimated using current exchange rates and interest rates, and take into consideration the current creditworthiness of the counterparties or the Company, as applicable. Information regarding the specific instruments used by the Company to hedge its exposure to foreign currency exchange rate fluctuations is provided below. See Note 15 to these Condensed Consolidated Financial Statements for additional discussion regarding the fair value of forward foreign currency exchange contracts. At September 30, 2015, the Company had 215 forward foreign currency exchange contracts outstanding to sell a total of 296.4 million Euros, 160 forward foreign currency exchange contracts outstanding to purchase 155.1 million Euros and one forward foreign currency exchange contract to sell 70.0 million Reais with expiration dates ranging from October 2015 through September 2018. These hedges were entered into in order to protect against the fluctuations in revenue and operating expenses associated with Euro-denominated cash flows. The Company has formally designated these forward foreign currency exchange contracts as cash flow hedges and expects them to be highly effective in offsetting fluctuations in revenues and operating expenses denominated in Euros related to changes in foreign currency exchange rates. The Company also enters into forward foreign currency exchange contracts that are not designated as hedges for accounting purposes. The changes in fair value of these forward foreign currency exchange contracts are included as a part of SG&A expense in the Company’s Condensed Consolidated Statements of Comprehensive Income (Loss). At September 30, 2015, the Company had one outstanding forward foreign currency exchange contract to sell 58.0 million Euros, one outstanding forward foreign currency contract to purchase 7.0 million Euros and one outstanding forward foreign currency exchange contract to sell 7.1 million British Pounds, which were not designated as hedges for accounting purposes and matured on October 30, 2015. The maximum length of time over which the Company is hedging its exposure to the reduction in value of forecasted foreign currency revenues through forward foreign currency exchange contracts is through September 2018. Over the next twelve months, the Company expects to reclassify $15.1 million from accumulated other comprehensive income to earnings as the forecasted revenue transactions occur. The fair value carrying amounts of the Company’s derivative instruments were as follows: Asset Derivatives Liability Derivatives September 30, 2015 September 30, 2015 Balance Sheet Location Fair Value Balance Sheet Location Fair Value Derivatives designated as hedging instruments: Forward foreign currency exchange contracts Other current assets $ 16,326 Accounts payable and accrued liabilities $ 2,502 Forward foreign currency exchange contracts Other assets 3,642 Other long- term liabilities 3,186 Total 19,968 5,688 Derivatives not designated as hedging instruments: Forward foreign currency exchange contracts Other current assets 70 Accounts payable and accrued liabilities 131 Other assets — Other long- term liabilities — Total 70 131 Total value of derivative contracts $ 20,038 $ 5,819 Asset Derivatives Liability Derivatives December 31, 2014 December 31, 2014 Balance Sheet Location Fair Value Balance Sheet Location Fair Value Derivatives designated as hedging instruments: Forward foreign currency exchange contracts Other current assets $ 10,206 Accounts payable and accrued liabilities $ — Forward foreign currency exchange contracts Other assets 5,387 Other long- term liabilities — Total 15,593 — Derivatives not designated as hedging instruments: Forward foreign currency exchange contracts Other current assets 307 Accounts payable and accrued liabilities 12 Total 307 12 Total value of derivative contracts $ 15,900 $ 12 The effect of the Company’s derivative instruments on the Condensed Consolidated Financial Statements for the three and nine months ended September 30, 2015 and 2014 was as follows: Forward Foreign Currency Exchange Contracts Three Months Ended September 30, Nine Months Ended September 30, 2015 2014 2015 2014 Derivatives Designated as Hedging Instruments: Net gain recognized in Other Comprehensive Income (OCI) (1) $ 3,126 $ 6,247 $ 14,191 $ 9,395 Net gain (loss) reclassified from accumulated OCI into earnings (2) 5,187 359 15,084 (662 ) Net loss recognized in net income (loss) (3) (264 ) (179 ) (404 ) (499 ) Derivatives Not Designated as Hedging Instruments: Net gain (loss) recognized in net income (loss) (4) $ (514 ) $ 4,365 $ 6,052 $ 4,861 (1) Net change in the fair value of the effective portion classified as OCI. (2) Effective portion classified as net product revenue or SG&A expense. (3) Ineffective portion and amount excluded from effectiveness testing classified as SG&A expense. (4) Classified as SG&A expense. At September 30, 2015 and December 31, 2014, accumulated other comprehensive income before taxes associated with forward foreign currency exchange contracts qualifying for hedge accounting treatment was a gain of $15.0 million and a gain of $15.9 million, respectively. The Company is exposed to counterparty credit risk on all of its derivative financial instruments. The Company has established and maintains strict counterparty credit guidelines and enters into hedges only with financial institutions that are investment grade or better to minimize the Company’s exposure to potential defaults. The Company does not require collateral to be pledged under these agreements.

FAIR VALUE MEASUREMENTS

FAIR VALUE MEASUREMENTS	9 Months Ended
	Sep. 30, 2015
Fair Value Disclosures [Abstract]
FAIR VALUE MEASUREMENTS	(15) FAIR VALUE MEASUREMENTS The Company measures certain financial assets and liabilities at fair value on a recurring basis, including available-for-sale fixed income securities and foreign currency derivatives. The tables below present the fair value of these financial assets and liabilities determined using the following input levels. Fair Value Measurements at September 30, 2015 Quoted Price in Active Markets For Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Total Assets: Cash and cash equivalents: Overnight deposits $ 277,738 $ — $ — $ 277,738 Money market instruments — 98,608 — 98,608 Total cash and cash equivalents 277,738 98,608 — 376,346 Available-for-sale securities: Short-term: Certificates of deposit — 50,138 — 50,138 Corporate debt securities — 57,446 — 57,446 Commercial paper — 60,892 — 60,892 U.S. government agency securities — 73,508 — 73,508 Long-term: Certificates of deposit — 7,550 — 7,550 Corporate debt securities — 355,968 — 355,968 U.S. government agency securities — 150,733 — 150,733 Greek government-issued bonds — 130 — 130 Total available-for-sale securities — 756,365 — 756,365 Other Current Assets: Nonqualified Deferred Compensation Plan assets — 348 — 348 Forward foreign currency exchange contract (1) — 16,396 — 16,396 Restricted investments (2) — 7,346 — 7,346 Total other current assets — 24,090 — 24,090 Other Assets: Nonqualified Deferred Compensation Plan assets — 5,989 — 5,989 Forward foreign currency exchange contract (1) — 3,642 — 3,642 Strategic investment (4) 21,420 — — 21,420 Total other assets 21,420 9,631 — 31,051 Total assets $ 299,158 $ 888,694 $ — $ 1,187,852 Liabilities: Current Liabilities: Nonqualified Deferred Compensation Plan liability $ 1,783 $ 348 $ — $ 2,131 Forward foreign currency exchange contract (1) — 2,633 — 2,633 Contingent acquisition consideration payable — — 94,291 94,291 Total current liabilities 1,783 2,981 94,291 99,055 Other long-term liabilities: Nonqualified Deferred Compensation Plan liability 24,341 5,989 — 30,330 Forward foreign currency exchange contract (1) — 3,186 — 3,186 Contingent acquisition consideration payable — — 34,874 34,874 Total other long-term liabilities 24,341 9,175 34,874 68,390 Total liabilities $ 26,124 $ 12,156 $ 129,165 $ 167,445 Fair Value Measurements at December 31, 2014 Quoted Price in Active Markets For Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Total Assets: Cash and cash equivalents: Overnight deposits $ 225,159 $ — $ — $ 225,159 Money market instruments — 650,327 — 650,327 Total cash and cash equivalents 225,159 650,327 — 875,486 Available-for-sale securities: Short-term: Certificates of deposit — 54,174 — 54,174 Corporate debt securities — 15,532 — 15,532 Long-term: Certificates of deposit — 18,129 — 18,129 Corporate debt securities — 79,604 — 79,604 Greek government-issued bonds — 123 — 123 Total available-for-sale securities — 167,562 — 167,562 Other Current Assets: Nonqualified Deferred Compensation Plan assets — 514 — 514 Forward foreign currency exchange contract (1) — 10,513 — 10,513 Restricted investments (2) — 2,354 — 2,354 Embedded derivative (3) — — 2,386 2,386 Total other current assets — 13,381 2,386 15,767 Other Assets: Nonqualified Deferred Compensation Plan assets — 5,112 — 5,112 Restricted investments (2) — 5,387 — 5,387 Strategic investment (4) 30,811 — — 30,811 Total other assets 30,811 10,499 — 41,310 Total assets $ 255,970 $ 841,769 $ 2,386 $ 1,100,125 Liabilities: Current Liabilities: Nonqualified Deferred Compensation Plan liability $ 1,790 $ 514 $ — $ 2,304 Forward foreign currency exchange contract (1) — 12 — 12 Contingent acquisition consideration payable — — 3,895 3,895 Total current liabilities 1,790 526 3,895 6,211 Other long-term liabilities: Nonqualified Deferred Compensation Plan liability 18,453 5,112 — 23,565 Contingent acquisition consideration payable — — 38,767 38,767 Total other long-term liabilities 18,453 5,112 38,767 62,332 Total liabilities $ 20,243 $ 5,638 $ 42,662 $ 68,543 (1) See Note 14 to these Condensed Consolidated Financial Statements for further information regarding the derivative instruments. (2) The restricted investments at September 30, 2015 and December 31, 2014 secure the Company’s irrevocable standby letter of credit obtained in connection with certain commercial agreements. (3) The embedded derivative at December 31, 2014 represents the fair value of the conversion feature of a promissory note that may be settled in the issuer’s underlying shares. (4) The Company has investments in marketable equity securities measured using quoted prices in an active market that are considered strategic investments. See Note 8 to these Condensed Consolidated Financial Statements for additional discussion regarding the Company’s strategic investments. There were no transfers between levels during the three and nine months ended September 30, 2015. The Company’s Level 2 securities are valued using third-party pricing sources. The pricing services utilize industry standard valuation models, including both income and market-based approaches, for which all significant inputs are observable, either directly or indirectly, to estimate fair value. These inputs include reported trades of and broker/dealer quotes on the same or similar securities, issuer credit spreads, benchmark securities, prepayment/default projections based on historical data and other observable inputs. The Company validates the prices provided by its third-party pricing services by understanding the models used, obtaining market values from other pricing sources, analyzing pricing data in certain instances and confirming those securities traded in active markets. See Note 8 to these Condensed Consolidated Financial Statements for further information regarding the Company’s financial instruments. Liabilities measured at fair value using Level 3 inputs were comprised of contingent acquisition consideration payable and asset retirement obligations. The Company’s contingent acquisition consideration payable is estimated using a probability-based income approach utilizing an appropriate discount rate. Key assumptions used by management to estimate the fair value of contingent acquisition consideration payable include estimated probabilities, the estimated timing of when a milestone may be attained and assumed discount periods and rates. Subsequent changes in the fair value of the contingent acquisition consideration payable, resulting from management’s revision of key assumptions, will be recorded in Intangible Asset Amortization and Contingent Consideration in the Company’s Condensed Consolidated Statements of Comprehensive Income (Loss). The probability-based income approach used by management to estimate the fair value of the contingent acquisition consideration is most sensitive to changes in the estimated probabilities. Contingent acquisition consideration payable at December 31, 2014 $ 42,662 Addition of contingent consideration payable related to the Prosensa acquisition (CVR) 71,402 Changes in the fair value of contingent acquisition consideration payable 15,101 Contingent acquisition consideration payable at September 30, 2015 $ 129,165 Under certain of the Company’s lease agreements, the Company is contractually obligated to return leased space to its original condition upon termination of the lease agreement. The Company records an asset retirement obligation liability and a corresponding capital asset in an amount equal to the estimated fair value of the obligation when estimable. In subsequent periods, for each such lease, the Company records Interest Expense to accrete the asset retirement obligation liability to full value and depreciates each capitalized asset retirement obligation asset, both over the term of the associated lease agreement. Asset retirement obligations at December 31, 2014 $ 3,765 Accretion expense 109 Additions 748 Payments (29 ) Asset retirement obligations at September 30, 2015 $ 4,593 The Company acquired intangible assets as a result of various business acquisitions. The estimated fair value of these long-lived assets was measured using Level 3 inputs as of the acquisition date.

STOCK-BASED COMPENSATION

STOCK-BASED COMPENSATION	9 Months Ended
	Sep. 30, 2015
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
STOCK-BASED COMPENSATION	(16) STOCK-BASED COMPENSATION The Company’s stock-based compensation plans include the Amended and Restated 2006 Share Incentive Plan (the Share Incentive Plan), the ESPP, the 2014 Inducement Plan and the 2012 Inducement Plan. The 2012 Inducement Plan expired in May 2013 and the 2014 Inducement Plan expired in June 2015. The Company’s stock-based compensation plans are administered by the Compensation Committee of the Company’s Board of Directors (the Board), which selects persons to receive awards and determines the number of shares subject to each award and the terms, conditions, performance measures and other provisions of the awards. See Note 16 to the Consolidated Financial Statements included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2014 for additional information related to these stock-based compensation plans. Determining the Fair Value of Stock Options and Stock Purchase Rights The fair value of each option award is estimated on the date of grant using the Black-Scholes valuation model and the assumptions noted in the tables below. The expected life of options is based on observed historical exercise patterns. Groups of employees that have similar historical exercise patterns were considered separately for valuation purposes, and as of September 30, 2015 the Company has identified two groups with distinctly different exercise patterns. The two groups identified are executive and non-executive employees. The executive employee group has a history of holding options for longer periods than non-executive employees. The expected volatility of stock options is based upon the weighted average of the historical volatility of the Company’s common stock and the implied volatility of traded options on the Company’s common stock for fiscal periods in which there is sufficient trading volume in options on the Company’s common stock. The risk-free interest rate is based on the implied yield on a U.S. Treasury zero-coupon issue with a remaining term equal to the expected term of the option. The dividend yield reflects that the Company has not paid any cash dividends since inception and does not intend to pay any cash dividends in the foreseeable future. The assumptions used to estimate the per share fair value of stock options granted under the 2012 Inducement Plan, the 2014 Inducement Plan and the Share Incentive Plan were as follows: Three Months Ended September 30, Nine Months Ended September 30, 2015 2014 2015 2014 Expected volatility 41 – 44% 44 – 45% 39 – 45% 44 – 45% Dividend yield 0.0% 0.0% 0.0% 0.0% Expected life 6.9 6.9 years 6.4 6.9 years Risk-free interest rate 1.9– 2.1% 2.0 – 2.2% 1.5– 2.2% 2.0 – 2.3% During the nine months ended September 30, 2015, the Company granted 718,670 options with a weighted average fair value of $56.86 per option. The Company did not issue any new stock purchase rights under the ESPP during the three months ended September 30, 2015. Restricted Stock Unit Awards with Service-Based Vesting Conditions Restricted stock units ( RSUs) are generally subject to forfeiture if employment terminates prior to the release of vesting restrictions. The Company expenses the cost of the RSUs, which is determined to be the fair market value of the shares of common stock underlying the RSUs at the date of grant, ratably over the period during which the vesting restrictions lapse. During the nine months ended September 30, 2015, the Company granted 1,098,715 RSUs with a weighted average fair market value of $120.55 per share. Restricted Stock Unit Awards with Performance and Market-Based Vesting Conditions During 2012 and 2011, p ursuant to the approval of the Board, the Company granted 860,000 RSU awards with performance and market-based vesting conditions (the 2011/2012 Base RSUs) under the Share Incentive Plan and the 2012 Inducement Plan to certain executive officers. As of September 30, 2015, the 2011/2012 Base RSUs had a weighted-average grant date fair value of $34.66. The 2011/2012 Base RSUs will vest upon the achievement of specific performance goals (the Earned RSUs). The number of RSUs that will be awarded from the Earned RSUs will be calculated by multiplying the Earned RSUs by the Total Shareholder Return multiplier which could range from 75% to 125%. Stock-based compensation expense for this award will be recognized over the remaining service period beginning in the period the Company determines the strategic performance goal or goals is probable of achievement. During the fourth quarter of 2014, management concluded that the achievement of the 2015 revenue performance goal was probable and began recognizing compensation expense related to the RSUs allocated to the revenue performance goal. During 2013, management concluded that regulatory approval of Vimizim was probable and began recognizing compensation expense related to the performance 2011/2012 Base RSUs allocated to the Vimizim performance goal. The Company recognized compensation expense of $1.5 million and $4.6 million for these awards during the three and nine months ended September 30, 2015, respectively. For the three and nine months ended September 30, 2014, the Company recognized compensation expense related to these awards of $0.7 million and $1.6 million, respectively. Restricted Stock Unit Awards with Performance Conditions On March 3, 2015, pursuant to Board approval, the Company granted 58,300 RSU awards with performance-vesting conditions (the 2015 Base RSUs) under the Share Incentive Plan to certain executive officers. The vesting of the 2015 Base RSUs under this specific grant is contingent upon the achievement of a 2015 revenue target and a three-year service period. The number of RSUs that will be awarded from the 2015 Base RSUs upon achievement of the performance condition will be calculated by multiplying the 2015 Base RSUs by a revenue multiplier (determined based on the Company’s performance against the revenue target) which could range between 80% to 120%. The maximum number of RSUs that could vest if the performance condition is achieved and a revenue multiplier of 120% is applied is 69,960. Stock-based compensation for these awards will be recognized over the service period beginning in the period the Company determines it is probable that the revenue target will be achieved. The cost of the 2015 Base RSUs was determined to be $108.36 per RSU, based on the fair value of the common stock underlying the 2015 Base RSUs on the grant date. Accordingly, because the Company’s management determined that attainment of the revenue target is probable, the Company recognized $0.5 million and $1.3 million of compensation expense related to these awards during the three and nine months ended September 30, 2015, respectively. Compensation expense included in the Company’s Condensed Consolidated Statements of Comprehensive Income (Loss) for all stock-based compensation arrangements was as follows: Three Months Ended September 30, Nine Months Ended September 30, 2015 2014 2015 2014 Cost of sales $ 1,386 $ 1,180 $ 4,484 $ 3,807 R&D 12,578 8,279 34,972 22,300 SG&A 14,794 10,545 41,503 27,452 Total stock-based compensation expense $ 28,758 $ 20,004 $ 80,959 $ 53,559 Stock-based compensation of $8.3 million and $5.7 million was capitalized into inventory, for the nine months ended September 30, 2015 and 2014, respectively. Capitalized stock-based compensation is recognized as cost of sales when the related product is sold.

COMPREHENSIVE INCOME (LOSS)

COMPREHENSIVE INCOME (LOSS)	9 Months Ended
	Sep. 30, 2015
Equity [Abstract]
COMPREHENSIVE LOSS	(17) COMPREHENSIVE INCOME (LOSS) The following table summarizes amounts reclassified out of Accumulated Other Comprehensive Income/(Loss) (AOCI) and their effect on the Company’s Condensed Consolidated Statements of Comprehensive Income (Loss) for the three and nine months ended September 30, 2015 and 2014. Amount Reclassified from AOCI Three Months Ended September 30, Nine Months Ended September 30, Consolidated Statement of Details about AOCI Components 2015 2014 2015 2014 Comprehensive Income (Loss) Classification Gains (loss) on cash flow hedges: Forward foreign currency exchange contracts $ 4,411 $ 562 $ 13,660 $ (1,035 ) Net product revenues Forward foreign currency exchange contracts 776 — 1,424 — SG&A Gain on sale of available-for-sale investment 14 — 3,036 — Other income (expense) Less income tax effect of the above 5 203 1,098 (373 ) Provision for (benefit from) income taxes $ 5,196 $ 359 $ 17,022 $ (662 ) Net income (loss) The following tables summarize changes in the accumulated balances for each component of AOCI, including current period other comprehensive income and reclassifications out of AOCI, for the three and nine months ended September 30, 2015 and 2014. Three Months Ended September 30, 2015 Before Tax Amount Tax (Expense) Benefit Net-of-Tax Amount AOCI balance at June 30, 2015 $ 41,156 $ (8,695 ) $ 32,461 Foreign currency translation adjustment — — — Unrealized gain on available-for-sale securities: Unrealized holding loss (8,158 ) 2,951 (5,207 ) Less: reclassification adjustment for gain realized in net loss 14 (5 ) 9 Net unrealized holding loss (8,172 ) 2,956 (5,216 ) Net unrealized holding gain on cash flow hedges: Unrealized holding loss 3,126 — 3,126 Less: reclassification adjustment for gain realized in net loss 5,187 — 5,187 Net unrealized holding loss (2,061 ) — (2,061 ) Other comprehensive income (10,233 ) 2,956 (7,277 ) AOCI balance at September 30, 2015 $ 30,923 $ (5,739 ) $ 25,184 Nine Months Ended September 30, 2015 Before Tax Amount Tax (Expense) Benefit Net-of-Tax Amount AOCI balance at December 31, 2014 $ 33,984 $ (6,518 ) $ 27,466 Foreign currency translation adjustment 3 — 3 Unrealized gain on available-for-sale securities: Unrealized holding gain 865 (319 ) 546 Less: reclassification adjustment for gain realized in net loss 3,036 (1,098 ) 1,938 Net unrealized holding gain (2,171 ) 779 (1,392 ) Net unrealized holding gain on cash flow hedges: Unrealized holding gain 14,191 — 14,191 Less: reclassification adjustment for gain realized in net loss 15,084 — 15,084 Net unrealized holding gain (893 ) — (893 ) Other comprehensive income (3,061 ) 779 (2,282 ) AOCI balance at September 30, 2015 $ 30,923 $ (5,739 ) $ 25,184 Three Months Ended September 30, 2014 Before Tax Amount Tax (Expense) Benefit Net-of-Tax Amount AOCI balance at June 30, 2014 $ 15,491 $ (5,550 ) $ 9,941 Foreign currency translation adjustment (3 ) — (3 ) Unrealized gain on available-for-sale securities: Unrealized holding gain 4,138 (1,493 ) 2,645 Less: reclassification adjustment for gain realized in net income — — — Net unrealized holding gain 4,138 (1,493 ) 2,645 Net unrealized holding gain on cash flow hedges: Unrealized holding gain 9,768 (3,521 ) 6,247 Less: reclassification adjustment for loss realized in net income 562 (203 ) 359 Net unrealized holding gain 10,330 (3,724 ) 6,606 Other comprehensive income 14,465 (5,217 ) 9,248 AOCI balance at September 30, 2014 $ 29,956 $ (10,767 ) $ 19,189 Nine Months Ended September 30, 2014 Before Tax Amount Tax (Expense) Benefit Net-of-Tax Amount AOCI balance at December 31, 2013 $ 7,756 $ (2,738 ) $ 5,018 Foreign currency translation adjustment (36 ) — (36 ) Unrealized gain on available-for-sale securities: Unrealized holding gain 8,580 (3,106 ) 5,474 Less: reclassification adjustment for gain realized in net loss — — — Net unrealized holding gain 8,580 (3,106 ) 5,474 Net unrealized holding gain on cash flow hedges: Unrealized holding gain 14,691 (5,296 ) 9,395 Less: reclassification adjustment for loss realized in net loss (1,035 ) 373 (662 ) Net unrealized holding gain 13,656 (4,923 ) 8,733 Other comprehensive income 22,200 (8,029 ) 14,171 AOCI balance at September 30, 2014 $ 29,956 $ (10,767 ) $ 19,189

REVENUE AND CREDIT CONCENTRATIO

REVENUE AND CREDIT CONCENTRATIONS	9 Months Ended
	Sep. 30, 2015
Risks And Uncertainties [Abstract]
REVENUE AND CREDIT CONCENTRATIONS	(18) REVENUE AND CREDIT CONCENTRATIONS Net Product Revenue— The Company considers there to be revenue concentration risks for regions where net product revenue exceeds ten percent (10%) of consolidated net product revenue. The concentration of the Company’s net product revenue within the regions below may have a material adverse effect on the Company’s revenue and results of operations if sales in the respective regions experience difficulties. The table below summarizes consolidated net product revenue concentrations based on patient location for Vimizim, Naglazyme, Kuvan and Firdapse which are sold directly by the Company and global sales of Aldurazyme which is marketed by Genzyme Corporation (Genzyme). Genzyme is the Company’s sole customer for Aldurazyme and is responsible for marketing and selling Aldurazyme to third-parties. Net product revenues from Genzyme are comprised of royalties on worldwide net Aldurazyme sales and incremental product transfer revenues. Three Months Ended September 30, Nine Months Ended September 30, 2015 2014 2015 2014 Net product revenue marketed by the Company United States 44 % 42 % 38 % 37 % Europe 21 % 22 % 20 % 19 % Latin America 12 % 8 % 19 % 15 % Rest of world 13 % 15 % 14 % 16 % Total net product revenue marketed by the Company 90 % 87 % 91 % 87 % Aldurazyme net product revenues marketed by Genzyme 10 % 13 % 9 % 13 % Total net product revenue 100 % 100 % 100 % 100 % The following table illustrates the percentage of the Company’s consolidated net product revenue attributed to the Company’s five largest customers. Three Months Ended September 30, Nine Months Ended September 30, 2015 2014 2015 2014 Customer A 15 % 17 % 14 % 15 % Customer B (1) 9 % 13 % 8 % 13 % Customer C 6 % 4 % 13 % 11 % Customer D 9 % 13 % 11 % 11 % Customer E 13 % — 5 % — Total 52 % 47 % 51 % 50 % (1) Genzyme is the Company’s sole customer for Aldurazyme and is responsible for marketing and selling Aldurazyme to third-parties. Net product revenues from Genzyme are comprised of royalties on worldwide net Aldurazyme sales and incremental product transfer revenue. On a consolidated basis, the Company’s two largest customers accounted for 31% and 17% of the September 30, 2015 accounts receivable balance, respectively, compared to December 31, 2014 when the two largest customers accounted for 42% and 18% of the accounts receivable balance, respectively. As of September 30, 2015 and December 31, 2014, accounts receivable for the Company’s largest customer balance included $23.9 million and $34.5 million, respectively, of unbilled accounts receivable related to net incremental Aldurazyme product transfers to Genzyme. The Company does not require collateral from its customers, but does perform periodic credit evaluations of its customers’ financial condition and requires immediate payment in certain circumstances. The Company is subject to credit risk from accounts receivable related to product sales. The majority of the Company’s trade accounts receivable arises from product sales in the U.S. and the EU. The Company’s product sales to government-owned or government-funded customers in certain European countries, including Italy, Spain, Portugal, Greece and Russia, are subject to payment terms that are statutorily determined. Because these customers are government-owned or government-funded, the Company may be impacted by declines in sovereign credit ratings or sovereign defaults in these countries. A significant or further decline in sovereign credit ratings or a default in these countries may decrease the likelihood that the Company will collect accounts receivable or may increase the discount rates and the length of time until receivables are collected, which could result in a negative impact to the Company’s operating results. For each of the three and nine months ended September 30, 2015, the Company’s net product revenues for these countries was 4%. Additionally, approximately 8% of the Company’s outstanding accounts receivable at September 30, 2015 related to such countries. As of September 30, 2015, the Company’s accounts receivable in certain European countries, specifically Greece, Italy, Portugal, Spain and Russia, totaled approximately $12.5 million, of which $8.1 million is current and $2.1 million is less than 30 days past due. The Company also sells its products in other countries that face economic crises and local currency devaluation. Although the Company has historically collected receivables from customers in those countries, sustained weakness or further deterioration of the local economies and currencies may cause customers in those countries to be unable to pay for the Company’s products. The Company has not historically experienced a significant level of uncollected receivables and has received continued payments from its more aged accounts. The Company believes that the allowances for doubtful accounts related to these countries is adequate based on its analysis of the specific business circumstances and expectations of collection for each of the underlying accounts in these countries.

SEGMENT INFORMATION

SEGMENT INFORMATION	9 Months Ended
	Sep. 30, 2015
Segment Reporting [Abstract]
SEGMENT INFORMATION	(19) SEGMENT INFORMATION The Company operates in one business segment, which primarily focuses on the development and commercialization of innovative biopharmaceuticals for serious diseases and medical conditions. All products are included in one segment because the majority of the Company’s products have similar economic and other characteristics, including the nature of the products and production processes, type of customers, distribution methods and regulatory environment. Three Months Ended September 30, Nine Months Ended September 30, 2015 2014 2015 2014 Net product revenue by product: Vimizim $ 65,106 $ 25,239 $ 169,608 $ 40,389 Naglazyme 54,131 67,511 243,386 245,954 Kuvan 64,219 53,438 174,501 145,578 Aldurazyme 20,509 22,553 58,991 64,727 Firdapse 3,802 4,675 11,616 14,016 Total net product revenue $ 207,767 $ 173,416 $ 658,102 $ 510,664 Net product revenue is based on patient location for Vimizim, Naglazyme, Kuvan and Firdapse and Genzyme’s headquarters for Aldurazyme. Although Genzyme sells Aldurazyme worldwide, the royalties earned by the Company on Genzyme’s net sales are included in the U.S. region, as the transactions are with Genzyme, whose headquarters are located in the U.S. The following table summarizes total revenues from external customers and collaborative partners by geographic region. Three Months Ended September 30, Nine Months Ended September 30, 2015 2014 2015 2014 Total revenues by geographic region: United States $ 112,254 $ 98,070 $ 310,209 $ 259,738 Europe 42,822 39,743 127,796 102,808 Latin America 25,588 14,292 127,147 78,116 Rest of world 28,240 24,444 96,807 78,554 Total revenues $ 208,904 $ 176,549 $ 661,959 $ 519,216

COMMITMENTS AND CONTINGENCIES

COMMITMENTS AND CONTINGENCIES	9 Months Ended
	Sep. 30, 2015
Commitments And Contingencies Disclosure [Abstract]
COMMITMENTS AND CONTINGENCIES	(20) COMMITMENTS AND CONTINGENCIES Contingencies From time to time the Company is involved in legal actions arising in the normal course of its business. The most significant of these actions are described below. The process of resolving matters through litigation or other means is inherently uncertain and it is possible that an unfavorable resolution of these matters could adversely affect the Company, its results of operations, financial condition and cash flows. The Company’s general practice is to expense legal fees as services are rendered in connection with legal matters, and to accrue for liabilities when losses are probable and reasonably estimable. Paragraph IV Notice s As previously disclosed, the Company received a paragraph IV notice letter, dated October 3, 2014, from Dr. Reddy’s Laboratories, Inc. and Dr. Reddy’s Laboratories, Ltd. (collectively, DRL), notifying the Company that DRL has filed an abbreviated new drug application (ANDA) seeking approval of a proposed generic version of Kuvan (sapropterin dihydrochloride) 100 mg oral tablets prior to the expiration of the Company’s patents listed in the FDA’s Approved Drug Products with Therapeutic Equivalence Evaluations (the Orange Book). Additionally, the Company received a paragraph IV notice letter, dated January 22, 2015, from Par Pharmaceutical, Inc. (Par), notifying the Company that Par has filed an ANDA seeking approval of a proposed generic version of Kuvan (sapropterin dihydrochloride) 100 mg oral tablets prior to the expiration of the Company’s patents listed in the Orange Book. Together with Merck & Cie, the Company filed lawsuits against both DRL and Par in the United States District Court for the District of New Jersey alleging patent infringement for the Company’s patents relating to Kuvan, triggering the automatic 30-month stay on the approval of each ANDA. In response, DRL and Par alleged, inter alia In September 2015, the Company entered into a settlement agreement with DRL that resolved the patent litigation with DRL in the United States related to Kuvan (sapropterin dihydrochloride) 100 mg oral tablets. Under the terms of the settlement, the Company will grant DRL a non-exclusive license to its Kuvan related patents to allow DRL to market a generic version of sapropterin dihydrochloride 100mg tablets in the U.S. for the indications approved for Kuvan beginning at a confidential date in the future, but which is more than five years from the settlement date, or earlier under certain circumstances. Contingent Payments As of September 30, 2015, the Company is subject to contingent payments totaling approximately $763.0 million upon achievement of certain regulatory and licensing milestones if they occur before certain dates in the future. Of this amount, $160.0 million relates to Prosensa and $22.9 million relates to programs that are no longer being developed. As of September 30, 2015, $129.2 million of the $763.0 million of contingent payments noted above is recorded on the Company’s Condensed Balances Sheets in contingent acquisition consideration payable, of which $94.3 million is expected to be paid in the next twelve months. In the normal course of business, the Company enters into various firm purchase commitments primarily related to research and development and certain inventory related items. As of September 30, 2015, these commitments for the next five years were approximately $58.9 million. These amounts primarily relate to active pharmaceutical ingredients and represent minimum purchase requirements and post-marketing commitments related to the Company’s approved products.

SUBSEQUENT EVENTS

SUBSEQUENT EVENTS	9 Months Ended
	Sep. 30, 2015
Subsequent Events [Abstract]
SUBSEQUENT EVENTS	(21) SUBSEQUENT EVENTS On October 1, 2015, the Company announced that it had entered into a definitive agreement to acquire all global rights to Kuvan and pegvaliase from Ares Trading, S.A. (Merck Serono), with the exception of Kuvan in Japan, in exchange for an upfront payment of €340.0 million and up to and additional €185.0 million if certain sales and regulatory milestones are attained. Previously, the Company had exclusive rights to Kuvan in the U.S. and Canada and pegvaliase in the U.S. and Japan. Under the terms of the agreement, the Company will have exclusive worldwide rights to Kuvan and pegvaliase with the exception of Kuvan in Japan. The closing of the Merck Serono transaction is subject to customary closing conditions, including regulatory approvals, and the Company expects to close the transaction in January 2016. On October 6, 2015, the Company completed the sale of talazoparib to Medivation. Pursuant to the Asset Purchase Agreement, Medivation paid the Company an upfront payment of $410.0 million upon the closing of the transaction. In addition, contingent upon the successful development and commercialization of talazoparib, Medivation will pay the Company milestone payments of up to $160.0 million and mid-single digit percentage royalties on net sales of talazoparib.

SIGNIFICANT ACCOUNTING POLICI27

SIGNIFICANT ACCOUNTING POLICIES (Policies)	9 Months Ended
	Sep. 30, 2015
Accounting Policies [Abstract]
Reclassifications	Reclassifications Certain items in the Company’s prior year Condensed Consolidated Financial Statements have been reclassified to conform to the current presentation.

ACQUISITIONS (Tables)

ACQUISITIONS (Tables)	9 Months Ended
	Sep. 30, 2015
Business Acquisition [Line Items]
Fair Value of Identifiable Lease Intangible Assets Acquired by Asset Class	The following table sets forth the fair value of the components of the identifiable lease intangible assets acquired by asset class as of the date of acquisition: Above market leases $ 351 In-place leases 3,554 Total lease intangible assets subject to amortization $ 3,905
Prosensa Holding N.V
Business Acquisition [Line Items]
Summary of Estimated Fair Values of Assets Acquired and Liabilities Assumed	The following table presents the allocation of the purchase consideration for the Prosensa acquisition, including the CVRs, based on fair value. Cash and cash equivalents $ 141,669 Trade accounts receivable 3,086 Other current assets 1,537 Property, plant and equipment 2,683 Intangible assets 497 Other assets 104 Acquired IPR&D 772,808 Total identifiable assets acquired 922,384 Accounts payable and accrued expenses (68,799 ) Debt assumed (57,053 ) Deferred tax liability (193,202 ) Total liabilities assumed (319,054 ) Net identifiable assets acquired 603,330 Goodwill 148,134 Net assets acquired $ 751,464
San Rafael Corporate Center
Business Acquisition [Line Items]
Summary of Estimated Fair Values of Assets Acquired and Liabilities Assumed	The following table summarizes the estimated fair values of assets acquired as of the date of acquisition: Estimated Fair Value Estimated Useful Lives Building and improvements $ 94,414 50 years Land 14,565 Land improvements 3,616 10 years Lease intangible assets 3,905 Remaining lease terms Total identifiable net assets $ 116,500

NET INCOME (LOSS) PER COMMON 29

NET INCOME (LOSS) PER COMMON SHARE (Tables)	9 Months Ended
	Sep. 30, 2015
Earnings Per Share [Abstract]
Computation of Basic and Diluted Earnings per Common Share	The following table sets forth the computation of basic and diluted earnings per common share (in thousands of common shares): Three Months Ended September 30, Nine Months Ended September 30, 2015 2014 2015 2014 Numerator: Net income (loss), basic $ (90,926 ) $ 7,445 $ (240,416 ) $ (64,172 ) Interest expense related to the 2017 Notes — 156 — — Gain on common stock held by the NQDC (4,980 ) — — — Net income (loss), diluted $ (95,906 ) $ 7,601 $ (240,416 ) $ (64,172 ) Denominator: Weighted-average common shares outstanding, basic 160,886 147,016 159,647 145,724 Effect of dilutive securities: Options to purchase common stock — 9,275 — — Common stock issuable under the 2017 Notes — 2,238 — — Unvested RSUs — 642 — — Potentially issuable common stock of ESPP purchases — 133 — — Common shares held by the NQDC 248 — — — Weighted-average common shares outstanding, diluted 161,134 159,304 159,647 145,724 Net income (loss) per common share, basic $ (0.57 ) $ 0.05 $ (1.51 ) $ (0.44 ) Net income (loss) per common share, diluted $ (0.60 ) $ 0.05 $ (1.51 ) $ (0.44 )
Schedule Of Anti-Dilutive Common Stock Excluded From Computation of Diluted Net Income (Loss) Per Share	the table below presents potential shares of common stock that were excluded from the computation as they were anti-dilutive using the treasury stock method (in thousands of common shares): Three Months Ended September 30, Nine Months Ended September 30, 2015 2014 2015 2014 Options to purchase common stock 10,503 3,491 10,503 12,780 Common stock issuable under the 2017 Notes 1,553 — 1,553 2,238 Common stock issuable under the 2018 and 2020 Notes 7,966 7,966 7,966 7,966 Unvested restricted stock units 1,757 559 1,633 1,216 Potentially issuable common stock for ESPP purchases 229 — 220 135 Common stock held by the NQDC — 224 248 224 Total number of potentially issuable shares 22,008 12,240 22,123 24,559

INVESTMENTS (Tables)

INVESTMENTS (Tables)	9 Months Ended
	Sep. 30, 2015
Investments Schedule [Abstract]
Amortized Cost, Gross Unrealized Holding Gain or Loss, and Fair Value of Available For Sale Security by Major Security type	The amortized cost, gross unrealized holding gains or losses, and fair value of the Company’s available-for-sale securities by major security type at September 30, 2015 and December 31, 2014 are summarized in the tables below: Amortized Cost Gross Unrealized Holding Gains Gross Unrealized Holding Losses Aggregate Fair Value at September 30, 2015 Certificates of deposit $ 57,687 $ 1 $ — $ 57,688 Corporate debt securities 413,955 216 (757 ) 413,414 Commercial paper 60,892 — — 60,892 U.S. government agency securities 223,963 278 — 224,241 Greek government-issued bonds 50 80 — 130 Total $ 756,547 $ 575 $ (757 ) $ 756,365 Amortized Cost Gross Unrealized Holding Gains Gross Unrealized Holding Losses Aggregate Fair Value at December 31, 2014 Certificates of deposit $ 72,302 $ 1 $ — $ 72,303 Corporate debt securities 95,478 — (342 ) 95,136 Greek government-issued bonds 50 73 — 123 Total $ 167,830 $ 74 $ (342 ) $ 167,562
Fair Values of Available-For-Sale Securities by Contractual Maturity	The fair values of available-for-sale securities by contractual maturity were as follows: September 30, December 31, 2015 2014 Maturing in one year or less $ 241,984 $ 69,706 Maturing after one year through five years 514,381 97,856 Total $ 756,365 $ 167,562

GOODWILL - SCHEDULE OF CHANGES

GOODWILL - SCHEDULE OF CHANGES IN GOODWILL (Tables)	9 Months Ended
	Sep. 30, 2015
Goodwill And Intangible Assets Disclosure [Abstract]
Schedule of Changes in Goodwill	The following table represents the changes in goodwill for the nine months ended September 30, 2015: Balance at December 31, 2014 $ 54,258 Addition of goodwill related to the acquisition of Prosensa 148,134 Balance at September 30, 2015 $ 202,392

INTANGIBLE ASSETS (Tables)

INTANGIBLE ASSETS (Tables)	9 Months Ended
	Sep. 30, 2015
Goodwill And Intangible Assets Disclosure [Abstract]
Schedule of Intangible Assets	Intangible assets consisted of the following: September 30, December 31, 2015 2014 Intangible assets: Finite-lived intangible assets $ 123,732 $ 123,365 Indefinite-lived intangible assets 812,088 74,430 Indefinite-lived intangible assets held-for-sale 35,150 — Gross intangible assets: 970,970 197,795 Less: Accumulated amortization (50,027 ) (41,217 ) Net carrying value $ 920,943 $ 156,578

PROPERTY, PLANT AND EQUIPMENT (

PROPERTY, PLANT AND EQUIPMENT (Tables)	9 Months Ended
	Sep. 30, 2015
Property Plant And Equipment [Abstract]
Schedule of Property Plant and Equipment Net	Property, plant and equipment, net consisted of the following: September 30, December 31, 2015 2014 Leasehold improvements $ 41,364 $ 39,297 Building and improvements 354,957 335,991 Manufacturing and laboratory equipment 136,432 124,564 Computer hardware and software 106,453 97,032 Furniture and equipment 16,465 13,717 Land improvements 4,557 4,106 Land 29,358 29,358 Construction-in-progress 180,220 108,340 869,806 752,405 Less: Accumulated depreciation (265,293 ) (228,889 ) Total property, plant and equipment, net $ 604,513 $ 523,516

SUPPLEMENTAL BALANCE SHEET IN34

SUPPLEMENTAL BALANCE SHEET INFORMATION (Tables)	9 Months Ended
	Sep. 30, 2015
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Schedule Of Inventory	Inventory consisted of the following: September 30, December 31, 2015 2014 Raw materials $ 41,761 $ 22,488 Work-in-process 137,751 114,393 Finished goods 82,588 62,571 Total inventory $ 262,100 $ 199,452
Schedule of Other Current Assets	Other Current Assets consisted of the following: September 30, December 31, 2015 2014 Prepaid expenses $ 73,171 $ 35,390 Short-term forward currency exchange contract assets 16,396 10,513 Promissory notes receivable, net — 46,946 Restricted investments 7,346 2,354 Convertible promissory note conversion option — 2,386 Other receivables 12,606 9,733 Other 5,811 4,513 Total other current assets $ 115,330 $ 111,835
Schedule of Other Assets	Other Assets consisted of the following: September 30, December 31, 2015 2014 Deposits $ 19,957 $ 12,021 Deferred debt offering costs 9,259 11,763 Strategic investments 21,420 30,811 Long-term forward foreign currency exchange contract assets 3,642 5,387 Other 6,512 6,338 Total other assets $ 60,790 $ 66,320
Schedule of Accounts Payable and Accrued Liabilities	Accounts payable and accrued liabilities consisted of the following: September 30, December 31, 2015 2014 Accounts payable and accrued operating expenses $ 162,926 $ 139,513 Accrued compensation expense 62,674 45,479 Accrued vacation expense 15,450 12,540 Accrued rebates payable 27,357 14,859 Accrued royalties payable 9,886 9,050 Value added taxes payable 6,040 5,479 Other 11,867 4,924 Total accounts payable and accrued liabilities $ 296,200 $ 231,844

CONVERTIBLE DEBT (Tables)

CONVERTIBLE DEBT (Tables)	9 Months Ended
	Sep. 30, 2015
Debt Disclosure [Abstract]
Summary of Convertible Debt	The following table summarizes information regarding the Company’s convertible debt: September 30, 2015 December 31, 2014 Convertible Notes due 2020, net of unamortized discount of $68,432 December 31, 2014, respectively $ 306,561 $ 297,955 Convertible Notes due 2018, net of unamortized discount of $45,376 and $55,537, at September 30, 2015 and December 31, 2014, respectively 329,604 319,463 Convertible Notes due 2017 31,628 40,558 Total convertible debt, net of unamortized discount $ 667,793 $ 657,976 Fair value of fixed rate convertible debt Convertible Notes due in 2020 (1) $ 503,706 $ 456,360 Convertible Notes due in 2018 (1) 488,858 442,448 Convertible Notes due in 2017 (1) 163,806 180,984 Total $ 1,156,370 $ 1,079,792 (1) The fair value of the Company’s fixed rate convertible debt is based on open market trades and is classified as Level 1 in the fair value hierarchy.
Summary of Convertible Debt Interest Expense	Interest expense on the Company’s convertible debt was comprised of the following: Three Months Ended September 30, Nine Months Ended September 30, 2015 2014 2015 2014 Coupon interest $ 2,283 $ 2,278 $ 7,667 $ 7,140 Amortization of issuance costs 823 828 2,471 2,505 Accretion of debt discount 6,341 6,012 18,773 17,800 Total interest expense on convertible debt $ 9,447 $ 9,118 $ 28,911 $ 27,445

DERIVATIVE INSTRUMENTS AND HE36

DERIVATIVE INSTRUMENTS AND HEDGING STRATEGIES (Tables)	9 Months Ended
	Sep. 30, 2015
Derivative Instruments And Hedging Activities Disclosure [Abstract]
Fair Value Carrying Amount of Derivative Instruments	The fair value carrying amounts of the Company’s derivative instruments were as follows: Asset Derivatives Liability Derivatives September 30, 2015 September 30, 2015 Balance Sheet Location Fair Value Balance Sheet Location Fair Value Derivatives designated as hedging instruments: Forward foreign currency exchange contracts Other current assets $ 16,326 Accounts payable and accrued liabilities $ 2,502 Forward foreign currency exchange contracts Other assets 3,642 Other long- term liabilities 3,186 Total 19,968 5,688 Derivatives not designated as hedging instruments: Forward foreign currency exchange contracts Other current assets 70 Accounts payable and accrued liabilities 131 Other assets — Other long- term liabilities — Total 70 131 Total value of derivative contracts $ 20,038 $ 5,819 Asset Derivatives Liability Derivatives December 31, 2014 December 31, 2014 Balance Sheet Location Fair Value Balance Sheet Location Fair Value Derivatives designated as hedging instruments: Forward foreign currency exchange contracts Other current assets $ 10,206 Accounts payable and accrued liabilities $ — Forward foreign currency exchange contracts Other assets 5,387 Other long- term liabilities — Total 15,593 — Derivatives not designated as hedging instruments: Forward foreign currency exchange contracts Other current assets 307 Accounts payable and accrued liabilities 12 Total 307 12 Total value of derivative contracts $ 15,900 $ 12
Effect of Derivative Instruments	The effect of the Company’s derivative instruments on the Condensed Consolidated Financial Statements for the three and nine months ended September 30, 2015 and 2014 was as follows: Forward Foreign Currency Exchange Contracts Three Months Ended September 30, Nine Months Ended September 30, 2015 2014 2015 2014 Derivatives Designated as Hedging Instruments: Net gain recognized in Other Comprehensive Income (OCI) (1) $ 3,126 $ 6,247 $ 14,191 $ 9,395 Net gain (loss) reclassified from accumulated OCI into earnings (2) 5,187 359 15,084 (662 ) Net loss recognized in net income (loss) (3) (264 ) (179 ) (404 ) (499 ) Derivatives Not Designated as Hedging Instruments: Net gain (loss) recognized in net income (loss) (4) $ (514 ) $ 4,365 $ 6,052 $ 4,861 (1) Net change in the fair value of the effective portion classified as OCI. (2) Effective portion classified as net product revenue or SG&A expense. (3) Ineffective portion and amount excluded from effectiveness testing classified as SG&A expense. (4) Classified as SG&A expense.

FAIR VALUE MEASUREMENTS (Tables

FAIR VALUE MEASUREMENTS (Tables)	9 Months Ended
	Sep. 30, 2015
Fair Value Disclosures [Abstract]
Fair Value of Financial Assets and Liabilities	The Company measures certain financial assets and liabilities at fair value on a recurring basis, including available-for-sale fixed income securities and foreign currency derivatives. The tables below present the fair value of these financial assets and liabilities determined using the following input levels. Fair Value Measurements at September 30, 2015 Quoted Price in Active Markets For Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Total Assets: Cash and cash equivalents: Overnight deposits $ 277,738 $ — $ — $ 277,738 Money market instruments — 98,608 — 98,608 Total cash and cash equivalents 277,738 98,608 — 376,346 Available-for-sale securities: Short-term: Certificates of deposit — 50,138 — 50,138 Corporate debt securities — 57,446 — 57,446 Commercial paper — 60,892 — 60,892 U.S. government agency securities — 73,508 — 73,508 Long-term: Certificates of deposit — 7,550 — 7,550 Corporate debt securities — 355,968 — 355,968 U.S. government agency securities — 150,733 — 150,733 Greek government-issued bonds — 130 — 130 Total available-for-sale securities — 756,365 — 756,365 Other Current Assets: Nonqualified Deferred Compensation Plan assets — 348 — 348 Forward foreign currency exchange contract (1) — 16,396 — 16,396 Restricted investments (2) — 7,346 — 7,346 Total other current assets — 24,090 — 24,090 Other Assets: Nonqualified Deferred Compensation Plan assets — 5,989 — 5,989 Forward foreign currency exchange contract (1) — 3,642 — 3,642 Strategic investment (4) 21,420 — — 21,420 Total other assets 21,420 9,631 — 31,051 Total assets $ 299,158 $ 888,694 $ — $ 1,187,852 Liabilities: Current Liabilities: Nonqualified Deferred Compensation Plan liability $ 1,783 $ 348 $ — $ 2,131 Forward foreign currency exchange contract (1) — 2,633 — 2,633 Contingent acquisition consideration payable — — 94,291 94,291 Total current liabilities 1,783 2,981 94,291 99,055 Other long-term liabilities: Nonqualified Deferred Compensation Plan liability 24,341 5,989 — 30,330 Forward foreign currency exchange contract (1) — 3,186 — 3,186 Contingent acquisition consideration payable — — 34,874 34,874 Total other long-term liabilities 24,341 9,175 34,874 68,390 Total liabilities $ 26,124 $ 12,156 $ 129,165 $ 167,445 Fair Value Measurements at December 31, 2014 Quoted Price in Active Markets For Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Total Assets: Cash and cash equivalents: Overnight deposits $ 225,159 $ — $ — $ 225,159 Money market instruments — 650,327 — 650,327 Total cash and cash equivalents 225,159 650,327 — 875,486 Available-for-sale securities: Short-term: Certificates of deposit — 54,174 — 54,174 Corporate debt securities — 15,532 — 15,532 Long-term: Certificates of deposit — 18,129 — 18,129 Corporate debt securities — 79,604 — 79,604 Greek government-issued bonds — 123 — 123 Total available-for-sale securities — 167,562 — 167,562 Other Current Assets: Nonqualified Deferred Compensation Plan assets — 514 — 514 Forward foreign currency exchange contract (1) — 10,513 — 10,513 Restricted investments (2) — 2,354 — 2,354 Embedded derivative (3) — — 2,386 2,386 Total other current assets — 13,381 2,386 15,767 Other Assets: Nonqualified Deferred Compensation Plan assets — 5,112 — 5,112 Restricted investments (2) — 5,387 — 5,387 Strategic investment (4) 30,811 — — 30,811 Total other assets 30,811 10,499 — 41,310 Total assets $ 255,970 $ 841,769 $ 2,386 $ 1,100,125 Liabilities: Current Liabilities: Nonqualified Deferred Compensation Plan liability $ 1,790 $ 514 $ — $ 2,304 Forward foreign currency exchange contract (1) — 12 — 12 Contingent acquisition consideration payable — — 3,895 3,895 Total current liabilities 1,790 526 3,895 6,211 Other long-term liabilities: Nonqualified Deferred Compensation Plan liability 18,453 5,112 — 23,565 Contingent acquisition consideration payable — — 38,767 38,767 Total other long-term liabilities 18,453 5,112 38,767 62,332 Total liabilities $ 20,243 $ 5,638 $ 42,662 $ 68,543 (1) See Note 14 to these Condensed Consolidated Financial Statements for further information regarding the derivative instruments. (2) The restricted investments at September 30, 2015 and December 31, 2014 secure the Company’s irrevocable standby letter of credit obtained in connection with certain commercial agreements. (3) The embedded derivative at December 31, 2014 represents the fair value of the conversion feature of a promissory note that may be settled in the issuer’s underlying shares. (4) The Company has investments in marketable equity securities measured using quoted prices in an active market that are considered strategic investments. See Note 8 to these Condensed Consolidated Financial Statements for additional discussion regarding the Company’s strategic investments.
Liabilities Measured at Fair Value Using Level 3 Inputs	Contingent acquisition consideration payable at December 31, 2014 $ 42,662 Addition of contingent consideration payable related to the Prosensa acquisition (CVR) 71,402 Changes in the fair value of contingent acquisition consideration payable 15,101 Contingent acquisition consideration payable at September 30, 2015 $ 129,165
Asset Retirement Obligation Liability and Corresponding Capital Asset	Asset retirement obligations at December 31, 2014 $ 3,765 Accretion expense 109 Additions 748 Payments (29 ) Asset retirement obligations at September 30, 2015 $ 4,593

STOCK-BASED COMPENSATION (Table

STOCK-BASED COMPENSATION (Tables)	9 Months Ended
	Sep. 30, 2015
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Stock Option Valuation Assumptions	The assumptions used to estimate the per share fair value of stock options granted under the 2012 Inducement Plan, the 2014 Inducement Plan and the Share Incentive Plan were as follows: Three Months Ended September 30, Nine Months Ended September 30, 2015 2014 2015 2014 Expected volatility 41 – 44% 44 – 45% 39 – 45% 44 – 45% Dividend yield 0.0% 0.0% 0.0% 0.0% Expected life 6.9 6.9 years 6.4 6.9 years Risk-free interest rate 1.9– 2.1% 2.0 – 2.2% 1.5– 2.2% 2.0 – 2.3%
Stock-Based Compensation Expense	Compensation expense included in the Company’s Condensed Consolidated Statements of Comprehensive Income (Loss) for all stock-based compensation arrangements was as follows: Three Months Ended September 30, Nine Months Ended September 30, 2015 2014 2015 2014 Cost of sales $ 1,386 $ 1,180 $ 4,484 $ 3,807 R&D 12,578 8,279 34,972 22,300 SG&A 14,794 10,545 41,503 27,452 Total stock-based compensation expense $ 28,758 $ 20,004 $ 80,959 $ 53,559

COMPREHENSIVE INCOME (LOSS) (Ta

COMPREHENSIVE INCOME (LOSS) (Tables)	9 Months Ended
	Sep. 30, 2015
Equity [Abstract]
Amounts Reclassified out of Accumulated Other Comprehensive Loss	The following table summarizes amounts reclassified out of Accumulated Other Comprehensive Income/(Loss) (AOCI) and their effect on the Company’s Condensed Consolidated Statements of Comprehensive Income (Loss) for the three and nine months ended September 30, 2015 and 2014. Amount Reclassified from AOCI Three Months Ended September 30, Nine Months Ended September 30, Consolidated Statement of Details about AOCI Components 2015 2014 2015 2014 Comprehensive Income (Loss) Classification Gains (loss) on cash flow hedges: Forward foreign currency exchange contracts $ 4,411 $ 562 $ 13,660 $ (1,035 ) Net product revenues Forward foreign currency exchange contracts 776 — 1,424 — SG&A Gain on sale of available-for-sale investment 14 — 3,036 — Other income (expense) Less income tax effect of the above 5 203 1,098 (373 ) Provision for (benefit from) income taxes $ 5,196 $ 359 $ 17,022 $ (662 ) Net income (loss)
Summary of Changes in Accumulated Balances of Other Comprehensive Income Loss Including Current Period Other Comprehensive Income and Reclassifications	The following tables summarize changes in the accumulated balances for each component of AOCI, including current period other comprehensive income and reclassifications out of AOCI, for the three and nine months ended September 30, 2015 and 2014. Three Months Ended September 30, 2015 Before Tax Amount Tax (Expense) Benefit Net-of-Tax Amount AOCI balance at June 30, 2015 $ 41,156 $ (8,695 ) $ 32,461 Foreign currency translation adjustment — — — Unrealized gain on available-for-sale securities: Unrealized holding loss (8,158 ) 2,951 (5,207 ) Less: reclassification adjustment for gain realized in net loss 14 (5 ) 9 Net unrealized holding loss (8,172 ) 2,956 (5,216 ) Net unrealized holding gain on cash flow hedges: Unrealized holding loss 3,126 — 3,126 Less: reclassification adjustment for gain realized in net loss 5,187 — 5,187 Net unrealized holding loss (2,061 ) — (2,061 ) Other comprehensive income (10,233 ) 2,956 (7,277 ) AOCI balance at September 30, 2015 $ 30,923 $ (5,739 ) $ 25,184 Nine Months Ended September 30, 2015 Before Tax Amount Tax (Expense) Benefit Net-of-Tax Amount AOCI balance at December 31, 2014 $ 33,984 $ (6,518 ) $ 27,466 Foreign currency translation adjustment 3 — 3 Unrealized gain on available-for-sale securities: Unrealized holding gain 865 (319 ) 546 Less: reclassification adjustment for gain realized in net loss 3,036 (1,098 ) 1,938 Net unrealized holding gain (2,171 ) 779 (1,392 ) Net unrealized holding gain on cash flow hedges: Unrealized holding gain 14,191 — 14,191 Less: reclassification adjustment for gain realized in net loss 15,084 — 15,084 Net unrealized holding gain (893 ) — (893 ) Other comprehensive income (3,061 ) 779 (2,282 ) AOCI balance at September 30, 2015 $ 30,923 $ (5,739 ) $ 25,184 Three Months Ended September 30, 2014 Before Tax Amount Tax (Expense) Benefit Net-of-Tax Amount AOCI balance at June 30, 2014 $ 15,491 $ (5,550 ) $ 9,941 Foreign currency translation adjustment (3 ) — (3 ) Unrealized gain on available-for-sale securities: Unrealized holding gain 4,138 (1,493 ) 2,645 Less: reclassification adjustment for gain realized in net income — — — Net unrealized holding gain 4,138 (1,493 ) 2,645 Net unrealized holding gain on cash flow hedges: Unrealized holding gain 9,768 (3,521 ) 6,247 Less: reclassification adjustment for loss realized in net income 562 (203 ) 359 Net unrealized holding gain 10,330 (3,724 ) 6,606 Other comprehensive income 14,465 (5,217 ) 9,248 AOCI balance at September 30, 2014 $ 29,956 $ (10,767 ) $ 19,189 Nine Months Ended September 30, 2014 Before Tax Amount Tax (Expense) Benefit Net-of-Tax Amount AOCI balance at December 31, 2013 $ 7,756 $ (2,738 ) $ 5,018 Foreign currency translation adjustment (36 ) — (36 ) Unrealized gain on available-for-sale securities: Unrealized holding gain 8,580 (3,106 ) 5,474 Less: reclassification adjustment for gain realized in net loss — — — Net unrealized holding gain 8,580 (3,106 ) 5,474 Net unrealized holding gain on cash flow hedges: Unrealized holding gain 14,691 (5,296 ) 9,395 Less: reclassification adjustment for loss realized in net loss (1,035 ) 373 (662 ) Net unrealized holding gain 13,656 (4,923 ) 8,733 Other comprehensive income 22,200 (8,029 ) 14,171 AOCI balance at September 30, 2014 $ 29,956 $ (10,767 ) $ 19,189

REVENUE AND CREDIT CONCENTRAT40

REVENUE AND CREDIT CONCENTRATIONS (Tables) - Net Product Revenue	9 Months Ended
	Sep. 30, 2015
Geographic Concentration Risk
Concentration Risk [Line Items]
Schedules of Consolidated Net Product Revenue Concentration	The table below summarizes consolidated net product revenue concentrations based on patient location for Vimizim, Naglazyme, Kuvan and Firdapse which are sold directly by the Company and global sales of Aldurazyme which is marketed by Genzyme Corporation (Genzyme). Genzyme is the Company’s sole customer for Aldurazyme and is responsible for marketing and selling Aldurazyme to third-parties. Net product revenues from Genzyme are comprised of royalties on worldwide net Aldurazyme sales and incremental product transfer revenues. Three Months Ended September 30, Nine Months Ended September 30, 2015 2014 2015 2014 Net product revenue marketed by the Company United States 44 % 42 % 38 % 37 % Europe 21 % 22 % 20 % 19 % Latin America 12 % 8 % 19 % 15 % Rest of world 13 % 15 % 14 % 16 % Total net product revenue marketed by the Company 90 % 87 % 91 % 87 % Aldurazyme net product revenues marketed by Genzyme 10 % 13 % 9 % 13 % Total net product revenue 100 % 100 % 100 % 100 %
Customer Concentration Risk
Concentration Risk [Line Items]
Schedules of Consolidated Net Product Revenue Concentration	The following table illustrates the percentage of the Company’s consolidated net product revenue attributed to the Company’s five largest customers. Three Months Ended September 30, Nine Months Ended September 30, 2015 2014 2015 2014 Customer A 15 % 17 % 14 % 15 % Customer B (1) 9 % 13 % 8 % 13 % Customer C 6 % 4 % 13 % 11 % Customer D 9 % 13 % 11 % 11 % Customer E 13 % — 5 % — Total 52 % 47 % 51 % 50 % (1) Genzyme is the Company’s sole customer for Aldurazyme and is responsible for marketing and selling Aldurazyme to third-parties. Net product revenues from Genzyme are comprised of royalties on worldwide net Aldurazyme sales and incremental product transfer revenue.

SEGMENT INFORMATION (Tables)

SEGMENT INFORMATION (Tables)	9 Months Ended
	Sep. 30, 2015
Segment Reporting [Abstract]
Segment Information by Product Revenue	The Company operates in one business segment, which primarily focuses on the development and commercialization of innovative biopharmaceuticals for serious diseases and medical conditions. All products are included in one segment because the majority of the Company’s products have similar economic and other characteristics, including the nature of the products and production processes, type of customers, distribution methods and regulatory environment. Three Months Ended September 30, Nine Months Ended September 30, 2015 2014 2015 2014 Net product revenue by product: Vimizim $ 65,106 $ 25,239 $ 169,608 $ 40,389 Naglazyme 54,131 67,511 243,386 245,954 Kuvan 64,219 53,438 174,501 145,578 Aldurazyme 20,509 22,553 58,991 64,727 Firdapse 3,802 4,675 11,616 14,016 Total net product revenue $ 207,767 $ 173,416 $ 658,102 $ 510,664
Summary of Total Revenues from External Customers and Collaborative Partners by Geographic Region	The following table summarizes total revenues from external customers and collaborative partners by geographic region. Three Months Ended September 30, Nine Months Ended September 30, 2015 2014 2015 2014 Total revenues by geographic region: United States $ 112,254 $ 98,070 $ 310,209 $ 259,738 Europe 42,822 39,743 127,796 102,808 Latin America 25,588 14,292 127,147 78,116 Rest of world 28,240 24,444 96,807 78,554 Total revenues $ 208,904 $ 176,549 $ 661,959 $ 519,216

Nature of Operations and Busi42

Nature of Operations and Business Risks - Additional Information (Detail)	9 Months Ended
	Sep. 30, 2015Product
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Number of approved products	5

Recent Accounting Pronounceme43

Recent Accounting Pronouncements - Additional Information (Detail) $ in Millions	Sep. 30, 2015USD ($)
Recent Accounting Pronouncements [Abstract]
Reclassification of deferred offering costs	$ 12.6

Acquisitions - Additional Infor

Acquisitions - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands	Jan. 29, 2015	Mar. 10, 2014	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2014
Business Acquisition [Line Items]
Business acquisitions, net of cash acquired					$ 538,392
Contingent consideration payable			$ 129,200		129,200
Net gain recognized due to early termination of lease and realization of remaining balance in deferred rent and reversal of asset retirement obligation						$ 8,893
Prosensa Holding N.V
Business Acquisition [Line Items]
Business acquisitions, net of cash acquired	$ 751,500
Business combination transaction costs	9,700				7,000		$ 2,700
Business acquisition, cash paid	680,100
Contractual right, amount	160,000
Acquired IPR&D	772,808
Prosensa Holding N.V | Kyndrisa and Prosensa's other primary product candidates
Business Acquisition [Line Items]
Acquired IPR&D	731,800
Prosensa Holding N.V | PRO 044
Business Acquisition [Line Items]
Acquired IPR&D	16,900
Prosensa Holding N.V | PRO-045
Business Acquisition [Line Items]
Acquired IPR&D	$ 24,100
Prosensa Holding N.V | CVRs
Business Acquisition [Line Items]
Contractual right, share price	$ 4.14
Contingent consideration payable	$ 71,400
Prosensa Holding N.V | Prosensa Shares
Business Acquisition [Line Items]
Business acquisition, cash paid	$ 620,700
Approximate percentage of shares tendered at closing of initial offering	96.80%
Prosensa Holding N.V | Remaining Prosensa share holders
Business Acquisition [Line Items]
Business acquisition, cash paid	$ 20,800
Prosensa Holding N.V | Vested options for Prosensa shares
Business Acquisition [Line Items]
Business acquisition, cash paid	$ 38,600
San Rafael Corporate Center
Business Acquisition [Line Items]
Business acquisition, cash paid		$ 116,500
Net gain recognized due to early termination of lease and realization of remaining balance in deferred rent and reversal of asset retirement obligation						8,800
San Rafael Corporate Center | Royalty, License and Other Revenues
Business Acquisition [Line Items]
Tenant revenue, other real estate			600	$ 1,300	2,100	3,100
Amortization expense			$ 300	$ 300	$ 1,000	1,000
San Rafael Corporate Center | Selling, General and Administrative
Business Acquisition [Line Items]
Business combination transaction costs						300
Net gain recognized due to early termination of lease and realization of remaining balance in deferred rent and reversal of asset retirement obligation						2,700
San Rafael Corporate Center | Research and Development
Business Acquisition [Line Items]
Net gain recognized due to early termination of lease and realization of remaining balance in deferred rent and reversal of asset retirement obligation						$ 6,100

Allocation of Purchase Consider

Allocation of Purchase Consideration Including Contingent Acquisition Consideration Payable (Detail) - USD ($) $ in Thousands	Sep. 30, 2015	Jan. 29, 2015	Dec. 31, 2014	[1]
Business Acquisition [Line Items]
Goodwill	$ 202,392		$ 54,258
Prosensa Holding N.V
Business Acquisition [Line Items]
Cash and cash equivalents		$ 141,669
Trade accounts receivable		3,086
Other current assets		1,537
Property, plant and equipment		2,683
Intangible assets		497
Other assets		104
Acquired IPR&D		772,808
Total identifiable assets acquired		922,384
Accounts payable and accrued expenses		(68,799)
Debt assumed		(57,053)
Deferred tax liability		(193,202)
Total liabilities assumed		(319,054)
Net identifiable assets acquired		603,330
Goodwill		148,134
Net assets acquired		$ 751,464
[1]	December 31, 2014 balances were derived from the audited Consolidated Financial Statements included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2014, filed with the Securities and Exchange Commission (the SEC) on March 2, 2015.

Summary of Estimated Fair Value

Summary of Estimated Fair Values of Assets Acquired and Liabilities Assumed (Detail) - San Rafael Corporate Center - USD ($) $ in Thousands	Mar. 10, 2014	Sep. 30, 2015
Business Acquisition [Line Items]
Building and improvements	$ 94,414
Land	14,565
Land improvements	3,616
Intangible assets	3,905
Net identifiable assets acquired	$ 116,500
Estimated useful lives		Remaining lease terms
Building and Improvements
Business Acquisition [Line Items]
Estimated useful lives	50 years
Land Improvements
Business Acquisition [Line Items]
Estimated useful lives	10 years

Fair Value of Identifiable Leas

Fair Value of Identifiable Lease Intangible assets Acquired by Asset Class (Detail) - San Rafael Corporate Center $ in Thousands	Mar. 10, 2014USD ($)
Business Acquisition [Line Items]
Fair value of identifiable lease intangible assets	$ 3,905
Above Market Leases
Business Acquisition [Line Items]
Fair value of identifiable lease intangible assets	351
In Place Leases
Business Acquisition [Line Items]
Fair value of identifiable lease intangible assets	$ 3,554

Stockholders' Equity - Addition

Stockholders' Equity - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended	9 Months Ended
	Jan. 31, 2015	Sep. 30, 2015	Sep. 30, 2014
Equity [Abstract]
Common stock, shares issued	9,775,000
Common stock, issue price	$ 93.25
Proceeds from public offering of common stock, net	$ 888,300	$ 888,257	$ 117,464

Computation of Basic and Dilute

Computation of Basic and Diluted Earnings per Common Share (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Earnings Per Share [Abstract]
Net income (loss), basic	$ (90,926)	$ 7,445	$ (240,416)	$ (64,172)
Interest expense related to the 2017 Notes		156
Gain on common stock held by the NQDC	(4,980)
Net income (loss), diluted	$ (95,906)	$ 7,601	$ (240,416)	$ (64,172)
Weighted average common shares outstanding, basic	160,886	147,016	159,647	145,724
Options to purchase common stock		9,275
Common stock issuable under the 2017 Notes		2,238
Unvested RSUs		642
Potentially issuable common stock of ESPP purchases		133
Common shares held by the NQDC	248
Weighted-average common shares outstanding, diluted	161,134	159,304	159,647	145,724
Net income (loss) per common share, basic	$ (0.57)	$ 0.05	$ (1.51)	$ (0.44)
Net income (loss) per common share, diluted	$ (0.60)	$ 0.05	$ (1.51)	$ (0.44)

Anti-Dilutive Common Stock Excl

Anti-Dilutive Common Stock Excluded From Computation of Diluted Net Income (Loss) Per Share (Detail) - shares shares in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Potential shares of common stock excluded from computation of earnings (loss) per share as they are anti-dilutive	22,008	12,240	22,123	24,559
Stock Option
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Potential shares of common stock excluded from computation of earnings (loss) per share as they are anti-dilutive	10,503	3,491	10,503	12,780
Common stock issuable under the 2017 Notes
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Potential shares of common stock excluded from computation of earnings (loss) per share as they are anti-dilutive	1,553		1,553	2,238
Common stock issuable under the 2018 and 2020 Notes
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Potential shares of common stock excluded from computation of earnings (loss) per share as they are anti-dilutive	7,966	7,966	7,966	7,966
Unvested restricted stock units
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Potential shares of common stock excluded from computation of earnings (loss) per share as they are anti-dilutive	1,757	559	1,633	1,216
Potentially issuable common stock for ESPP purchases
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Potential shares of common stock excluded from computation of earnings (loss) per share as they are anti-dilutive	229		220	135
Common stock held by the NQDC
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Potential shares of common stock excluded from computation of earnings (loss) per share as they are anti-dilutive		224	248	224

Net Income (Loss) Per Common 51

Net Income (Loss) Per Common Share - Additional Information (Detail)	Sep. 30, 2015$ / shares
The Notes
Earnings Per Share [Line Items]
Debt instrument, convertible, conversion price, per share	$ 94.15
Convertible Notes due 2018
Earnings Per Share [Line Items]
Debt instrument, interest rate, stated percentage, per annum	0.75%
Convertible Notes due 2020
Earnings Per Share [Line Items]
Debt instrument, interest rate, stated percentage, per annum	1.50%

Amortized Cost Gross Unrealized

Amortized Cost Gross Unrealized Holding Gain or Loss and Fair Value of Available for Sale Security by Major Security Type (Detail) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	$ 756,547	$ 167,830
Gross Unrealized Holding Gains	575	74
Gross Unrealized Holding Losses	(757)	(342)
Aggregate Fair Value	756,365	167,562
Certificates of Deposit
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	57,687	72,302
Gross Unrealized Holding Gains	1	1
Aggregate Fair Value	57,688	72,303
Corporate Debt Securities
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	413,955	95,478
Gross Unrealized Holding Gains	216
Gross Unrealized Holding Losses	(757)	(342)
Aggregate Fair Value	413,414	95,136
Commercial Paper
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	60,892
Aggregate Fair Value	60,892
US Government Agency Securities
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	223,963
Gross Unrealized Holding Gains	278
Aggregate Fair Value	224,241
Greek Government-Issued Bonds
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	50	50
Gross Unrealized Holding Gains	80	73
Aggregate Fair Value	$ 130	$ 123

Investments - Additional Inform

Investments - Additional Information (Detail) $ in Millions	9 Months Ended	12 Months Ended
	Sep. 30, 2015USD ($)Investment	Dec. 31, 2014USD ($)
Investments Debt And Equity Securities [Abstract]
Number of investments in marketable equity securities | Investment	2
Fair value of marketable equity securities	$ 21.4	$ 30.8
Marketable equity securities, unrealized gain (loss)	$ 16	$ 18.3

Fair Values of Available-For-Sa

Fair Values of Available-For-Sale Securities by Contractual Maturity (Detail) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Investments Debt And Equity Securities [Abstract]
Maturing in one year or less	$ 241,984	$ 69,706
Maturing after one year through five years	514,381	97,856
Total	$ 756,365	$ 167,562

Goodwill - Schedule of Change55

Goodwill - Schedule of Changes in Goodwill (Detail) $ in Thousands	9 Months Ended
	Sep. 30, 2015USD ($)
Goodwill And Intangible Assets Disclosure [Abstract]
Beginning Balance	$ 54,258	[1]
Addition of goodwill related to the acquisition of Prosensa	148,134
Ending Balance	$ 202,392
[1]	December 31, 2014 balances were derived from the audited Consolidated Financial Statements included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2014, filed with the Securities and Exchange Commission (the SEC) on March 2, 2015.

Intangible Assets (Detail)

Intangible Assets (Detail) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Intangible assets:
Finite-lived intangible assets	$ 123,732	$ 123,365
Indefinite-lived intangible assets	812,088	74,430
Indefinite-lived intangible assets held-for-sale	35,150
Gross intangible assets:	970,970	197,795
Less: Accumulated amortization	(50,027)	(41,217)
Net carrying value	$ 920,943	$ 156,578	[1]
[1]	December 31, 2014 balances were derived from the audited Consolidated Financial Statements included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2014, filed with the Securities and Exchange Commission (the SEC) on March 2, 2015.

Intangible Assets - Additional

Intangible Assets - Additional Information (Detail) $ in Thousands	Sep. 30, 2015USD ($)
Goodwill And Intangible Assets Disclosure [Abstract]
Carrying value of Intangible assets held for sale	$ 35,150

Property Plant and Equipment (D

Property Plant and Equipment (Detail) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 869,806	$ 752,405
Less: Accumulated depreciation	(265,293)	(228,889)
Total property, plant and equipment, net	604,513	523,516	[1]
Leasehold Improvements
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	41,364	39,297
Building and Improvements
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	354,957	335,991
Manufacturing and Laboratory Equipment
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	136,432	124,564
Computer Hardware and Software
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	106,453	97,032
Furniture and Equipment
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	16,465	13,717
Land Improvements
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	4,557	4,106
Land
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	29,358	29,358
Construction-in-Progress
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 180,220	$ 108,340
[1]	December 31, 2014 balances were derived from the audited Consolidated Financial Statements included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2014, filed with the Securities and Exchange Commission (the SEC) on March 2, 2015.

Property Plant and Equipment -

Property Plant and Equipment - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Property Plant And Equipment [Abstract]
Depreciation expense	$ 12,700	$ 11,200	$ 36,400	$ 31,300
Depreciation capitalized into inventory	$ 3,700	$ 2,600	$ 11,005	$ 7,989

Schedule of Inventory (Detail)

Schedule of Inventory (Detail) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Inventory Disclosure [Abstract]
Raw materials	$ 41,761	$ 22,488
Work-in-process	137,751	114,393
Finished goods	82,588	62,571
Total inventory	$ 262,100	$ 199,452	[1]
[1]	December 31, 2014 balances were derived from the audited Consolidated Financial Statements included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2014, filed with the Securities and Exchange Commission (the SEC) on March 2, 2015.

Schedule of Other Current Asset

Schedule of Other Current Assets (Detail) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Condensed Financial Information Of Subsidiaries Disclosure [Abstract]
Prepaid expenses	$ 73,171	$ 35,390
Short-term forward currency exchange contract assets	16,396	10,513
Promissory notes receivable, net		46,946
Restricted investments	7,346	2,354
Convertible promissory note conversion option		2,386
Other receivables	12,606	9,733
Other	5,811	4,513
Total other current assets	$ 115,330	$ 111,835	[1]
[1]	December 31, 2014 balances were derived from the audited Consolidated Financial Statements included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2014, filed with the Securities and Exchange Commission (the SEC) on March 2, 2015.

Schedule of Other Assets (Detai

Schedule of Other Assets (Detail) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Condensed Financial Information Of Subsidiaries Disclosure [Abstract]
Deposits	$ 19,957	$ 12,021
Deferred debt offering costs	9,259	11,763
Strategic investments	21,420	30,811
Long-term forward foreign currency exchange contract assets	3,642	5,387
Other	6,512	6,338
Total other assets	$ 60,790	$ 66,320	[1]
[1]	December 31, 2014 balances were derived from the audited Consolidated Financial Statements included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2014, filed with the Securities and Exchange Commission (the SEC) on March 2, 2015.

Schedule of Accounts Payable an

Schedule of Accounts Payable and Accrued Liabilities (Detail) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Condensed Financial Information Of Parent Company Only Disclosure [Abstract]
Accounts payable and accrued operating expenses	$ 162,926	$ 139,513
Accrued compensation expense	62,674	45,479
Accrued vacation expense	15,450	12,540
Accrued rebates payable	27,357	14,859
Accrued royalties payable	9,886	9,050
Value added taxes payable	6,040	5,479
Other	11,867	4,924
Total accounts payable and accrued liabilities	$ 296,200	$ 231,844	[1]
[1]	December 31, 2014 balances were derived from the audited Consolidated Financial Statements included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2014, filed with the Securities and Exchange Commission (the SEC) on March 2, 2015.

Summary of Convertible Debt (De

Summary of Convertible Debt (Detail) - USD ($) $ in Thousands		Sep. 30, 2015	Dec. 31, 2014
Debt Instrument [Line Items]
Long-term Convertible Notes, net of unamortized discount		$ 667,793	$ 657,976	[1]
Convertible Notes, fair value		1,156,370	1,079,792
Convertible Notes due 2020
Debt Instrument [Line Items]
Long-term Convertible Notes, net of unamortized discount		306,561	297,955
Convertible Notes, fair value	[2]	503,706	456,360
Convertible Notes due 2018
Debt Instrument [Line Items]
Long-term Convertible Notes, net of unamortized discount		329,604	319,463
Convertible Notes, fair value	[2]	488,858	442,448
Convertible Notes due 2017
Debt Instrument [Line Items]
Long-term Convertible Notes, net of unamortized discount		31,628	40,558
Convertible Notes, fair value	[2]	$ 163,806	$ 180,984
[1]	December 31, 2014 balances were derived from the audited Consolidated Financial Statements included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2014, filed with the Securities and Exchange Commission (the SEC) on March 2, 2015.
[2]	The fair value of the Company’s fixed rate convertible debt is based on open market trades and is classified as Level 1 in the fair value hierarchy.

Summary of Convertible Debt (Pa

Summary of Convertible Debt (Parenthetical) (Detail) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Convertible Notes due 2020
Debt Instrument [Line Items]
Long-term convertible debt, unamortized discount	$ 68,432	$ 77,045
Convertible Notes due 2018
Debt Instrument [Line Items]
Long-term convertible debt, unamortized discount	$ 45,376	$ 55,537

Summary of Interest Expense on

Summary of Interest Expense on Convertible Debt (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Schedule Of Interest Expenses [Line Items]
Total interest expense on convertible debt	$ 9,447	$ 9,118	$ 28,911	$ 27,445
Convertible Senior Notes
Schedule Of Interest Expenses [Line Items]
Coupon interest	2,283	2,278	7,667	7,140
Amortization of issuance costs	823	828	2,471	2,505
Accretion of debt discount	6,341	6,012	18,773	17,800
Total interest expense on convertible debt	$ 9,447	$ 9,118	$ 28,911	$ 27,445

Convertible Debt - Additional I

Convertible Debt - Additional Information (Detail) $ in Thousands	9 Months Ended
	Sep. 30, 2015USD ($)Agreementshares	Sep. 30, 2014USD ($)Agreementshares
Debt Conversion [Line Items]
Convertible cash premium paid to holder for agreeing to convert	$ 163	$ 674
Convertible Notes due 2017
Debt Conversion [Line Items]
Number of agreements | Agreement	3	2
Convertible notes aggregate principal	$ 8,100	$ 16,500
Notes converted, number of shares | shares	399,469	809,351
Convertible cash premium paid to holder for agreeing to convert	$ 200	$ 700
Convertible Notes due 2017 | Convertible Senior Notes
Debt Conversion [Line Items]
Convertible cash premium paid to holder for agreeing to convert	$ 200	$ 700

Derivative Instruments and He68

Derivative Instruments and Hedging Strategies - Additional Information (Detail) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2015USD ($)	Sep. 30, 2014USD ($)	Sep. 30, 2015USD ($)	Sep. 30, 2014USD ($)	Dec. 31, 2014USD ($)	Sep. 30, 2015EUR (€)Derivative	Sep. 30, 2015BRLDerivative	Sep. 30, 2015GBP (£)Derivative
Derivative [Line Items]
Amount reclassified from accumulated other comprehensive income to earnings as related to forecasted revenue transactions | $	$ 5,187	$ 359	$ 15,084	$ (662)
Gain (Loss) from foreign currency exchange contracts in accumulated other comprehensive income | $			$ 15,000		$ 15,900
Minimum
Derivative [Line Items]
Maturity period of foreign currency derivatives			Oct. 31, 2015
Maximum
Derivative [Line Items]
Maturity period of foreign currency derivatives			Sep. 30, 2018
Foreign Currency Derivatives
Derivative [Line Items]
Amount reclassified from accumulated other comprehensive income to earnings as related to forecasted revenue transactions | $			$ 15,100
Maximum length of time over which hedging its exposure to the reduction in value of forecasted foreign currency cash flows through foreign currency forward contracts			12 months
Foreign Currency Derivatives | Maximum
Derivative [Line Items]
Maturity period of foreign currency derivatives			Sep. 30, 2018
Derivatives Designated As Hedging Instruments | Euro
Derivative [Line Items]
Number of forward foreign currency exchange contracts outstanding						215	215	215
Derivatives Designated As Hedging Instruments | Sale Contracts
Derivative [Line Items]
Number of forward foreign currency exchange contracts outstanding						1	1	1
Derivatives Designated As Hedging Instruments | Purchase | Euro
Derivative [Line Items]
Number of forward foreign currency exchange contracts outstanding						160	160	160
Derivatives Designated As Hedging Instruments | Foreign Currency Derivatives | Sale Contracts
Derivative [Line Items]
Outstanding forward foreign currency exchange contracts						€ 296,400,000	BRL 70,000,000
Derivatives Designated As Hedging Instruments | Foreign Currency Derivatives | Purchase | Sale Contracts
Derivative [Line Items]
Outstanding forward foreign currency exchange contracts | €						€ 155,100,000
Not Designated as Hedging Instrument
Derivative [Line Items]
Maturity period of foreign currency derivatives			Oct. 30, 2015
Not Designated as Hedging Instrument | Sale Contracts
Derivative [Line Items]
Number of forward foreign currency exchange contracts outstanding						1	1	1
Not Designated as Hedging Instrument | Purchase Contracts
Derivative [Line Items]
Number of forward foreign currency exchange contracts outstanding						1	1	1
Not Designated as Hedging Instrument | Foreign Currency Derivatives | Sale Contracts
Derivative [Line Items]
Outstanding forward foreign currency exchange contracts						€ 58,000,000		£ 7,100,000
Not Designated as Hedging Instrument | Foreign Currency Derivatives | Purchase Contracts
Derivative [Line Items]
Outstanding forward foreign currency exchange contracts | €						€ 7,000,000

Derivative Instruments and He69

Derivative Instruments and Hedging Strategies (Detail) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Derivative [Line Items]
Derivative Asset, Fair Value	$ 20,038	$ 15,900
Derivative Liability, Fair Value	5,819	12
Derivatives Designated As Hedging Instruments
Derivative [Line Items]
Derivative Asset, Fair Value	19,968	15,593
Derivative Liability, Fair Value	5,688
Derivatives Designated As Hedging Instruments | Forward Foreign Currency Exchange Contracts | Other Current Assets
Derivative [Line Items]
Derivative Asset, Fair Value	16,326	10,206
Derivatives Designated As Hedging Instruments | Forward Foreign Currency Exchange Contracts | Other Assets
Derivative [Line Items]
Derivative Asset, Fair Value	3,642	5,387
Derivatives Designated As Hedging Instruments | Forward Foreign Currency Exchange Contracts | Accounts Payable and Accrued Liabilities
Derivative [Line Items]
Derivative Liability, Fair Value	2,502
Derivatives Designated As Hedging Instruments | Forward Foreign Currency Exchange Contracts | Other Long-Term Liabilities
Derivative [Line Items]
Derivative Liability, Fair Value	3,186
Not Designated as Hedging Instrument
Derivative [Line Items]
Derivative Asset, Fair Value	70	307
Derivative Liability, Fair Value	131	12
Not Designated as Hedging Instrument | Forward Foreign Currency Exchange Contracts | Other Current Assets
Derivative [Line Items]
Derivative Asset, Fair Value	70	307
Not Designated as Hedging Instrument | Forward Foreign Currency Exchange Contracts | Accounts Payable and Accrued Liabilities
Derivative [Line Items]
Derivative Liability, Fair Value	$ 131	$ 12

Effect of Derivative Instrument

Effect of Derivative Instruments (Detail) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended		12 Months Ended
		Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2014
Derivative Instruments, Gain (Loss) [Line Items]
Net gain recognized in Other Comprehensive Income (OCI)				$ 15,000		$ 15,900
Forward Foreign Currency Exchange Contracts | Derivatives Designated As Hedging Instruments
Derivative Instruments, Gain (Loss) [Line Items]
Net gain recognized in Other Comprehensive Income (OCI)	[1]	$ 3,126	$ 6,247	14,191	$ 9,395
Net gain (loss) reclassified from accumulated OCI into earnings	[2]	5,187	359	15,084	(662)
Net gain (loss) recognized in net income (loss)	[3]	(264)	(179)	(404)	(499)
Forward Foreign Currency Exchange Contracts | Not Designated as Hedging Instrument
Derivative Instruments, Gain (Loss) [Line Items]
Net gain (loss) recognized in net income (loss)	[4]	$ (514)	$ 4,365	$ 6,052	$ 4,861
[1]	Net change in the fair value of the effective portion classified as OCI.
[2]	Effective portion classified as net product revenue or SG&A expense.
[3]	Ineffective portion and amount excluded from effectiveness testing classified as SG&A expense.
[4]	Classified as SG&A expense.

Fair Value of Financial Assets

Fair Value of Financial Assets and Liabilities (Detail) - USD ($) $ in Thousands		Sep. 30, 2015	Dec. 31, 2014
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of Available-for-sale securities		$ 756,365	$ 167,562
Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of Cash and cash equivalents		376,346	875,486
Fair value of Available-for-sale securities		756,365	167,562
Fair value of other current assets		24,090	15,767
Fair value of other non-current assets		31,051	41,310
Fair value of financial assets, Total		1,187,852	1,100,125
Fair value of other current liabilities		99,055	6,211
Fair value of other non-current liabilities		68,390	62,332
Fair value of financial liabilities, Total		167,445	68,543
Fair Value, Measurements, Recurring | Overnight Deposits
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of Cash and cash equivalents		277,738	225,159
Fair Value, Measurements, Recurring | Money Market Instruments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of Cash and cash equivalents		98,608	650,327
Fair Value, Measurements, Recurring | Nonqualified Deferred Compensation Plan Liability
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of other current liabilities		2,131	2,304
Fair value of other non-current liabilities		30,330	23,565
Fair Value, Measurements, Recurring | Forward Foreign Currency Exchange Contract, Liability
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of other current liabilities	[1]	2,633	12
Fair value of other non-current liabilities	[1]	3,186
Fair Value, Measurements, Recurring | Contingent Acquisition Consideration Payable
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of other current liabilities		94,291	3,895
Fair value of other non-current liabilities		34,874	38,767
Fair Value, Measurements, Recurring | Certificates of Deposit
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of Available-for-sale securities, current		50,138	54,174
Fair value of Available-for-sale securities, non-current		7,550	18,129
Fair Value, Measurements, Recurring | Corporate Debt Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of Available-for-sale securities, current		57,446	15,532
Fair value of Available-for-sale securities, non-current		355,968	79,604
Fair Value, Measurements, Recurring | Commercial Paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of Available-for-sale securities, current		60,892
Fair Value, Measurements, Recurring | US Government Agency Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of Available-for-sale securities, current		73,508
Fair value of Available-for-sale securities, non-current		150,733
Fair Value, Measurements, Recurring | Greek Government-Issued Bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of Available-for-sale securities, non-current		130	123
Fair Value, Measurements, Recurring | Nonqualified Deferred Compensation Plan Assets
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of other current assets		348	514
Fair value of other non-current assets		5,989	5,112
Fair Value, Measurements, Recurring | Forward Foreign Current Exchange Contract Assets
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of other current assets	[1]	16,396	10,513
Fair value of other non-current assets	[1]	3,642
Fair Value, Measurements, Recurring | Restrictive Investments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of other current assets	[2]	7,346	2,354
Fair value of other non-current assets	[2]		5,387
Fair Value, Measurements, Recurring | Strategic Investment
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of other non-current assets	[3]	21,420	30,811
Fair Value, Measurements, Recurring | Embedded Derivative
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of other current assets	[4]		2,386
Fair Value, Measurements, Recurring | Quoted Price In Active Markets For Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of Cash and cash equivalents		277,738	225,159
Fair value of other non-current assets		21,420	30,811
Fair value of financial assets, Total		299,158	255,970
Fair value of other current liabilities		1,783	1,790
Fair value of other non-current liabilities		24,341	18,453
Fair value of financial liabilities, Total		26,124	20,243
Fair Value, Measurements, Recurring | Quoted Price In Active Markets For Identical Assets (Level 1) | Overnight Deposits
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of Cash and cash equivalents		277,738	225,159
Fair Value, Measurements, Recurring | Quoted Price In Active Markets For Identical Assets (Level 1) | Nonqualified Deferred Compensation Plan Liability
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of other current liabilities		1,783	1,790
Fair value of other non-current liabilities		24,341	18,453
Fair Value, Measurements, Recurring | Quoted Price In Active Markets For Identical Assets (Level 1) | Strategic Investment
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of other non-current assets	[3]	21,420	30,811
Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of Cash and cash equivalents		98,608	650,327
Fair value of Available-for-sale securities		756,365	167,562
Fair value of other current assets		24,090	13,381
Fair value of other non-current assets		9,631	10,499
Fair value of financial assets, Total		888,694	841,769
Fair value of other current liabilities		2,981	526
Fair value of other non-current liabilities		9,175	5,112
Fair value of financial liabilities, Total		12,156	5,638
Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2) | Money Market Instruments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of Cash and cash equivalents		98,608	650,327
Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2) | Nonqualified Deferred Compensation Plan Liability
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of other current liabilities		348	514
Fair value of other non-current liabilities		5,989	5,112
Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2) | Forward Foreign Currency Exchange Contract, Liability
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of other current liabilities	[1]	2,633	12
Fair value of other non-current liabilities	[1]	3,186
Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2) | Certificates of Deposit
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of Available-for-sale securities, current		50,138	54,174
Fair value of Available-for-sale securities, non-current		7,550	18,129
Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2) | Corporate Debt Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of Available-for-sale securities, current		57,446	15,532
Fair value of Available-for-sale securities, non-current		355,968	79,604
Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2) | Commercial Paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of Available-for-sale securities, current		60,892
Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2) | US Government Agency Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of Available-for-sale securities, current		73,508
Fair value of Available-for-sale securities, non-current		150,733
Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2) | Greek Government-Issued Bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of Available-for-sale securities, non-current		130	123
Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2) | Nonqualified Deferred Compensation Plan Assets
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of other current assets		348	514
Fair value of other non-current assets		5,989	5,112
Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2) | Forward Foreign Current Exchange Contract Assets
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of other current assets	[1]	16,396	10,513
Fair value of other non-current assets	[1]	3,642
Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2) | Restrictive Investments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of other current assets	[2]	7,346	2,354
Fair value of other non-current assets	[2]		5,387
Fair Value, Measurements, Recurring | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of other current assets			2,386
Fair value of financial assets, Total			2,386
Fair value of other current liabilities		94,291	3,895
Fair value of other non-current liabilities		34,874	38,767
Fair value of financial liabilities, Total		129,165	42,662
Fair Value, Measurements, Recurring | Significant Unobservable Inputs (Level 3) | Contingent Acquisition Consideration Payable
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of other current liabilities		94,291	3,895
Fair value of other non-current liabilities		$ 34,874	38,767
Fair Value, Measurements, Recurring | Significant Unobservable Inputs (Level 3) | Embedded Derivative
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of other current assets	[4]		$ 2,386
[1]	See Note 14 to these Condensed Consolidated Financial Statements for further information regarding the derivative instruments.
[2]	The restricted investments at September 30, 2015 and December 31, 2014 secure the Company’s irrevocable standby letter of credit obtained in connection with certain commercial agreements.
[3]	The Company has investments in marketable equity securities measured using quoted prices in an active market that are considered strategic investments. See Note 8 to these Condensed Consolidated Financial Statements for additional discussion regarding the Company’s strategic investments.
[4]	The embedded derivative at December 31, 2014 represents the fair value of the conversion feature of a promissory note that may be settled in the issuer’s underlying shares.

Liabilities Measured at Fair Va

Liabilities Measured at Fair Value Using Level 3 Inputs (Detail) - Contingent Payment $ in Thousands	9 Months Ended
	Sep. 30, 2015USD ($)
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Contingent acquisition consideration payable, Beginning balance	$ 42,662
Addition of contingent consideration payable related to the Prosensa acquisition (CVR)	71,402
Changes in the fair value of contingent acquisition consideration payable	15,101
Contingent acquisition consideration payable, Ending balance	$ 129,165

Asset Retirement Obligation Lia

Asset Retirement Obligation Liability and Corresponding Capital Asset (Detail) $ in Thousands	9 Months Ended
	Sep. 30, 2015USD ($)
Asset Retirement Obligation Disclosure [Abstract]
Asset retirement obligation, Beginning balance	$ 3,765
Accretion expense	109
Additions	748
Payments	(29)
Asset retirement obligations, Ending balance	$ 4,593

Assumptions Used to Estimate Pe

Assumptions Used to Estimate Per Share Fair Value of Stock Options Granted (Detail) - Stock Option	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Dividend yield	0.00%	0.00%	0.00%	0.00%
Expected life		6 years 10 months 24 days		6 years 10 months 24 days
Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected volatility	41.00%	44.00%	39.00%	44.00%
Expected life	6 years 10 months 24 days		6 years 4 months 24 days
Risk-free interest rate	1.90%	2.00%	1.50%	2.00%
Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected volatility	44.00%	45.00%	45.00%	45.00%
Expected life	8 years		8 years
Risk-free interest rate	2.10%	2.20%	2.20%	2.30%

Stock Based Compensation - Addi

Stock Based Compensation - Additional Information (Detail) $ / shares in Units, $ in Thousands	Mar. 03, 2015shares	Sep. 30, 2015USD ($)shares	Sep. 30, 2014USD ($)	Sep. 30, 2015USD ($)$ / sharesshares	Sep. 30, 2014USD ($)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares, granted				718,670
Weighted-average fair value per option granted | $ / shares				$ 56.86
New stock purchase rights under the ESPP		0
Recognized compensation costs | $		$ 28,758	$ 20,004	$ 80,959	$ 53,559
Stock-based compensation capitalized to inventory | $				$ 8,300	5,700
Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares, granted				1,098,715
Weighted-average fair value per RSU granted | $ / shares				$ 120.55
Restricted Stock With Performance and Market Based Vesting Conditions
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted-average fair value per RSU granted | $ / shares				$ 34.66
Number of restricted stock units grants		860,000		860,000
Recognized compensation costs | $		$ 1,500	$ 700	$ 4,600	$ 1,600
Restricted Stock With Performance and Market Based Vesting Conditions | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total shareholder return, percentage of multiplier range				75.00%
Restricted Stock With Performance and Market Based Vesting Conditions | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total shareholder return, percentage of multiplier range				125.00%
Restricted Stock Unit Awards with Performance Conditions
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted-average fair value per RSU granted | $ / shares				$ 108.36
Number of restricted stock units grants	58,300
Recognized compensation costs | $		$ 500		$ 1,300
Award vesting service period	3 years
Number of units that could vest if performance condition is achieved and a revenue multiplier is applied	69,960
Restricted Stock Unit Awards with Performance Conditions | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Revenue multiplier	0.80
Restricted Stock Unit Awards with Performance Conditions | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Revenue multiplier	1.20

Compensation Expense (Detail)

Compensation Expense (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	$ 28,758	$ 20,004	$ 80,959	$ 53,559
Cost of Sales
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	1,386	1,180	4,484	3,807
Research and Development
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	12,578	8,279	34,972	22,300
Selling, General and Administrative
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	$ 14,794	$ 10,545	$ 41,503	$ 27,452

Amounts Reclassified out of Acc

Amounts Reclassified out of Accumulated Other Comprehensive Income (Loss) (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Net product revenues	$ 207,767	$ 173,416	$ 658,102	$ 510,664
Selling, general and administrative	(94,044)	(74,604)	(288,364)	(202,388)
Other income (expense)	(281)	(74)	(9,105)	(68)
Provision for (benefit from) income taxes	483	(4,224)	(7,273)	5,041
NET INCOME (LOSS)	(90,926)	7,445	(240,416)	(64,172)
Amount Reclassified from AOCI Gain (Loss) | Gain on sale of available-for-sale investment
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Other income (expense)	14		3,036
Amount Reclassified from AOCI Gain (Loss) | Gain (loss) on cash flow hedges: | Forward Foreign Currency Exchange Contracts
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Net product revenues	4,411	562	13,660	(1,035)
Selling, general and administrative	776		1,424
Provision for (benefit from) income taxes	5	203	1,098	(373)
NET INCOME (LOSS)	$ 5,196	$ 359	$ 17,022	$ (662)

Summary of Changes in Accumulat

Summary of Changes in Accumulated Balances of Other Comprehensive Income Loss Including Current Period Other Comprehensive Income and Reclassifications (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015		Sep. 30, 2014
Equity [Abstract]
Beginning Balance, before tax amount	$ 41,156	$ 15,491	$ 33,984		$ 7,756
Foreign currency translation adjustment, before tax amount		(3)	3		(36)
Unrealized gain on available-for-sale securities, before tax amount
Unrealized holding gain (loss), before tax amount	(8,158)	4,138	865		8,580
Less: reclassification adjustment for gain realized in net income (loss), before tax amount	14		3,036
Net unrealized holding gain (loss), before tax amount	(8,172)	4,138	(2,171)		8,580
Net unrealized holding gain (loss) on cash flow hedges, before tax amount
Unrealized holding gain (loss), before tax amount	3,126	9,768	14,191		14,691
Less: reclassification adjustment for gain (loss) realized in net income (loss), before tax amount	5,187	562	15,084		(1,035)
Net unrealized holding gain (loss), before tax amount	(2,061)	10,330	(893)		13,656
Other comprehensive income, before tax amount	(10,233)	14,465	(3,061)		22,200
Ending Balance, before tax amount	30,923	29,956	30,923		29,956
Beginning Balance, tax (expense) benefit	(8,695)	(5,550)	(6,518)		(2,738)
Unrealized gain on available-for-sale securities, tax (expense) benefit
Unrealized holding gain, tax (expense) benefit	2,951	(1,493)	(319)		(3,106)
Less: reclassification adjustment for gain realized in net income (loss), tax (expense) benefit	(5)		(1,098)
Net unrealized holding gain, tax (expense) benefit	2,956	(1,493)	779		(3,106)
Net unrealized holding gain (loss) on cash flow hedges, tax (expense) benefit
Unrealized holding gain (loss), tax (expense) benefit		(3,521)			(5,296)
Less: reclassification adjustment for gain (loss) realized in net income (loss), tax (expense) benefit		(203)			373
Net unrealized holding gain (loss), tax (expense) benefit		(3,724)			(4,923)
Other comprehensive income, tax (expense) benefit	2,956	(5,217)	779		(8,029)
Ending Balance, tax (expense) benefit	(5,739)	(10,767)	(5,739)		(10,767)
Beginning Balance, net of tax amount	32,461	9,941	27,466	[1]	5,018
Foreign currency translation adjustment, net of tax amount		(3)	3		(36)
Unrealized gain on available-for-sale securities, net of tax amount
Unrealized holding gain, net of tax amount	(5,207)	2,645	546		5,474
Less: reclassification adjustment for gain realized in net income (loss), net of tax amount	9		1,938
Net unrealized holding gain, net of tax amount	(5,216)	2,645	(1,392)		5,474
Net unrealized holding gain (loss) on cash flow hedges, net of tax amount
Unrealized holding gain (loss), net of tax amount	3,126	6,247	14,191		9,395
Less: reclassification adjustment for gain (loss) realized in net income (loss), net of tax amount	5,187	359	15,084		(662)
Net unrealized holding gain (loss), net of tax amount	(2,061)	6,606	(893)		8,733
Other comprehensive income, net of tax amount	(7,277)	9,248	(2,282)		14,171
Ending Balance, net of tax amount	$ 25,184	$ 19,189	$ 25,184		$ 19,189
[1]	December 31, 2014 balances were derived from the audited Consolidated Financial Statements included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2014, filed with the Securities and Exchange Commission (the SEC) on March 2, 2015.

Consolidated Net Product Revenu

Consolidated Net Product Revenue Concentrations Based on Patient Location (Detail) - Net Product Revenue	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Geographic Concentration Risk
Concentration Risk [Line Items]
Concentration risk, percentage	90.00%	87.00%	91.00%	87.00%
Geographic Concentration Risk | United States
Concentration Risk [Line Items]
Concentration risk, percentage	44.00%	42.00%	38.00%	37.00%
Geographic Concentration Risk | Europe
Concentration Risk [Line Items]
Concentration risk, percentage	21.00%	22.00%	20.00%	19.00%
Geographic Concentration Risk | Latin America
Concentration Risk [Line Items]
Concentration risk, percentage	12.00%	8.00%	19.00%	15.00%
Geographic Concentration Risk | Rest of World
Concentration Risk [Line Items]
Concentration risk, percentage	13.00%	15.00%	14.00%	16.00%
Customer Concentration Risk
Concentration Risk [Line Items]
Concentration risk, percentage	52.00%	47.00%	51.00%	50.00%
Customer Concentration Risk | Genzyme | Product Four
Concentration Risk [Line Items]
Concentration risk, percentage	10.00%	13.00%	9.00%	13.00%
Credit Concentration Risk
Concentration Risk [Line Items]
Concentration risk, percentage	100.00%	100.00%	100.00%	100.00%

Consolidated Net Product Reve80

Consolidated Net Product Revenue Concentrations Attributed to Largest Customers (Detail) - Customer Concentration Risk - Net Product Revenue		3 Months Ended		9 Months Ended
		Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Concentration Risk [Line Items]
Concentration risk, percentage		52.00%	47.00%	51.00%	50.00%
Customer A
Concentration Risk [Line Items]
Concentration risk, percentage		15.00%	17.00%	14.00%	15.00%
Customer B
Concentration Risk [Line Items]
Concentration risk, percentage	[1]	9.00%	13.00%	8.00%	13.00%
Customer C
Concentration Risk [Line Items]
Concentration risk, percentage		6.00%	4.00%	13.00%	11.00%
Customer D
Concentration Risk [Line Items]
Concentration risk, percentage		9.00%	13.00%	11.00%	11.00%
Customer E
Concentration Risk [Line Items]
Concentration risk, percentage		13.00%		5.00%
[1]	Genzyme is the Company’s sole customer for Aldurazyme and is responsible for marketing and selling Aldurazyme to third-parties. Net product revenues from Genzyme are comprised of royalties on worldwide net Aldurazyme sales and incremental product transfer revenue.

Revenue and Credit Concentrat81

Revenue and Credit Concentrations - Additional Information (Detail) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2015USD ($)	Sep. 30, 2014	Sep. 30, 2015USD ($)Customer	Sep. 30, 2014	Dec. 31, 2014USD ($)Customer
Concentration Risk [Line Items]
Accounts receivable, net	$ 148,949		$ 148,949		$ 144,472	[1]
Southern European Countries
Concentration Risk [Line Items]
Total amount past due	12,500		12,500
Total amount current due	8,100		8,100
Southern European Countries | Less than 30 days
Concentration Risk [Line Items]
Total amount past due	2,100		$ 2,100
Largest Customers
Concentration Risk [Line Items]
Number of customers accounted for largest balance in accounts receivable | Customer			2		2
Accounts receivable, net	$ 23,900		$ 23,900		$ 34,500
Credit Concentration Risk | Accounts Receivable | Larger Customer One
Concentration Risk [Line Items]
Concentration risk, percentage			31.00%		42.00%
Credit Concentration Risk | Accounts Receivable | Larger Customer Two
Concentration Risk [Line Items]
Concentration risk, percentage			17.00%		18.00%
Credit Concentration Risk | Net Product Revenue
Concentration Risk [Line Items]
Concentration risk, percentage	100.00%	100.00%	100.00%	100.00%
Geographic Concentration Risk | Accounts Receivable | Southern European Countries
Concentration Risk [Line Items]
Concentration risk, percentage			8.00%
Geographic Concentration Risk | Net Product Revenue
Concentration Risk [Line Items]
Concentration risk, percentage	90.00%	87.00%	91.00%	87.00%
Geographic Concentration Risk | Net Product Revenue | Southern European Countries
Concentration Risk [Line Items]
Concentration risk, percentage	4.00%		4.00%
[1]	December 31, 2014 balances were derived from the audited Consolidated Financial Statements included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2014, filed with the Securities and Exchange Commission (the SEC) on March 2, 2015.

Segment Information - Additiona

Segment Information - Additional Information (Detail)	9 Months Ended
	Sep. 30, 2015Segment
Segment Reporting [Abstract]
Number of operating business segment	1

Segment Information by Product

Segment Information by Product Revenue (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Revenue from External Customer [Line Items]
Net product revenues	$ 207,767	$ 173,416	$ 658,102	$ 510,664
Vimizim
Revenue from External Customer [Line Items]
Net product revenues	65,106	25,239	169,608	40,389
Naglazyme
Revenue from External Customer [Line Items]
Net product revenues	54,131	67,511	243,386	245,954
Kuvan
Revenue from External Customer [Line Items]
Net product revenues	64,219	53,438	174,501	145,578
Aldurazyme
Revenue from External Customer [Line Items]
Net product revenues	20,509	22,553	58,991	64,727
Firdapse
Revenue from External Customer [Line Items]
Net product revenues	$ 3,802	$ 4,675	$ 11,616	$ 14,016

Summary of Total Revenues from

Summary of Total Revenues from External Customers and Collaborative Partners by Geographic Region (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Revenue from External Customer [Line Items]
Total revenues	$ 208,904	$ 176,549	$ 661,959	$ 519,216
United States
Revenue from External Customer [Line Items]
Total revenues	112,254	98,070	310,209	259,738
Europe
Revenue from External Customer [Line Items]
Total revenues	42,822	39,743	127,796	102,808
Latin America
Revenue from External Customer [Line Items]
Total revenues	25,588	14,292	127,147	78,116
Rest of World
Revenue from External Customer [Line Items]
Total revenues	$ 28,240	$ 24,444	$ 96,807	$ 78,554

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Detail) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2015	Dec. 31, 2014	[1]
Commitments And Contingencies [Line Items]
Contingent payments upon achievement of certain regulatory and licensing milestones	$ 763,000
Contingent consideration payable	129,200
Short-term contingent acquisition consideration payable	94,291	$ 3,895
Purchase commitment for the next five years	58,900
Prosensa Holding N.V
Commitments And Contingencies [Line Items]
Contingent payments upon achievement of certain regulatory and licensing milestones	160,000
Completed Programs
Commitments And Contingencies [Line Items]
Contingent payments upon achievement of certain regulatory and licensing milestones	$ 22,900
[1]	December 31, 2014 balances were derived from the audited Consolidated Financial Statements included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2014, filed with the Securities and Exchange Commission (the SEC) on March 2, 2015.

Subsequent Events - Additional

Subsequent Events - Additional Information (Detail) - Subsequent Event € in Millions, $ in Millions	Oct. 06, 2015USD ($)	Oct. 02, 2015EUR (€)	Oct. 01, 2015EUR (€)
Medivation
Subsequent Event [Line Items]
Upfront payment received	$ 410
Milestone payments	$ 160
Merck Serono
Subsequent Event [Line Items]
Upfront Payment | €		€ 340
Maximum potential additional consideration milestone payments | €			€ 185