Jazz Pharmaceuticals (JAZZ) 10-Q 8 May 18 2018 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2018	Apr. 30, 2018
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Mar. 31, 2018
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	Q1
Trading Symbol	JAZZ
Entity Registrant Name	Jazz Pharmaceuticals plc
Entity Central Index Key	1,232,524
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		59,996,224

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents	$ 453,169	$ 386,035
Investments	255,000	215,000
Accounts receivable, net of allowances	281,424	224,129
Inventories	46,384	43,245
Prepaid expenses	27,476	23,182
Other current assets	62,868	76,686
Total current assets	1,126,321	968,277
Property, plant and equipment, net	178,920	170,080
Intangible assets, net	2,953,146	2,979,127
Goodwill	960,509	947,537
Deferred tax assets, net	38,103	34,559
Deferred financing costs	7,144	7,673
Other non-current assets	22,985	16,419
Total assets	5,287,128	5,123,672
Current liabilities:
Accounts payable	46,933	24,368
Accrued liabilities	240,544	198,779
Current portion of long-term debt	45,117	40,605
Income taxes payable	36,048	21,577
Deferred revenue	6,977	8,618
Total current liabilities	375,619	293,947
Deferred revenue, non-current	13,641	16,115
Long-term debt, less current portion	1,537,044	1,540,433
Deferred tax liabilities, net	382,072	383,472
Other non-current liabilities	192,181	176,608
Commitments and contingencies
Shareholders’ equity:
Ordinary shares	6	6
Non-voting euro deferred shares	55	55
Capital redemption reserve	472	472
Additional paid-in capital	1,955,756	1,935,486
Accumulated other comprehensive loss	(98,768)	(140,878)
Retained earnings	929,050	917,956
Total shareholders’ equity	2,786,571	2,713,097
Total liabilities and shareholders’ equity	$ 5,287,128	$ 5,123,672

Condensed Consolidated Statemen

Condensed Consolidated Statements Of Income - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Revenues:
Product sales, net	$ 440,847	$ 373,678
Royalties and contract revenues	3,766	2,375
Total revenues	444,613	376,053
Operating expenses:
Cost of product sales (excluding amortization of intangible assets)	33,919	25,065
Selling, general and administrative	207,213	144,255
Research and development	62,667	44,928
Intangible asset amortization	53,007	25,665
Total operating expenses	356,806	239,913
Income from operations	87,807	136,140
Interest expense, net	(20,605)	(18,844)
Foreign exchange loss	(1,728)	(1,464)
Income before income tax provision and equity in loss of investees	65,474	115,832
Income tax provision	19,146	29,160
Equity in loss of investees	337	161
Net income	$ 45,991	$ 86,511
Net income per ordinary share:
Basic (in dollars per share)	$ 0.77	$ 1.44
Diluted (in dollars per share)	$ 0.75	$ 1.41
Weighted-average ordinary shares used in per share calculations - basic (in shares)	59,928	59,880
Weighted-average ordinary shares used in per share calculations - diluted (in shares)	61,178	61,178

Condensed Consolidated Stateme4

Condensed Consolidated Statements Of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Statement of Comprehensive Income [Abstract]
Net income	$ 45,991	$ 86,511
Other comprehensive income (loss):
Foreign currency translation adjustments	38,853	18,112
Unrealized gain (loss) on hedging activities, net of tax expense (benefit) of $458 and $(89), respectively	3,204	(622)
Other comprehensive income	42,057	17,490
Total comprehensive income	$ 88,048	$ 104,001

Condensed Consolidated Stateme5

Condensed Consolidated Statements Of Comprehensive Income (Parenthetical) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Statement of Comprehensive Income [Abstract]
Tax expense (benefit) on hedging activities	$ 458	$ (89)

Condensed Consolidated Stateme6

Condensed Consolidated Statements Of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Operating activities
Net income	$ 45,991	$ 86,511
Adjustments to reconcile net income to net cash provided by operating activities:
Intangible asset amortization	53,007	25,665
Share-based compensation	24,303	25,193
Depreciation	3,722	3,130
Loss on disposal of property, plant and equipment	256	82
Deferred income taxes	(15,307)	(15,000)
Provision for losses on accounts receivable and inventory	590	948
Amortization of debt discount and deferred financing costs	10,617	5,615
Other non-cash transactions	16,026	1,405
Changes in assets and liabilities:
Accounts receivable	(56,591)	(8,483)
Inventories	(3,312)	(4,258)
Prepaid expenses and other current assets	(3,534)	(10,637)
Other long-term assets	(3,988)	(2,170)
Accounts payable	23,136	5,865
Accrued liabilities	47,484	(15,743)
Income taxes payable	14,183	30,753
Deferred revenue	(1,875)	27,490
Other non-current liabilities	7,651	8,174
Net cash provided by operating activities	162,359	164,540
Investing activities
Purchases of property, plant and equipment	(7,149)	(3,574)
Acquisition of investments	(235,000)	(60,000)
Proceeds from maturity of investments	195,000	60,000
Net cash used in investing activities	(47,149)	(3,574)
Financing activities
Proceeds from employee equity incentive and purchase plans	10,588	5,676
Repayments of long-term debt	(9,023)	(9,023)
Payment of employee withholding taxes related to share-based awards	(14,594)	(14,431)
Share repurchases	(34,546)	(13,896)
Repayments under revolving credit facility	0	(150,000)
Net cash used in financing activities	(47,575)	(181,674)
Effect of exchange rates on cash and cash equivalents	(501)	1,740
Net increase (decrease) in cash and cash equivalents	67,134	(18,968)
Cash and cash equivalents, at beginning of period	386,035	365,963
Cash and cash equivalents, at end of period	$ 453,169	$ 346,995

The Company and Summary of Sign

The Company and Summary of Significant Accounting Policies	3 Months Ended
	Mar. 31, 2018
Accounting Policies [Abstract]
The Company and Summary of Significant Accounting Policies	The Company and Summary of Significant Accounting Policies Jazz Pharmaceuticals plc is an international biopharmaceutical company focused on improving patients’ lives by identifying, developing and commercializing meaningful products that address unmet medical needs. We have a diverse portfolio of products and product candidates, with a focus in the areas of sleep and hematology/oncology. Our lead marketed products are: • Xyrem ® (sodium oxybate) oral solution , the only product approved by the U.S. Food and Drug Administration, or FDA, and marketed in the U.S. for the treatment of both cataplexy and excessive daytime sleepiness in patients with narcolepsy; • Erwinaze ® (asparaginase Erwinia chrysanthemi ) , a treatment approved in the U.S. and in certain markets in Europe (where it is marketed as Erwinase ® ) for patients with acute lymphoblastic leukemia who have developed hypersensitivity to E. coli -derived asparaginase; • Defitelio ® (defibrotide sodium) , a product approved in the U.S. for the treatment of adult and pediatric patients with hepatic veno-occlusive disease, or VOD, also known as sinusoidal obstruction syndrome with renal or pulmonary dysfunction following hematopoietic stem cell transplantation, or HSCT, and in Europe (where it is marketed as Defitelio ® (defibrotide)) for the treatment of severe VOD in adults and children undergoing HSCT therapy; and • Vyxeos ® (daunorubicin and cytarabine) liposome for injection , a product approved in the U.S. for the treatment of adults with newly-diagnosed therapy-related acute myeloid leukemia or acute myeloid leukemia with myelodysplasia-related changes. Our strategy is to create shareholder value by: • Growing sales of the existing products in our portfolio, including by identifying and investing in growth opportunities such as new treatment indications and new geographic markets; • Acquiring or licensing rights to clinically meaningful and differentiated products on the market or product candidates at various stages of development; and • Pursuing targeted development of post-discovery differentiated product candidates. We apply a disciplined approach to allocating our resources between investments in our current commercial and development portfolio and acquisitions or in-licensing of new assets. Throughout this report, unless otherwise indicated or the context otherwise requires, all references to “Jazz Pharmaceuticals,” “the registrant,” “we,” “us,” and “our” refer to Jazz Pharmaceuticals plc and its consolidated subsidiaries. Throughout this report, all references to “ordinary shares” refer to Jazz Pharmaceuticals plc’s ordinary shares. Basis of Presentation These unaudited condensed consolidated financial statements have been prepared following the requirements of the U.S. Securities and Exchange Commission for interim reporting. As permitted under those rules, certain footnotes and other financial information that are normally required by U.S. generally accepted accounting principles, or U.S. GAAP, can be condensed or omitted. The information included in this Quarterly Report on Form 10-Q should be read in conjunction with our annual consolidated financial statements and accompanying notes included in our Annual Report on Form 10-K for the year ended December 31, 2017 . In the opinion of management, these condensed consolidated financial statements have been prepared on the same basis as the annual consolidated financial statements and include all adjustments, consisting only of normal recurring adjustments, considered necessary for the fair presentation of our financial position and operating results. The results for the three months ended March 31, 2018 are not necessarily indicative of the results to be expected for the year ending December 31, 2018 , for any other interim period or for any future period. Except for the revenue recognition accounting policy that was updated as a result of adopting ASU No. 2014-09, “Revenue from Contracts with Customers”, or ASU No. 2014-09, our significant accounting policies have not changed substantially from those previously described in our Annual Report on Form 10-K for the year ended December 31, 2017 . These condensed consolidated financial statements include the accounts of Jazz Pharmaceuticals plc and our subsidiaries, and intercompany transactions and balances have been eliminated. Our operating segment is reported in a manner consistent with the internal reporting provided to the chief operating decision maker, or CODM. Our CODM has been identified as our chief executive officer. We have determined that we operate in one business segment, which is the identification, development and commercialization of meaningful pharmaceutical products that address unmet medical needs. Use of Estimates The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets, liabilities, revenues and expenses, and related disclosures in the condensed consolidated financial statements and accompanying notes. Management bases its estimates on historical experience and on assumptions believed to be reasonable under the circumstances. Actual results could differ materially from those estimates. Adoption of New Accounting Standards In May 2014, the Financial Accounting Standards Board, or FASB, issued ASU No. 2014-09. The standard states that an entity should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. To achieve this, an entity will need to identify the contract with a customer; identify the separate performance obligations in the contract; determine the transaction price; allocate the transaction price to the separate performance obligations in the contract; and recognize revenue when (or as) the entity satisfies each performance obligation. We adopted ASU No. 2014-09 on January 1, 2018 on a modified retrospective basis. The adoption of ASU No. 2014-09 did not have a material impact on our results of operations and financial position as the timing of revenue recognition for product sales, net, which is our primary revenue stream, did not change. Please see Note 12 for revenue-related disclosures. In August 2016, the FASB issued ASU No. 2016-15, “Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments”. ASU No. 2016-15 addresses how certain cash receipts and cash payments are presented and classified in the statement of cash flows. We adopted this standard on January 1, 2018 and adoption did not have a material impact on our consolidated financial statements. In October 2016, the FASB issued ASU No. 2016-16, “Income Taxes (Topic 740): Intra-Entity Transfers of Assets Other Than Inventory” which requires an entity to recognize the income tax consequences of an intra-entity asset transfer, other than an intra-entity asset transfer of inventory, when the transfer occurs. We adopted this standard on January 1, 2018 on a modified retrospective basis and adoption did not have a material impact on our consolidated financial statements. In January 2017, the FASB issued ASU No. 2017-01, “Business Combinations (Topic 805): Clarifying the Definition of a Business” which provides clarification on the definition of a business and adds guidance to assist entities with evaluating whether transactions should be accounted for as acquisitions (or disposals) of assets or businesses. We adopted this standard on January 1, 2018. The impact of ASU No. 2017-01 will be dependent upon the nature of our future acquisition or disposition transactions, if any. In August 2017, the FASB issued ASU No. 2017-12, “Derivatives and Hedging (Topic 815): Targeted Improvements to Accounting for Hedging Activities”. ASU No. 2017-12 amends and simplifies existing guidance in order to allow companies to more accurately present the economic effects of risk management activities in their financial statements. ASU No. 2017-12 is effective for reporting periods beginning after December 15, 2018, with early adoption permitted. We elected to early adopt this standard on January 1, 2018 on a modified retrospective basis. Adoption of this standard did not have a material impact on our consolidated financial statements. The cumulative effect of the changes made to our consolidated balance sheet as of January 1, 2018 for the adoption of the above accounting standards was as follows (in thousands): Balance at December 31, 2017 Transition Adjustments Balance at January 1, Assets: Deferred tax assets, net $ 34,559 $ 595 $ 35,154 Liabilities: Deferred revenue 8,618 (1,120 ) 7,498 Deferred revenue, non-current 16,115 (1,120 ) 14,995 Deferred tax liabilities, net 383,472 3,133 386,605 Shareholders' Equity: Accumulated other comprehensive loss (140,878 ) 53 (140,825 ) Retained earnings 917,956 (351 ) 917,605 Revenue Recognition Our revenue comprises product sales, net and royalty and contract revenues. Revenues are recognized when control of the promised goods or services is transferred to our customers, in an amount that reflects the consideration we expect to be entitled to in exchange for those goods or services. Prior to recognizing revenue, we make estimates of the transaction price, including variable consideration that is subject to a constraint. Amounts of variable consideration are included in the transaction price to the extent that it is probable that a significant reversal in the amount of cumulative revenue recognized will not occur when the uncertainty associated with the variable consideration is subsequently resolved. Product Sales, Net Product sales revenue is recognized when control has transferred to the customer, which occurs at a point in time, which is typically on delivery to the customer or, in the case of products that are subject to consignment agreements, when the customer removes product from our consigned inventory location for shipment directly to a patient. Reserves for Variable Consideration Revenues from sales of products are recorded at the net sales price, which includes estimates of variable consideration for which reserves are established and which relate to returns, specialty distributor fees, wholesaler fees, prompt payment discounts, government rebates, government chargebacks, coupon programs and rebates under managed care plans. Calculating certain of these reserves involves estimates and judgments and we determine their expected value based on sales or invoice data, contractual terms, historical utilization rates, new information regarding changes in these programs’ regulations and guidelines that would impact the amount of the actual rebates, our expectations regarding future utilization rates for these programs and channel inventory data. These reserves reflect our best estimates of the amount of consideration to which we are entitled based on the terms of the contract. The amount of variable consideration that is included in the transaction price may be constrained, and is included in the net sales price only to the extent that it is probable that a significant reversal in the amount of the cumulative revenue recognized will not occur in a future period. We reassess our reserves for variable consideration at each reporting date. Historically, adjustments to estimates for these reserves have not been material. Reserves for returns, specialty distributor fees, wholesaler fees, government rebates, coupon programs and rebates under managed care plans are included within current liabilities in our condensed consolidated balance sheets. Reserves for government chargebacks and prompt payment discounts are shown as a reduction in accounts receivable. Royalties and Contract Revenues We enter into out-licensing agreements under which we license certain rights to our products or product candidates to third parties. If a licensing arrangement includes multiple goods or services, we consider whether the license is distinct. If the license to our intellectual property is determined to be distinct from the other performance obligations identified in the arrangement, we recognize revenue from non-refundable, upfront fees allocated to the license when the license is transferred to the licensee and the licensee is able to use and benefit from the license. If the license to our intellectual property is determined not to be distinct, it is combined with other goods or services into a combined performance obligation. We consider whether the combined performance obligation is satisfied over time or at a point in time and, if over time, the appropriate method of measuring progress for purposes of recognizing revenue from non-refundable, upfront fees. We evaluate the measure of progress each reporting date and, if necessary, adjust the measure of performance and related revenue recognition. At the inception of each arrangement that includes development milestone payments, we evaluate whether the milestones are considered probable of being reached and estimate the amount to be included in the transaction price using the most likely amount method. If it is probable that a significant revenue reversal would not occur, the associated milestone value is included in the transaction price. Milestone payments that are not within our control or that of the licensee, such as regulatory approvals, are not considered probable of being achieved until those approvals are received. The transaction price is allocated to each performance obligation on a relative stand-alone selling price basis, for which we recognize revenue as or when the performance obligations under the contract are satisfied. At the end of each subsequent reporting period, we re-evaluate the probability of achievement of such development milestones and any related constraint, and if necessary, adjust our estimate of the overall transaction price. For arrangements that include sales-based royalties and milestone payments based on the level of sales, and the license is deemed to be the predominant item to which the royalties and sales-based milestones relate, we recognize revenue at the later of (i) when the related sales occur, or (ii) when the performance obligation to which some or all of the royalty or sales-based milestone has been allocated has been satisfied (or partially satisfied). Significant Risks and Uncertainties Our financial results are significantly influenced by sales of Xyrem. Our ability to maintain or increase Xyrem product sales is subject to a number of risks and uncertainties, including, without limitation, the potential U.S. introduction of a generic version of Xyrem before the entry dates specified in our settlements with certain abbreviated new drug application, or ANDA, filers or on terms that are different from those contemplated by the settlement agreements; the potential U.S. introduction of new products that compete with, or otherwise disrupt the market for, Xyrem in the treatment of cataplexy and/or excessive daytime sleepiness in narcolepsy; ongoing patent litigation and related proceedings or the possibility of new ANDA filers and challenges; changes to or uncertainties around regulatory restrictions, including, among other things, changes to our Xyrem risk evaluation and mitigation strategy, or REMS; changes in healthcare laws and policy, including changes in requirements for patient assistance programs, rebates, reimbursement and coverage by federal healthcare programs, and changes resulting from increased scrutiny on pharmaceutical pricing and REMS programs by government entities; operational disruptions at the Xyrem central pharmacy or any failure to comply with our REMS obligations to the satisfaction of the FDA; and continued acceptance of Xyrem by physicians and patients. In addition to risks related specifically to Xyrem, we are subject to other challenges and risks specific to our business and our ability to execute on our strategy, as well as risks and uncertainties common to companies in the pharmaceutical industry with development and commercial operations, including, without limitation, risks and uncertainties associated with: effectively commercializing our other products and product candidates; pharmaceutical product development and the inherent uncertainty of clinical success; the regulatory approval process; the challenges of protecting and enhancing our intellectual property rights; our dependence on sole source suppliers for most of our products, including the risk of delays or problems in the supply or manufacture of our products and product candidates; competition; complying with applicable regulatory requirements; changes in healthcare laws and policy and related reforms; government investigations and other actions; obtaining and maintaining appropriate pricing and reimbursement for our products; business combination or product or product candidate acquisition transactions; and possible restrictions on our ability and flexibility to pursue certain future opportunities as a result of our substantial outstanding debt obligations. Concentrations of Risk Financial instruments that potentially subject us to concentrations of credit risk consist of cash, cash equivalents, investments and derivative contracts. Our investment policy permits investments in U.S. federal government and federal agency securities, corporate bonds or commercial paper issued by U.S. corporations, money market instruments, certain qualifying money market mutual funds, certain repurchase agreements, and tax-exempt obligations of U.S. states, agencies and municipalities and places restrictions on credit ratings, maturities, and concentration by type and issuer. We are exposed to credit risk in the event of a default by the financial institutions holding our cash, cash equivalents and investments to the extent recorded on the balance sheet. We manage our foreign currency transaction risk and interest rate risk within specified guidelines through the use of derivatives. All of our derivative instruments are utilized for risk management purposes, and we do not use derivatives for speculative trading purposes. As of March 31, 2018 , we had foreign exchange forward contracts with notional amounts totaling $186.5 million . As of March 31, 2018 , the net liability fair value of outstanding foreign exchange forward contracts was $0.2 million . As of March 31, 2018 , we had interest rate swap contracts with notional amounts totaling $300.0 million . These outstanding interest rate swap contracts had a net asset fair value of $5.4 million as of March 31, 2018 . The counterparties to these contracts are large multinational commercial banks, and we believe the risk of nonperformance is not material. We are also subject to credit risk from our accounts receivable related to our product sales. We monitor our exposure within accounts receivable and record a reserve against uncollectible accounts receivable as necessary. We extend credit to pharmaceutical wholesale distributors and specialty pharmaceutical distribution companies, primarily in the U.S., and to other international distributors and hospitals. Customer creditworthiness is monitored and collateral is not required. We monitor deteriorating economic conditions in certain European countries which may result in variability of the timing of cash receipts and an increase in the average length of time that it takes to collect accounts receivable outstanding. Historically, we have not experienced significant credit losses on our accounts receivable and as of March 31, 2018 and December 31, 2017, allowances on receivables were not material. As of March 31, 2018 , five customers accounted for 93% of gross accounts receivable, including Express Scripts Specialty Distribution Services, Inc. and its affiliates, or Express Scripts, which accounted for 72% of gross accounts receivable, and McKesson Corporation and affiliates, or McKesson, which accounted for 19% of gross accounts receivable. We depend on single source suppliers for most of our products, product candidates and their active pharmaceutical ingredients, or APIs. With respect to Xyrem, the API is manufactured for us by a single source supplier and the finished product is manufactured both by us in our facility in Athlone, Ireland and by our U.S.-based Xyrem supplier. Recent Accounting Pronouncements In January 2017, the FASB issued ASU No. 2017-04, “Intangibles - Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment” which simplifies the accounting for goodwill impairment by eliminating Step 2 of the current goodwill impairment test. Goodwill impairment will now be the amount by which the reporting unit’s carrying value exceeds its fair value, limited to the carrying value of the goodwill. The standard is effective for us beginning January 1, 2020. Early adoption is permitted for any impairment tests performed after January 1, 2017. The new guidance is not expected to have a material impact on our results of operations and financial position. In February 2016, the FASB issued ASU No. 2016-02, “Leases (Topic 842)”. Under the new guidance, lessees will be required to recognize a right-of-use asset, which represents the lessee’s right to use, or control the use of, a specified asset for the lease term, and a corresponding lease liability, which represents the lessee’s obligation to make lease payments under a lease, measured on a discounted basis. ASU No. 2016-02 is effective beginning January 1, 2019 and early adoption is permitted. ASU No. 2016-02 must be adopted on a modified retrospective transition basis for leases existing at, or entered into after, the beginning of the earliest comparative period presented in the consolidated financial statements. The adoption of ASU No. 2016-02 will result in a significant increase in our consolidated balance sheet for right-of-use assets and lease liabilities. While we are continuing to assess all potential impacts of the standard, we currently believe the most significant impact relates to our accounting for the lease agreements we entered into in January 2015 and September 2017 to lease office space located in Palo Alto, California in buildings constructed or to be constructed by the landlord, which are accounted for as build-to-suit arrangements under existing accounting standards, and the lease agreement we entered into in August 2016 for office space in Dublin, Ireland. The future minimum lease payments under these leases at March 31, 2018 were $213.9 million .

Cash and Available-for-Sale Sec

Cash and Available-for-Sale Securities	3 Months Ended
	Mar. 31, 2018
Investments, Debt and Equity Securities [Abstract]
Cash and Available-for-Sale Securities	Cash and Available-for-Sale Securities Cash, cash equivalents and investments consisted of the following (in thousands): March 31, 2018 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value Cash and Cash Equivalents Investments Cash $ 136,883 $ — $ — $ 136,883 $ 136,883 $ — Time deposits 390,000 — — 390,000 135,000 255,000 Money market funds 181,286 — — 181,286 181,286 — Totals $ 708,169 $ — $ — $ 708,169 $ 453,169 $ 255,000 December 31, 2017 Amortized Gross Gross Estimated Cash and Cash Investments Cash $ 225,235 $ — $ — $ 225,235 $ 225,235 $ — Time deposits 235,000 — — 235,000 20,000 215,000 Money market funds 140,800 — — 140,800 140,800 — Totals $ 601,035 $ — $ — $ 601,035 $ 386,035 $ 215,000 Cash equivalents and investments are considered available-for-sale securities. We use the specific-identification method for calculating realized gains and losses on securities sold and include them in interest expense, net in the condensed consolidated statements of income. Our investment balances represent time deposits with original maturities of greater than three months and less than one year.

Fair Value Measurement

Fair Value Measurement	3 Months Ended
	Mar. 31, 2018
Fair Value Disclosures [Abstract]
Fair Value Measurement	Fair Value Measurement The following table summarizes, by major security type, our available-for-sale securities and derivative contracts as of March 31, 2018 and December 31, 2017 that were measured at fair value on a recurring basis and were categorized using the fair value hierarchy (in thousands): March 31, 2018 December 31, 2017 Quoted Significant Total Quoted Significant Total Assets: Available-for-sale securities: Time deposits $ — $ 390,000 $ 390,000 $ — $ 235,000 $ 235,000 Money market funds 181,286 — 181,286 140,800 — 140,800 Interest rate contracts — 5,416 5,416 — 2,138 2,138 Foreign exchange forward contracts — 907 907 — 15,495 15,495 Totals $ 181,286 $ 396,323 $ 577,609 $ 140,800 $ 252,633 $ 393,433 Liabilities: Interest rate contracts $ — $ — $ — $ — $ 392 $ 392 Foreign exchange forward contracts — 1,120 1,120 — 5,017 5,017 Totals $ — $ 1,120 $ 1,120 $ — $ 5,409 $ 5,409 As of March 31, 2018 , our available-for-sale securities included time deposits and money market funds and their carrying values were approximately equal to their fair values. Time deposits were measured at fair value using Level 2 inputs and money market funds were measured using quoted prices in active markets, which represent Level 1 inputs. Level 2 inputs, obtained from various third party data providers, represent quoted prices for similar assets in active markets, or these inputs were derived from observable market data, or if not directly observable, were derived from or corroborated by other observable market data. Our derivative assets and liabilities include interest rate and foreign exchange derivatives that are measured at fair value using observable market inputs such as forward rates, interest rates, our own credit risk as well as an evaluation of our counterparties’ credit risks. Based on these inputs, the derivative assets and liabilities are classified within Level 2 of the fair value hierarchy. There were no transfers between the different levels of the fair value hierarchy in 2018 or in 2017 . As of March 31, 2018 , the estimated fair values of our 1.875% exchangeable senior notes due 2021, or the 2021 Notes, and our 1.50% exchangeable senior notes due 2024, or the 2024 Notes, were approximately $602 million and $561 million , respectively. The fair values of the 2021 Notes and the 2024 Notes, which we refer to together as the Exchangeable Senior Notes, were estimated using quoted market prices obtained from brokers (Level 2). The estimated fair value of our borrowing under our term loan was approximately equal to its book value based on the borrowing rates currently available for variable rate loans (Level 2).

Derivative Instruments and Hedg

Derivative Instruments and Hedging Activities	3 Months Ended
	Mar. 31, 2018
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Instruments and Hedging Activities	Derivative Instruments and Hedging Activities We are exposed to certain risks arising from operating internationally, including fluctuations in interest rates on our outstanding term loan borrowings and fluctuations in foreign exchange rates primarily related to the translation of euro-denominated net monetary liabilities, including intercompany balances, held by subsidiaries with a U.S. dollar functional currency. We manage these exposures within specified guidelines through the use of derivatives. All of our derivative instruments are utilized for risk management purposes, and we do not use derivatives for speculative trading purposes. To achieve a desired mix of floating and fixed interest rates on our variable rate debt, we entered into interest rate swap agreements in March 2017 which are effective from March 3, 2017 until July 12, 2021. These agreements hedge contractual term loan interest rates. As of March 31, 2018 and December 31, 2017 , the interest rate swap agreements had a notional amount of $300.0 million . As a result of these agreements, the interest rate on a portion of our term loan borrowings was fixed at 1.895% , plus the borrowing spread, until July 12, 2021 . The effective portion of changes in the fair value of derivatives designated as and that qualify as cash flow hedges is recorded in accumulated other comprehensive loss and is subsequently reclassified into earnings in the period that the hedged forecasted transaction affects earnings. The impact on accumulated other comprehensive loss and earnings from derivative instruments that qualified as cash flow hedges for the three months ended March 31, 2018 and 2017 was as follows (in thousands): Three Months Ended Interest Rate Contracts: 2018 2017 Gain (loss) recognized in accumulated other comprehensive loss, net of tax $ 3,037 $ (855 ) Loss reclassified from accumulated other comprehensive loss to interest expense, net of tax 167 233 A ssuming no change in LIBOR-based interest rates from market rates as of March 31, 2018 , $0.6 million of gains recognized in accumulated other comprehensive loss will be reclassified to earnings over the next 12 months. We enter into foreign exchange forward contracts, with durations of up to 12 months , designed to limit the exposure to fluctuations in foreign exchange rates related to the translation of certain non-U.S. dollar denominated liabilities, including intercompany balances. Hedge accounting is not applied to these derivative instruments as gains and losses on these hedge transactions are designed to offset gains and losses on underlying balance sheet exposures. As of March 31, 2018 and December 31, 2017 , the notional amount of foreign exchange contracts where hedge accounting is not applied was $186.5 million and $98.7 million , respectively. The foreign exchange loss in our condensed consolidated statements of income included gains of $3.8 million associated with foreign exchange contracts not designated as hedging instruments for the three months ended March 31, 2018 . The cash flow effects of our derivative contracts for the three months ended March 31, 2018 and 2017 are included within net cash provided by operating activities in the condensed consolidated statements of cash flows. The following tables summarize the fair value of outstanding derivatives (in thousands): March 31, 2018 Asset Derivatives Liability Derivatives Balance Sheet Location Fair Value Balance Sheet Location Fair Value Derivatives designated as hedging instruments: Interest rate contracts Other current assets $ 706 Accrued liabilities $ — Other non-current assets 4,710 Derivatives not designated as hedging instruments: Foreign exchange forward contracts Other current assets 907 Accrued liabilities 1,120 Total fair value of derivative instruments $ 6,323 $ 1,120 December 31, 2017 Asset Derivatives Liability Derivatives Balance Sheet Location Fair Value Balance Sheet Location Fair Value Derivatives designated as hedging instruments: Interest rate contracts Other non-current assets $ 2,138 Accrued liabilities $ 392 Derivatives not designated as hedging instruments: Foreign exchange forward contracts Other current assets 15,495 Accrued liabilities 5,017 Total fair value of derivative instruments $ 17,633 $ 5,409 Although we do not offset derivative assets and liabilities within our condensed consolidated balance sheets, our International Swap and Derivatives Association agreements provide for net settlement of transactions that are due to or from the same counterparty upon early termination of the agreement due to an event of default or other termination event. The following tables summarize the potential effect on our condensed consolidated balance sheets of offsetting our interest rate contracts and foreign exchange forward contracts subject to such provisions (in thousands): March 31, 2018 Gross Amounts of Recognized Assets/ Liabilities Gross Amounts Offset in the Consolidated Balance Sheet Net Amounts of Assets/ Liabilities Presented in the Consolidated Balance Sheet Gross Amounts Not Offset in the Consolidated Balance Sheet Description Derivative Financial Instruments Cash Collateral Received (Pledged) Net Amount Derivative assets $ 2,711 $ — $ 2,711 $ (71 ) $ — $ 2,640 Derivative liabilities (71 ) — (71 ) 71 — — December 31, 2017 Gross Amounts of Recognized Assets/ Liabilities Gross Amounts Offset in the Consolidated Balance Sheet Net Amounts of Assets/ Liabilities Presented in the Consolidated Balance Sheet Gross Amounts Not Offset in the Consolidated Balance Sheet Description Derivative Financial Instruments Cash Collateral Received (Pledged) Net Amount Derivative assets $ 1,639 $ — $ 1,639 $ (875 ) $ — $ 764 Derivative liabilities (875 ) — (875 ) 875 — —

Inventories

Inventories	3 Months Ended
	Mar. 31, 2018
Inventory Disclosure [Abstract]
Inventories	Inventories Inventories consisted of the following (in thousands): March 31, December 31, Raw materials $ 5,083 $ 3,542 Work in process 21,238 15,692 Finished goods 20,063 24,011 Total inventories $ 46,384 $ 43,245

Goodwill and Intangible Assets

Goodwill and Intangible Assets	3 Months Ended
	Mar. 31, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Intangible Assets	Goodwill and Intangible Assets The gross carrying amount of goodwill was as follows (in thousands): Balance at December 31, 2017 $ 947,537 Foreign exchange 12,972 Balance at March 31, 2018 $ 960,509 The gross carrying amounts and net book values of our intangible assets were as follows (in thousands): March 31, 2018 December 31, 2017 Remaining Gross Accumulated Net Book Gross Accumulated Net Book Acquired developed technologies 14.6 $ 3,426,056 $ (625,755 ) $ 2,800,301 $ 3,392,832 $ (562,473 ) $ 2,830,359 Manufacturing contracts — 13,192 (13,192 ) — 12,824 (12,634 ) 190 Trademarks — 2,918 (2,918 ) — 2,910 (2,910 ) — Total finite-lived intangible assets 3,442,166 (641,865 ) 2,800,301 3,408,566 (578,017 ) 2,830,549 Acquired IPR&D assets 152,845 — 152,845 148,578 — 148,578 Total intangible assets $ 3,595,011 $ (641,865 ) $ 2,953,146 $ 3,557,144 $ (578,017 ) $ 2,979,127 The increase in the gross carrying amount of intangible assets as of March 31, 2018 compared to December 31, 2017 reflected the positive impact of foreign currency translation adjustments, which was due to the strengthening of the euro against the U.S. dollar. The assumptions and estimates used to determine future cash flows and remaining useful lives of our intangible and other long-lived assets are complex and subjective. They can be affected by various factors, including external factors, such as industry and economic trends, and internal factors such as changes in our business strategy and our forecasts for specific product lines. Based on finite-lived intangible assets recorded as of March 31, 2018 , and assuming the underlying assets will not be impaired and that we will not change the expected lives of the assets, future amortization expenses were estimated as follows (in thousands): Year Ending December 31, Estimated Amortization Expense 2018 (remainder) $ 158,964 2019 211,923 2020 208,917 2021 207,837 2022 207,083 Thereafter 1,805,577 Total $ 2,800,301

Certain Balance Sheet Items

Certain Balance Sheet Items	3 Months Ended
	Mar. 31, 2018
Certain Balance Sheet Items [Abstract]
Certain Balance Sheet Items	Certain Balance Sheet Items Property, plant and equipment consisted of the following (in thousands): March 31, December 31, Build-to-suit facility $ 52,222 $ 51,721 Land and buildings 46,857 46,729 Leasehold improvements 29,491 28,779 Construction-in-progress 27,820 21,738 Manufacturing equipment and machinery 24,794 23,586 Computer software 19,391 19,969 Computer equipment 12,481 12,814 Furniture and fixtures 6,739 5,947 Subtotal 219,795 211,283 Less accumulated depreciation and amortization (40,875 ) (41,203 ) Property, plant and equipment, net $ 178,920 $ 170,080 Accrued liabilities consisted of the following (in thousands): March 31, December 31, Rebates and other sales deductions $ 88,878 $ 81,368 Estimated loss contingency 57,000 — Employee compensation and benefits 40,966 54,930 Royalties 7,050 8,058 Selling and marketing accruals 4,546 3,189 Clinical trial accruals 4,053 2,181 Professional fees 3,597 3,213 Inventory-related accruals 3,223 3,002 Sales returns reserve 3,107 3,651 Accrued interest 2,638 7,297 Derivative instrument liabilities 1,120 5,409 Accrued construction-in-progress 838 2,827 Other 23,528 23,654 Total accrued liabilities $ 240,544 $ 198,779

Debt

Debt	3 Months Ended
	Mar. 31, 2018
Debt Disclosure [Abstract]
Debt	Debt The following table summarizes the carrying amount of our indebtedness (in thousands): March 31, December 31, 2021 Notes $ 575,000 $ 575,000 Unamortized discount and debt issuance costs on 2021 Notes (76,668 ) (81,627 ) 2021 Notes, net 498,332 493,373 2024 Notes 575,000 575,000 Unamortized discount and debt issuance costs on 2024 Notes (153,908 ) (158,680 ) 2024 Notes, net 421,092 416,320 Term loan 662,737 671,345 Total debt 1,582,161 1,581,038 Less current portion 45,117 40,605 Total long-term debt $ 1,537,044 $ 1,540,433 Exchangeable Senior Notes The Exchangeable Senior Notes were issued by Jazz Investments I Limited, or the Issuer, a 100% -owned finance subsidiary of Jazz Pharmaceuticals plc. The Exchangeable Senior Notes are senior unsecured obligations of the Issuer and are fully and unconditionally guaranteed on a senior unsecured basis by Jazz Pharmaceuticals plc. No subsidiary of Jazz Pharmaceuticals plc guaranteed the Exchangeable Senior Notes. Subject to certain local law restrictions on payment of dividends, among other things, and potential negative tax consequences, we are not aware of any significant restrictions on the ability of Jazz Pharmaceuticals plc to obtain funds from the Issuer or Jazz Pharmaceuticals plc’s other subsidiaries by dividend or loan, or any legal or economic restrictions on the ability of the Issuer or Jazz Pharmaceuticals plc’s other subsidiaries to transfer funds to Jazz Pharmaceuticals plc in the form of cash dividends, loans or advances. There is no assurance that in the future such restrictions will not be adopted. As of March 31, 2018 , the carrying values of the equity component of the 2021 Notes and the 2024 Notes, net of equity issuance costs, were $126.9 million and $149.8 million , respectively.

Commitments and Contingencies

Commitments and Contingencies	3 Months Ended
	Mar. 31, 2018
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Indemnification In the normal course of business, we enter into agreements that contain a variety of representations and warranties and provide for general indemnification, including indemnification associated with product liability or infringement of intellectual property rights. Our exposure under these agreements is unknown because it involves future claims that may be made but have not yet been made against us. To date, we have not paid any claims or been required to defend any action related to these indemnification obligations. We have agreed to indemnify our executive officers, directors and certain other employees for losses and costs incurred in connection with certain events or occurrences, including advancing money to cover certain costs, subject to certain limitations. The maximum potential amount of future payments we could be required to make under the indemnification obligations is unlimited; however, we maintain insurance policies that may limit our exposure and may enable us to recover a portion of any future amounts paid. Assuming the applicability of coverage, the willingness of the insurer to assume coverage, and subject to certain retention, loss limits and other policy provisions, we believe the fair value of these indemnification obligations is not significant. Accordingly, we did not recognize any liabilities relating to these obligations as of March 31, 2018 and December 31, 2017 . No assurances can be given that the covering insurers will not attempt to dispute the validity, applicability, or amount of coverage without expensive litigation against these insurers, in which case we may incur substantial liabilities as a result of these indemnification obligations. Lease and Other Commitments Facility Leases. In January 2015, we entered into an agreement to lease office space located in Palo Alto, California in a building subsequently constructed by the landlord. The term of this lease is 12 years from the commencement date as defined in the lease agreement and we have an option to extend the term twice for a period of five years each. We are the deemed owner of the building based on applicable accounting guidance for build-to-suit leases. Accordingly, the landlord’s costs of constructing the building were capitalized on our consolidated balance sheets offset a corresponding financing obligation. We began to occupy this office space in October 2017. As of March 31, 2018 , the total amount of the related financing obligation was $64.4 million , which is classified within current liabilities and non-current liabilities in our condensed consolidated balance sheets. In September 2017, we entered into an agreement to lease office space located in Palo Alto, California in a second building to be constructed by the same landlord. We expect to occupy this office space by the end of 2019. This lease has a term of 12 years from the commencement date as defined in the lease agreement and we have an option to extend the term of the lease twice for a period of 5 years each. We are the deemed owner of the building during the construction period based on applicable accounting guidance for build-to-suit leases. As of March 31, 2018 , we recorded project construction costs of $24.8 million incurred by the landlord as construction-in-progress in property, plant and equipment, net and a corresponding financing obligation in other non-current liabilities in our consolidated balance sheets. We will increase the asset and financing obligation as additional building costs are incurred by the landlord during the construction period. Operating Leases. We have noncancelable operating leases for our office buildings and we are obligated to make payments under noncancelable operating leases for automobiles used by our sales force. Other Commitments. As of March 31, 2018 , we had $74.4 million of noncancelable purchase commitments due within one year, primarily related to agreements with third party manufacturers. Legal Proceedings We are involved in legal proceedings, including the following matters: Xyrem ANDA Litigation. On December 10, 2012, we received a notice of Paragraph IV Patent Certification, or Paragraph IV Certification, from Amneal Pharmaceuticals, Inc., formerly known as Amneal Pharmaceuticals, LLC, or Amneal, that it had submitted an ANDA to the FDA requesting approval to market a generic version of Xyrem. On January 18, 2013, we filed a lawsuit against Amneal in the federal district court of New Jersey, or District Court, alleging that our patents covering Xyrem are infringed or will be infringed by Amneal’s ANDA and seeking a permanent injunction to prevent Amneal from introducing a generic version of Xyrem that would infringe these patents. On November 21, 2013, we received a notice of Paragraph IV Certification from Par Pharmaceutical, Inc., or Par, that it had submitted an ANDA to the FDA requesting approval to market a generic version of Xyrem. On December 27, 2013, we filed a lawsuit against Par in the District Court alleging that our patents covering Xyrem are infringed or will be infringed by Par’s ANDA and seeking a permanent injunction to prevent Par from introducing a generic version of Xyrem that would infringe these patents. In May 2014, the District Court granted a request by Amneal to consolidate its case with the Par case. Additional patents covering Xyrem have been issued since May 2014 and have been listed in the FDA’s publication “Approved Drug Products with Therapeutic Equivalence Evaluations,” or the Orange Book, for Xyrem. Amneal and Par gave us additional notices of Paragraph IV Certifications regarding such patents, and we filed additional lawsuits against Amneal and Par in the District Court alleging that our patents covering Xyrem are infringed or will be infringed by Amneal’s and Par’s ANDAs and seeking a permanent injunction to prevent Amneal and Par from introducing a generic version of Xyrem that would infringe our patents. In August 2016, we and Par stipulated to dismiss claims relating to our patents covering the formulation of Xyrem on the grounds that Par had notified the FDA that it had converted its Paragraph IV Certifications to Paragraph III Patent Certifications, or Paragraph III Certifications. In September 2017, we and Amneal stipulated to dismiss claims relating to certain of our patents covering the formulation of Xyrem on the grounds that Amneal had notified the FDA that it had converted its Paragraph IV Certifications as to these patents to Paragraph III Certifications. On October 30, 2014, we received a notice of Paragraph IV Certification from Teva Pharmaceutical Industries Ltd., formerly known as Watson Laboratories, Inc., or Teva, that it had submitted an ANDA to the FDA requesting approval to market a generic version of Xyrem. On December 11, 2014, we filed a lawsuit against Teva in the District Court alleging that our patents covering Xyrem are or will be infringed by Teva’s ANDA and seeking a permanent injunction to prevent Teva from introducing a generic version of Xyrem that would infringe these patents. In March 2015, Teva moved to dismiss the portion of the case based on our Orange Book-listed REMS patents on the grounds that these patents do not cover patentable subject matter. In November 2015, the District Court administratively terminated this motion to dismiss (without prejudice) pending the outcome of inter partes review, or IPR, proceedings before the Patent Trial and Appeal Board, or PTAB, of the U.S. Patent and Trademark Office relating to the patents that were the subject of Teva’s motion. Since March 2015, we received an additional notice of Paragraph IV Certification from Teva regarding newly issued patents for Xyrem listed in the Orange Book, and we filed an additional lawsuit against Teva in the District Court alleging that our patents covering Xyrem are or will be infringed by Teva’s ANDA and seeking a permanent injunction to prevent Teva from introducing a generic version of Xyrem that would infringe these patents. In April 2015, the District Court issued an order consolidating all then-pending lawsuits against Amneal, Par and Teva into one case. On July 23, 2015, we received a notice of Paragraph IV Certification from Lupin Inc., or Lupin, that it had submitted an ANDA to the FDA requesting approval to market a generic version of Xyrem. On September 2, 2015, we filed a lawsuit in the District Court alleging that our patents covering Xyrem are or will be infringed by Lupin’s ANDA and seeking a permanent injunction to prevent Lupin from introducing a generic version of Xyrem that would infringe our patents. In January, April and June 2016, the District Court issued orders consolidating all of the cases then pending against Amneal, Par, Teva and Lupin into a single case for all purposes. Although no trial date has been set for the consolidated case, discovery is scheduled to conclude in the fourth quarter of 2018, and the trial in this consolidated case could occur as early as later that quarter. As discussed in more detail below, we entered into settlement agreements and related agreements in January 2018 and March 2018 with Par and Teva, respectively; as a result, the remaining parties in the consolidated case are Amneal and Lupin. On November 21, 2017, we received a notice of Paragraph IV Certification from Mallinckrodt Inc., or Mallinckrodt, that it had submitted an ANDA to the FDA requesting approval to market a generic version of Xyrem. On January 2, 2018, we filed a lawsuit in the District Court alleging that our patents covering Xyrem are or will be infringed by Mallinckrodt’s ANDA and seeking a permanent injunction to prevent Mallinckrodt from introducing a generic version of Xyrem that would infringe our patents. We cannot predict whether additional generic manufacturers will file ANDAs and require new patent litigation, the specific timing or outcome of events with respect to the remaining defendants or the impact of developments involving any specific parties or patents on other ongoing proceedings with any ANDA filer. Xyrem ANDA Litigation Settlements. On January 9, 2018, we entered into a settlement agreement and related agreements resolving our patent infringement litigation against Par in the District Court, as well as related discovery proceedings and certain IPR proceedings currently on appeal to the United States Court of Appeals for the Federal Circuit, or Federal Circuit. On January 19, 2018, the District Court approved an order dismissing the litigation. In connection with the settlement, we granted Par the right to sell a limited volume of an authorized generic version of Xyrem, or the Par AG Product, in the U.S. for a term beginning on July 1, 2023, or earlier under certain circumstances, and ending on December 31, 2025, or the Par AG Sales Period. Such circumstances include events related to acceleration of the launch date of the authorized generic version of Xyrem by the first ANDA filer, West-Ward Pharmaceuticals Corp. (a wholly owned subsidiary of Hikma Pharmaceuticals PLC), or West-Ward, under the terms of our settlement with West-Ward, the earlier launch of another party’s authorized generic or generic sodium oxybate product, or a final decision that all unexpired claims of the Xyrem patents are not infringed, invalid and/or unenforceable. The volume of the Par AG Product is limited to an annual amount equal to a low single-digit percentage of Xyrem sales volume during the calendar year preceding the entry date of the Par AG Product. We also granted Par a non-exclusive license under the Xyrem patents to make, have made and market its own generic sodium oxybate product under Par’s ANDA (assuming FDA approval is obtained) effective December 31, 2025, or earlier under certain circumstances. Such circumstances include events related to launch of a generic sodium oxybate product by West-Ward or another party under its ANDA, or a final decision that all unexpired claims of the Xyrem patents are not infringed, invalid and/or unenforceable. If the Par license to market its own generic sodium oxybate product accelerates, then Par will have the option to elect to market the Par AG Product until December 31, 2025, but Par will not be entitled to market the Par AG Product and its own generic sodium oxybate product simultaneously. We are entitled to receive a meaningful royalty on net sales of the Par AG Product over the Par AG Sales Period, as well as payment for the supply of the Par AG Product and reimbursement for a portion of the services costs associated with the operation of the Xyrem REMS and distribution of the Par AG Product. On March 30, 2018, we entered into a settlement agreement resolving our patent infringement litigation against Teva in the District Court. On April 5, 2018, the District Court approved an order dismissing the litigation. In connection with the settlement, we granted Teva a license to manufacture, market and sell its own generic sodium oxybate product on or after December 31, 2025, or earlier depending on the occurrence of certain events. We had previously entered into settlement agreements with four other ANDA filers, including the first filer, West-Ward. The specific terms of all of the settlement agreements are confidential. The settlements do not resolve the consolidated case against Amneal and Lupin, or the case against the most recent ANDA filer, Mallinckrodt, which remain pending. Xyrem Post-Grant Patent Review Matters . In January 2015, certain of the ANDA filers filed petitions for IPR with respect to the validity of six of our seven patents associated with the Xyrem REMS, or REMS patents. The PTAB instituted IPR trials with respect to certain of these petitions. In July 2016, the PTAB issued final decisions that the claims of the six REMS patents are unpatentable. In March 2016, the PTAB partially instituted an IPR on three claims of a seventh REMS patent, declining to review 25 of 28 claims, and in March 2017, the PTAB issued a final decision that the three claims they reviewed are unpatentable. The July 2016 and March 2017 PTAB decisions are part of a consolidated appeal currently pending before the Federal Circuit. If the Federal Circuit upholds the PTAB decisions on appeal, we will not be able to enforce claims the PTAB found unpatentable. On April 24, 2018, the Supreme Court of the United States issued an opinion holding that the PTAB does not have authority to partially review a patent where an IPR petitioner has asked for review of all of the claims. As a result of that ruling, the Federal Circuit is considering how to adjudicate the appeal of the PTAB’s March 2017 decision. We cannot predict whether additional post-grant patent review challenges will be filed by any of the ANDA filers or any other entity, the outcome of any future IPR or other proceeding, the outcome of the appeal of the July 2016 and March 2017 PTAB decisions with respect to the REMS patents or the impact any IPR or other proceeding might have on ongoing ANDA litigation proceedings or other aspects of our Xyrem business. From time to time we are involved in legal proceedings arising in the ordinary course of business. We believe there is no other litigation pending that could have, individually or in the aggregate, a material adverse effect on our results of operations or financial condition. Other Contingencies In May and October 2016 and in February 2017, we received subpoenas from the U.S. Attorney’s Office for the District of Massachusetts requesting documents related to our support of 501(c)(3) organizations that provide financial assistance to Medicare patients, and, for Xyrem, documents concerning the provision of financial assistance to Medicare patients. Other companies have disclosed similar subpoenas and continuing inquiries. We have a comprehensive program intended to ensure our compliance with applicable legal and regulatory requirements for pharmaceutical companies, including guidelines established by the Office of Inspector General of the U.S. Department of Health and Human Services regarding patient assistance programs, and we have been cooperating with the government’s investigation. We have engaged in discussions with the U.S. Department of Justice, or DOJ, about a possible resolution, and in April 2018, we reached an agreement in principle with the DOJ on a proposal for a civil settlement of potential claims by the DOJ in the amount of $57.0 million , subject to accrual of interest on the settlement amount from the date of the agreement in principle, negotiation of a definitive settlement agreement and other contingencies. During the three months ended March 31, 2018 , we recorded $57.0 million related to this matter within accrued liabilities on our condensed consolidated balance sheet with the related expense included in selling, general and administrative expenses on our condensed consolidated statement of income. Material issues remain subject to further negotiation and approval by us and the DOJ before the proposed settlement can be finalized. We cannot provide assurances that our efforts to reach a final settlement with the DOJ will be successful or, if they are, the timing or final terms of any such settlement. Any such settlement could also involve entry into a corporate integrity agreement, which would impose costs and burdens on the operation of our business. If we do not reach a final settlement, the outcome of this investigation could include an enforcement action against us. If the federal government were to file an enforcement action against us as a result of the investigation and could establish the elements of a violation of relevant laws, we could be subject to damages, fines and penalties, which could be substantial, along with other criminal, civil or administrative sanctions, and we would expect to incur significant costs in connection with such enforcement action, regardless of the outcome.

Shareholders' Equity

Shareholders' Equity	3 Months Ended
	Mar. 31, 2018
Stockholders' Equity Note [Abstract]
Shareholders' Equity	Shareholders’ Equity The following tables present a reconciliation of our beginning and ending balances in shareholders’ equity for the three months ended March 31, 2018 and 2017 (in thousands): Total Shareholders' Equity Shareholders' equity at January 1, 2018 $ 2,713,097 Effect of adoption of new accounting standards (298 ) Issuance of ordinary shares in conjunction with employee equity incentive and purchase plans 10,588 Employee withholding taxes related to share-based awards (14,594 ) Share-based compensation 24,276 Shares repurchased (34,546 ) Other comprehensive income 42,057 Net income 45,991 Shareholders' equity at March 31, 2018 $ 2,786,571 Total Shareholders' Equity Shareholders' equity at January 1, 2017 $ 1,877,339 Issuance of ordinary shares in conjunction with employee equity incentive and purchase plans 5,676 Employee withholding taxes related to share-based awards (14,431 ) Share-based compensation 25,297 Shares repurchased (13,896 ) Other comprehensive income 17,490 Net income 86,511 Shareholders' equity at March 31, 2017 $ 1,983,986 Share Repurchase Program In November 2016, our board of directors authorized a share repurchase program pursuant to which we are authorized to repurchase a number of ordinary shares having an aggregate purchase price of up to $300.0 million , exclusive of any brokerage commissions. In the three months ended March 31, 2018 , we spent a total of $34.5 million to purchase 0.2 million of our ordinary shares under the share repurchase program at an average total purchase price, including commissions, of $145.34 per share. As of March 31, 2018 , the remaining amount authorized under the share repurchase program was $148.2 million . Accumulated Other Comprehensive Loss The components of accumulated other comprehensive loss as of March 31, 2018 and December 31, 2017 were as follows (in thousands): Net Unrealized Foreign Total Balance at December 31, 2017 $ 1,482 $ (142,360 ) $ (140,878 ) Effect of adoption of ASU No. 2017-12 53 — 53 Balance at January 1, 2018 1,535 (142,360 ) (140,825 ) Other comprehensive income before reclassifications 3,037 38,853 41,890 Amounts reclassified from accumulated other comprehensive loss 167 — 167 Other comprehensive income, net 3,204 38,853 42,057 Balance at March 31, 2018 $ 4,739 $ (103,507 ) $ (98,768 ) During the three months ended March 31, 2018 , other comprehensive income reflects foreign currency translation adjustments, primarily due to the strengthening of the euro against the U.S. dollar, and the net unrealized gain on derivatives that qualify as cash flow hedges.

Net Income per Ordinary Share

Net Income per Ordinary Share	3 Months Ended
	Mar. 31, 2018
Earnings Per Share [Abstract]
Net Income per Ordinary Share	Net Income per Ordinary Share Basic net income per ordinary share is based on the weighted-average number of ordinary shares outstanding. Diluted net income per ordinary share is based on the weighted-average number of ordinary shares outstanding and potentially dilutive ordinary shares outstanding. Basic and diluted net income per ordinary share were computed as follows (in thousands, except per share amounts): Three Months Ended 2018 2017 Numerator: Net income $ 45,991 $ 86,511 Denominator: Weighted-average ordinary shares used in per share calculations - basic 59,928 59,880 Dilutive effect of employee equity incentive and purchase plans 1,250 1,298 Weighted-average ordinary shares used in per share calculations - diluted 61,178 61,178 Net income per ordinary share: Basic $ 0.77 $ 1.44 Diluted $ 0.75 $ 1.41 Potentially dilutive ordinary shares from our employee equity incentive and purchase plans and the Exchangeable Senior Notes are determined by applying the treasury stock method to the assumed exercise of share options, the assumed vesting of outstanding restricted stock units, or RSUs, the assumed issuance of ordinary shares under our employee stock purchase plan, or ESPP, and the assumed issuance of ordinary shares upon exchange of the Exchangeable Senior Notes. The potential issue of ordinary shares issuable upon exchange of the Exchangeable Senior Notes had no effect on diluted net income per ordinary share because the average price of our ordinary shares for the three months ended March 31, 2018 and 2017 did not exceed the effective exchange prices per ordinary share of the Exchangeable Senior Notes. The following table represents the weighted-average ordinary shares that were excluded from the calculation of diluted net income per ordinary share for the periods presented because including them would have an anti-dilutive effect (in thousands): Three Months Ended 2018 2017 Exchangeable Senior Notes 5,504 2,878 Options to purchase ordinary shares and RSUs 3,279 3,406 Ordinary shares under ESPP 26 —

Revenues

Revenues	3 Months Ended
	Mar. 31, 2018
Revenue from Contract with Customer [Abstract]
Revenues	Revenues The following table presents a summary of total revenues (in thousands): Three Months Ended 2018 2017 Xyrem $ 316,777 $ 272,326 Erwinaze/Erwinase 50,627 51,388 Defitelio/defibrotide 35,061 35,900 Vyxeos 26,228 — Prialt ® (ziconotide) intrathecal infusion 6,126 7,717 Other 6,028 6,347 Product sales, net 440,847 373,678 Royalties and contract revenues 3,766 2,375 Total revenues $ 444,613 $ 376,053 The following table presents a summary of total revenues attributed to geographic sources (in thousands): Three Months Ended 2018 2017 United States $ 405,687 $ 339,183 Europe 28,331 31,352 All other 10,595 5,518 Total revenues $ 444,613 $ 376,053 The following table presents a summary of the percentage of total revenues from customers that represented more than 10% of our total revenues: Three Months Ended 2018 2017 Express Scripts 71 % 72 % McKesson 20 % 17 % Contract Liabilities - Deferred Revenue The deferred revenue balance as of March 31, 2018 primarily related to deferred upfront fees received from Nippon Shinyaku Co., Ltd., or Nippon, in connection with two license, development and commercialization agreements granting Nippon exclusive rights to develop and commercialize each of Defitelio and Vyxeos in Japan. We recognized contract revenues of $1.9 million during the three months ended March 31, 2018 relating to these upfront payments. The deferred revenue balances are being recognized over an average of four years representing the period we expect to perform our research and developments obligations under each agreement. The following table presents a reconciliation of our beginning and ending balances in contract liabilities from contracts with customers for the three months ended March 31, 2018 (in thousands): Contract Liabilities Balance as of December 31, 2017 $ 24,733 Effect of adoption of ASU 2014-09 (2,240 ) Amount recognized within royalties and contract revenues (1,875 ) Balance as of March 31, 2018 $ 20,618

Share-Based Compensation

Share-Based Compensation	3 Months Ended
	Mar. 31, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Share-Based Compensation	Share-Based Compensation Share-based compensation expense related to share options, RSUs and grants under our ESPP was as follows (in thousands): Three Months Ended 2018 2017 Selling, general and administrative $ 18,234 $ 19,805 Research and development 4,375 4,142 Cost of product sales 1,694 1,246 Total share-based compensation expense, pre-tax 24,303 25,193 Income tax benefit from share-based compensation expense (3,668 ) (7,624 ) Total share-based compensation expense, net of tax $ 20,635 $ 17,569 Share Options The table below shows the number of shares underlying options granted to purchase our ordinary shares, the weighted-average assumptions used in the Black-Scholes option pricing model and the resulting weighted-average grant date fair value of share options granted: Three Months Ended 2018 2017 Shares underlying options granted (in thousands) 1,152 1,171 Grant date fair value $ 46.08 $ 42.19 Black-Scholes option pricing model assumption information: Volatility 35 % 35 % Expected term (years) 4.5 4.3 Range of risk-free rates 2.2-2.5% 1.7-1.8% Expected dividend yield — % — % Restricted Stock Units The table below shows the number of RSUs granted covering an equal number of our ordinary shares and the weighted-average grant date fair value of RSUs granted: Three Months Ended 2018 2017 RSUs granted (in thousands) 461 468 Grant date fair value $ 140.60 $ 135.46 The fair value of RSUs is determined on the date of grant based on the market price of our ordinary shares on that date. The fair value of RSUs is expensed ratably over the vesting period, generally over four years . As of March 31, 2018 , compensation cost not yet recognized related to unvested share options and RSUs was $101.6 million and $121.5 million , respectively, which is expected to be recognized over a weighted-average period of 2.9 years and 3.0 years, respectively.

Income Taxes

Income Taxes	3 Months Ended
	Mar. 31, 2018
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes Our income tax provision was $19.1 million in the three months ended March 31, 2018 compared to $29.2 million for the same period in 2017 . The effective tax rate was 29.2% in the three months ended March 31, 2018 compared to 25.2% for the same period in 2017 . The increase in the effective tax rate for the three months ended March 31, 2018 compared to the same period in 2017 was primarily due to the impact of the accrued estimated loss contingency and a decrease in originating tax credits, partially offset by a decrease in the U.S. corporate income tax. The effective tax rate for the three months ended March 31, 2018 was higher than the Irish statutory rate of 12.5% primarily due to various expenses not deductible for income tax purposes, income taxable at a rate higher than the Irish statutory rate and unrecognized tax benefits. We do not provide for Irish income taxes on undistributed earnings of our foreign operations that are intended to be indefinitely reinvested in our foreign subsidiaries. Our net deferred tax liability primarily arose due to the acquisition of Celator Pharmaceuticals, Inc. The balance is net of deferred tax assets which are comprised primarily of U.S. federal and state tax credits, U.S. federal and state and foreign net operating loss carryforwards and other temporary differences. We maintain a valuation allowance against certain foreign and U.S. federal and state deferred tax assets. Each reporting period, we evaluate the need for a valuation allowance on our deferred tax assets by jurisdiction and adjust our estimates as more information becomes available. We are required to recognize the financial statement effects of a tax position when it is more likely than not, based on the technical merits, that the position will be sustained upon examination. As a result, we have recorded an unrecognized tax benefit for certain tax benefits which we judge may not be sustained upon examination. Our most significant tax jurisdictions are Ireland, the U.S. (both at the federal level and in various state jurisdictions), Italy and France. These jurisdictions have statute of limitations ranging from three to five years. However, in the U.S. (at the federal level and in most states), carryforward tax attributes that were generated in 2013 and earlier may still be adjusted upon examination by the tax authorities. Certain of our subsidiaries are currently under examination by the French tax authorities for the years ended December 31, 2012 and 2013. These examinations may lead to ordinary course adjustments or proposed adjustments to our taxes. In December 2015, we received proposed tax assessment notices from the French tax authorities for 2012 and 2013 relating to certain transfer pricing adjustments. The notices propose additional French tax of approximately $47 million , including interest and penalties through the date of the assessment, translated at the foreign exchange rate at March 31, 2018 . We disagree with the proposed assessment and intend to contest it vigorously. For the three months ended March 31, 2018 , we have not recorded any measurement period adjustments to the provisional estimates recorded as of December 31, 2017 in accordance with the SEC’s Staff Accounting Bulletin No. 118, or SAB 118. We will continue to analyze the impact of the U.S. Tax Cuts and Jobs Act under SAB 118 and will record adjustments to provisional amounts as our analyses are refined.

Subsequent Event

Subsequent Event	3 Months Ended
	Mar. 31, 2018
Subsequent Events [Abstract]
Subsequent Events	Subsequent Event On April 30, 2018, we entered into an agreement with Spark Therapeutics, Inc., or Spark, to purchase a rare pediatric disease priority review voucher, or PRV, from Spark. In consideration for the PRV, we will pay Spark $110.0 million upon closing of the transaction, which is subject to customary closing conditions, including expiration or termination of the applicable waiting period under the Hart-Scott-Rodino Antitrust Improvements Act of 1976. As we may use the PRV to obtain priority review by the FDA for one of our future regulatory submissions or may sell or transfer the PRV to a third party, we will capitalize the acquisition cost within intangible assets on our condensed consolidated balance sheet upon closing of the transaction.

The Company and Summary of Si22

The Company and Summary of Significant Accounting Policies (Policies)	3 Months Ended
	Mar. 31, 2018
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation These unaudited condensed consolidated financial statements have been prepared following the requirements of the U.S. Securities and Exchange Commission for interim reporting. As permitted under those rules, certain footnotes and other financial information that are normally required by U.S. generally accepted accounting principles, or U.S. GAAP, can be condensed or omitted. The information included in this Quarterly Report on Form 10-Q should be read in conjunction with our annual consolidated financial statements and accompanying notes included in our Annual Report on Form 10-K for the year ended December 31, 2017 . In the opinion of management, these condensed consolidated financial statements have been prepared on the same basis as the annual consolidated financial statements and include all adjustments, consisting only of normal recurring adjustments, considered necessary for the fair presentation of our financial position and operating results. The results for the three months ended March 31, 2018 are not necessarily indicative of the results to be expected for the year ending December 31, 2018 , for any other interim period or for any future period. Except for the revenue recognition accounting policy that was updated as a result of adopting ASU No. 2014-09, “Revenue from Contracts with Customers”, or ASU No. 2014-09, our significant accounting policies have not changed substantially from those previously described in our Annual Report on Form 10-K for the year ended December 31, 2017 . These condensed consolidated financial statements include the accounts of Jazz Pharmaceuticals plc and our subsidiaries, and intercompany transactions and balances have been eliminated. Our operating segment is reported in a manner consistent with the internal reporting provided to the chief operating decision maker, or CODM. Our CODM has been identified as our chief executive officer. We have determined that we operate in one business segment, which is the identification, development and commercialization of meaningful pharmaceutical products that address unmet medical needs.
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets, liabilities, revenues and expenses, and related disclosures in the condensed consolidated financial statements and accompanying notes. Management bases its estimates on historical experience and on assumptions believed to be reasonable under the circumstances. Actual results could differ materially from those estimates.
Adoption of New Accounting Standards and Recent Accounting Pronouncements	Recent Accounting Pronouncements In January 2017, the FASB issued ASU No. 2017-04, “Intangibles - Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment” which simplifies the accounting for goodwill impairment by eliminating Step 2 of the current goodwill impairment test. Goodwill impairment will now be the amount by which the reporting unit’s carrying value exceeds its fair value, limited to the carrying value of the goodwill. The standard is effective for us beginning January 1, 2020. Early adoption is permitted for any impairment tests performed after January 1, 2017. The new guidance is not expected to have a material impact on our results of operations and financial position. In February 2016, the FASB issued ASU No. 2016-02, “Leases (Topic 842)”. Under the new guidance, lessees will be required to recognize a right-of-use asset, which represents the lessee’s right to use, or control the use of, a specified asset for the lease term, and a corresponding lease liability, which represents the lessee’s obligation to make lease payments under a lease, measured on a discounted basis. ASU No. 2016-02 is effective beginning January 1, 2019 and early adoption is permitted. ASU No. 2016-02 must be adopted on a modified retrospective transition basis for leases existing at, or entered into after, the beginning of the earliest comparative period presented in the consolidated financial statements. The adoption of ASU No. 2016-02 will result in a significant increase in our consolidated balance sheet for right-of-use assets and lease liabilities. While we are continuing to assess all potential impacts of the standard, we currently believe the most significant impact relates to our accounting for the lease agreements we entered into in January 2015 and September 2017 to lease office space located in Palo Alto, California in buildings constructed or to be constructed by the landlord, which are accounted for as build-to-suit arrangements under existing accounting standards, and the lease agreement we entered into in August 2016 for office space in Dublin, Ireland. The future minimum lease payments under these leases at March 31, 2018 were $213.9 million . Adoption of New Accounting Standards In May 2014, the Financial Accounting Standards Board, or FASB, issued ASU No. 2014-09. The standard states that an entity should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. To achieve this, an entity will need to identify the contract with a customer; identify the separate performance obligations in the contract; determine the transaction price; allocate the transaction price to the separate performance obligations in the contract; and recognize revenue when (or as) the entity satisfies each performance obligation. We adopted ASU No. 2014-09 on January 1, 2018 on a modified retrospective basis. The adoption of ASU No. 2014-09 did not have a material impact on our results of operations and financial position as the timing of revenue recognition for product sales, net, which is our primary revenue stream, did not change. Please see Note 12 for revenue-related disclosures. In August 2016, the FASB issued ASU No. 2016-15, “Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments”. ASU No. 2016-15 addresses how certain cash receipts and cash payments are presented and classified in the statement of cash flows. We adopted this standard on January 1, 2018 and adoption did not have a material impact on our consolidated financial statements. In October 2016, the FASB issued ASU No. 2016-16, “Income Taxes (Topic 740): Intra-Entity Transfers of Assets Other Than Inventory” which requires an entity to recognize the income tax consequences of an intra-entity asset transfer, other than an intra-entity asset transfer of inventory, when the transfer occurs. We adopted this standard on January 1, 2018 on a modified retrospective basis and adoption did not have a material impact on our consolidated financial statements. In January 2017, the FASB issued ASU No. 2017-01, “Business Combinations (Topic 805): Clarifying the Definition of a Business” which provides clarification on the definition of a business and adds guidance to assist entities with evaluating whether transactions should be accounted for as acquisitions (or disposals) of assets or businesses. We adopted this standard on January 1, 2018. The impact of ASU No. 2017-01 will be dependent upon the nature of our future acquisition or disposition transactions, if any. In August 2017, the FASB issued ASU No. 2017-12, “Derivatives and Hedging (Topic 815): Targeted Improvements to Accounting for Hedging Activities”. ASU No. 2017-12 amends and simplifies existing guidance in order to allow companies to more accurately present the economic effects of risk management activities in their financial statements. ASU No. 2017-12 is effective for reporting periods beginning after December 15, 2018, with early adoption permitted. We elected to early adopt this standard on January 1, 2018 on a modified retrospective basis. Adoption of this standard did not have a material impact on our consolidated financial statements.
Revenue Recognition	Revenue Recognition Our revenue comprises product sales, net and royalty and contract revenues. Revenues are recognized when control of the promised goods or services is transferred to our customers, in an amount that reflects the consideration we expect to be entitled to in exchange for those goods or services. Prior to recognizing revenue, we make estimates of the transaction price, including variable consideration that is subject to a constraint. Amounts of variable consideration are included in the transaction price to the extent that it is probable that a significant reversal in the amount of cumulative revenue recognized will not occur when the uncertainty associated with the variable consideration is subsequently resolved. Product Sales, Net Product sales revenue is recognized when control has transferred to the customer, which occurs at a point in time, which is typically on delivery to the customer or, in the case of products that are subject to consignment agreements, when the customer removes product from our consigned inventory location for shipment directly to a patient. Reserves for Variable Consideration Revenues from sales of products are recorded at the net sales price, which includes estimates of variable consideration for which reserves are established and which relate to returns, specialty distributor fees, wholesaler fees, prompt payment discounts, government rebates, government chargebacks, coupon programs and rebates under managed care plans. Calculating certain of these reserves involves estimates and judgments and we determine their expected value based on sales or invoice data, contractual terms, historical utilization rates, new information regarding changes in these programs’ regulations and guidelines that would impact the amount of the actual rebates, our expectations regarding future utilization rates for these programs and channel inventory data. These reserves reflect our best estimates of the amount of consideration to which we are entitled based on the terms of the contract. The amount of variable consideration that is included in the transaction price may be constrained, and is included in the net sales price only to the extent that it is probable that a significant reversal in the amount of the cumulative revenue recognized will not occur in a future period. We reassess our reserves for variable consideration at each reporting date. Historically, adjustments to estimates for these reserves have not been material. Reserves for returns, specialty distributor fees, wholesaler fees, government rebates, coupon programs and rebates under managed care plans are included within current liabilities in our condensed consolidated balance sheets. Reserves for government chargebacks and prompt payment discounts are shown as a reduction in accounts receivable. Royalties and Contract Revenues We enter into out-licensing agreements under which we license certain rights to our products or product candidates to third parties. If a licensing arrangement includes multiple goods or services, we consider whether the license is distinct. If the license to our intellectual property is determined to be distinct from the other performance obligations identified in the arrangement, we recognize revenue from non-refundable, upfront fees allocated to the license when the license is transferred to the licensee and the licensee is able to use and benefit from the license. If the license to our intellectual property is determined not to be distinct, it is combined with other goods or services into a combined performance obligation. We consider whether the combined performance obligation is satisfied over time or at a point in time and, if over time, the appropriate method of measuring progress for purposes of recognizing revenue from non-refundable, upfront fees. We evaluate the measure of progress each reporting date and, if necessary, adjust the measure of performance and related revenue recognition. At the inception of each arrangement that includes development milestone payments, we evaluate whether the milestones are considered probable of being reached and estimate the amount to be included in the transaction price using the most likely amount method. If it is probable that a significant revenue reversal would not occur, the associated milestone value is included in the transaction price. Milestone payments that are not within our control or that of the licensee, such as regulatory approvals, are not considered probable of being achieved until those approvals are received. The transaction price is allocated to each performance obligation on a relative stand-alone selling price basis, for which we recognize revenue as or when the performance obligations under the contract are satisfied. At the end of each subsequent reporting period, we re-evaluate the probability of achievement of such development milestones and any related constraint, and if necessary, adjust our estimate of the overall transaction price. For arrangements that include sales-based royalties and milestone payments based on the level of sales, and the license is deemed to be the predominant item to which the royalties and sales-based milestones relate, we recognize revenue at the later of (i) when the related sales occur, or (ii) when the performance obligation to which some or all of the royalty or sales-based milestone has been allocated has been satisfied (or partially satisfied).
Significant Risks and Uncertainties	Significant Risks and Uncertainties Our financial results are significantly influenced by sales of Xyrem. Our ability to maintain or increase Xyrem product sales is subject to a number of risks and uncertainties, including, without limitation, the potential U.S. introduction of a generic version of Xyrem before the entry dates specified in our settlements with certain abbreviated new drug application, or ANDA, filers or on terms that are different from those contemplated by the settlement agreements; the potential U.S. introduction of new products that compete with, or otherwise disrupt the market for, Xyrem in the treatment of cataplexy and/or excessive daytime sleepiness in narcolepsy; ongoing patent litigation and related proceedings or the possibility of new ANDA filers and challenges; changes to or uncertainties around regulatory restrictions, including, among other things, changes to our Xyrem risk evaluation and mitigation strategy, or REMS; changes in healthcare laws and policy, including changes in requirements for patient assistance programs, rebates, reimbursement and coverage by federal healthcare programs, and changes resulting from increased scrutiny on pharmaceutical pricing and REMS programs by government entities; operational disruptions at the Xyrem central pharmacy or any failure to comply with our REMS obligations to the satisfaction of the FDA; and continued acceptance of Xyrem by physicians and patients. In addition to risks related specifically to Xyrem, we are subject to other challenges and risks specific to our business and our ability to execute on our strategy, as well as risks and uncertainties common to companies in the pharmaceutical industry with development and commercial operations, including, without limitation, risks and uncertainties associated with: effectively commercializing our other products and product candidates; pharmaceutical product development and the inherent uncertainty of clinical success; the regulatory approval process; the challenges of protecting and enhancing our intellectual property rights; our dependence on sole source suppliers for most of our products, including the risk of delays or problems in the supply or manufacture of our products and product candidates; competition; complying with applicable regulatory requirements; changes in healthcare laws and policy and related reforms; government investigations and other actions; obtaining and maintaining appropriate pricing and reimbursement for our products; business combination or product or product candidate acquisition transactions; and possible restrictions on our ability and flexibility to pursue certain future opportunities as a result of our substantial outstanding debt obligations.
Concentrations of Risk	Concentrations of Risk Financial instruments that potentially subject us to concentrations of credit risk consist of cash, cash equivalents, investments and derivative contracts. Our investment policy permits investments in U.S. federal government and federal agency securities, corporate bonds or commercial paper issued by U.S. corporations, money market instruments, certain qualifying money market mutual funds, certain repurchase agreements, and tax-exempt obligations of U.S. states, agencies and municipalities and places restrictions on credit ratings, maturities, and concentration by type and issuer. We are exposed to credit risk in the event of a default by the financial institutions holding our cash, cash equivalents and investments to the extent recorded on the balance sheet. We manage our foreign currency transaction risk and interest rate risk within specified guidelines through the use of derivatives. All of our derivative instruments are utilized for risk management purposes, and we do not use derivatives for speculative trading purposes. As of March 31, 2018 , we had foreign exchange forward contracts with notional amounts totaling $186.5 million . As of March 31, 2018 , the net liability fair value of outstanding foreign exchange forward contracts was $0.2 million . As of March 31, 2018 , we had interest rate swap contracts with notional amounts totaling $300.0 million . These outstanding interest rate swap contracts had a net asset fair value of $5.4 million as of March 31, 2018 . The counterparties to these contracts are large multinational commercial banks, and we believe the risk of nonperformance is not material. We are also subject to credit risk from our accounts receivable related to our product sales. We monitor our exposure within accounts receivable and record a reserve against uncollectible accounts receivable as necessary. We extend credit to pharmaceutical wholesale distributors and specialty pharmaceutical distribution companies, primarily in the U.S., and to other international distributors and hospitals. Customer creditworthiness is monitored and collateral is not required. We monitor deteriorating economic conditions in certain European countries which may result in variability of the timing of cash receipts and an increase in the average length of time that it takes to collect accounts receivable outstanding.

The Company and Summary of Si23

The Company and Summary of Significant Accounting Policies (Tables)	3 Months Ended
	Mar. 31, 2018
Accounting Policies [Abstract]
Schedule of New Accounting Pronouncements and Changes in Accounting Principles	The cumulative effect of the changes made to our consolidated balance sheet as of January 1, 2018 for the adoption of the above accounting standards was as follows (in thousands): Balance at December 31, 2017 Transition Adjustments Balance at January 1, Assets: Deferred tax assets, net $ 34,559 $ 595 $ 35,154 Liabilities: Deferred revenue 8,618 (1,120 ) 7,498 Deferred revenue, non-current 16,115 (1,120 ) 14,995 Deferred tax liabilities, net 383,472 3,133 386,605 Shareholders' Equity: Accumulated other comprehensive loss (140,878 ) 53 (140,825 ) Retained earnings 917,956 (351 ) 917,605

Cash and Available-for-Sale S24

Cash and Available-for-Sale Securities (Tables)	3 Months Ended
	Mar. 31, 2018
Investments, Debt and Equity Securities [Abstract]
Cash and Cash Equivalents and Investments	Cash, cash equivalents and investments consisted of the following (in thousands): March 31, 2018 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value Cash and Cash Equivalents Investments Cash $ 136,883 $ — $ — $ 136,883 $ 136,883 $ — Time deposits 390,000 — — 390,000 135,000 255,000 Money market funds 181,286 — — 181,286 181,286 — Totals $ 708,169 $ — $ — $ 708,169 $ 453,169 $ 255,000 December 31, 2017 Amortized Gross Gross Estimated Cash and Cash Investments Cash $ 225,235 $ — $ — $ 225,235 $ 225,235 $ — Time deposits 235,000 — — 235,000 20,000 215,000 Money market funds 140,800 — — 140,800 140,800 — Totals $ 601,035 $ — $ — $ 601,035 $ 386,035 $ 215,000

Fair Value Measurement (Tables)

Fair Value Measurement (Tables)	3 Months Ended
	Mar. 31, 2018
Fair Value Disclosures [Abstract]
Assets and Liabilities Measured at Fair Value on a Recurring Basis	The following table summarizes, by major security type, our available-for-sale securities and derivative contracts as of March 31, 2018 and December 31, 2017 that were measured at fair value on a recurring basis and were categorized using the fair value hierarchy (in thousands): March 31, 2018 December 31, 2017 Quoted Significant Total Quoted Significant Total Assets: Available-for-sale securities: Time deposits $ — $ 390,000 $ 390,000 $ — $ 235,000 $ 235,000 Money market funds 181,286 — 181,286 140,800 — 140,800 Interest rate contracts — 5,416 5,416 — 2,138 2,138 Foreign exchange forward contracts — 907 907 — 15,495 15,495 Totals $ 181,286 $ 396,323 $ 577,609 $ 140,800 $ 252,633 $ 393,433 Liabilities: Interest rate contracts $ — $ — $ — $ — $ 392 $ 392 Foreign exchange forward contracts — 1,120 1,120 — 5,017 5,017 Totals $ — $ 1,120 $ 1,120 $ — $ 5,409 $ 5,409

Derivative Instruments and He26

Derivative Instruments and Hedging Activities (Tables)	3 Months Ended
	Mar. 31, 2018
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Schedule of gains (losses) on derivative instruments	The impact on accumulated other comprehensive loss and earnings from derivative instruments that qualified as cash flow hedges for the three months ended March 31, 2018 and 2017 was as follows (in thousands): Three Months Ended Interest Rate Contracts: 2018 2017 Gain (loss) recognized in accumulated other comprehensive loss, net of tax $ 3,037 $ (855 ) Loss reclassified from accumulated other comprehensive loss to interest expense, net of tax 167 233
Schedule of the fair value of outstanding derivatives	The following tables summarize the fair value of outstanding derivatives (in thousands): March 31, 2018 Asset Derivatives Liability Derivatives Balance Sheet Location Fair Value Balance Sheet Location Fair Value Derivatives designated as hedging instruments: Interest rate contracts Other current assets $ 706 Accrued liabilities $ — Other non-current assets 4,710 Derivatives not designated as hedging instruments: Foreign exchange forward contracts Other current assets 907 Accrued liabilities 1,120 Total fair value of derivative instruments $ 6,323 $ 1,120 December 31, 2017 Asset Derivatives Liability Derivatives Balance Sheet Location Fair Value Balance Sheet Location Fair Value Derivatives designated as hedging instruments: Interest rate contracts Other non-current assets $ 2,138 Accrued liabilities $ 392 Derivatives not designated as hedging instruments: Foreign exchange forward contracts Other current assets 15,495 Accrued liabilities 5,017 Total fair value of derivative instruments $ 17,633 $ 5,409
Schedule of offsetting assets	The following tables summarize the potential effect on our condensed consolidated balance sheets of offsetting our interest rate contracts and foreign exchange forward contracts subject to such provisions (in thousands): March 31, 2018 Gross Amounts of Recognized Assets/ Liabilities Gross Amounts Offset in the Consolidated Balance Sheet Net Amounts of Assets/ Liabilities Presented in the Consolidated Balance Sheet Gross Amounts Not Offset in the Consolidated Balance Sheet Description Derivative Financial Instruments Cash Collateral Received (Pledged) Net Amount Derivative assets $ 2,711 $ — $ 2,711 $ (71 ) $ — $ 2,640 Derivative liabilities (71 ) — (71 ) 71 — — December 31, 2017 Gross Amounts of Recognized Assets/ Liabilities Gross Amounts Offset in the Consolidated Balance Sheet Net Amounts of Assets/ Liabilities Presented in the Consolidated Balance Sheet Gross Amounts Not Offset in the Consolidated Balance Sheet Description Derivative Financial Instruments Cash Collateral Received (Pledged) Net Amount Derivative assets $ 1,639 $ — $ 1,639 $ (875 ) $ — $ 764 Derivative liabilities (875 ) — (875 ) 875 — —
Schedule of offsetting liabilities	The following tables summarize the potential effect on our condensed consolidated balance sheets of offsetting our interest rate contracts and foreign exchange forward contracts subject to such provisions (in thousands): March 31, 2018 Gross Amounts of Recognized Assets/ Liabilities Gross Amounts Offset in the Consolidated Balance Sheet Net Amounts of Assets/ Liabilities Presented in the Consolidated Balance Sheet Gross Amounts Not Offset in the Consolidated Balance Sheet Description Derivative Financial Instruments Cash Collateral Received (Pledged) Net Amount Derivative assets $ 2,711 $ — $ 2,711 $ (71 ) $ — $ 2,640 Derivative liabilities (71 ) — (71 ) 71 — — December 31, 2017 Gross Amounts of Recognized Assets/ Liabilities Gross Amounts Offset in the Consolidated Balance Sheet Net Amounts of Assets/ Liabilities Presented in the Consolidated Balance Sheet Gross Amounts Not Offset in the Consolidated Balance Sheet Description Derivative Financial Instruments Cash Collateral Received (Pledged) Net Amount Derivative assets $ 1,639 $ — $ 1,639 $ (875 ) $ — $ 764 Derivative liabilities (875 ) — (875 ) 875 — —

Inventories (Tables)

Inventories (Tables)	3 Months Ended
	Mar. 31, 2018
Inventory Disclosure [Abstract]
Components of Inventories	Inventories consisted of the following (in thousands): March 31, December 31, Raw materials $ 5,083 $ 3,542 Work in process 21,238 15,692 Finished goods 20,063 24,011 Total inventories $ 46,384 $ 43,245

Goodwill and Intangible Assets

Goodwill and Intangible Assets (Tables)	3 Months Ended
	Mar. 31, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
Gross Carrying Amount of Goodwill	The gross carrying amount of goodwill was as follows (in thousands): Balance at December 31, 2017 $ 947,537 Foreign exchange 12,972 Balance at March 31, 2018 $ 960,509
Gross Carrying Amounts and Net Book Values of Intangible Assets	The gross carrying amounts and net book values of our intangible assets were as follows (in thousands): March 31, 2018 December 31, 2017 Remaining Gross Accumulated Net Book Gross Accumulated Net Book Acquired developed technologies 14.6 $ 3,426,056 $ (625,755 ) $ 2,800,301 $ 3,392,832 $ (562,473 ) $ 2,830,359 Manufacturing contracts — 13,192 (13,192 ) — 12,824 (12,634 ) 190 Trademarks — 2,918 (2,918 ) — 2,910 (2,910 ) — Total finite-lived intangible assets 3,442,166 (641,865 ) 2,800,301 3,408,566 (578,017 ) 2,830,549 Acquired IPR&D assets 152,845 — 152,845 148,578 — 148,578 Total intangible assets $ 3,595,011 $ (641,865 ) $ 2,953,146 $ 3,557,144 $ (578,017 ) $ 2,979,127
Estimated Future Amortization Costs	Based on finite-lived intangible assets recorded as of March 31, 2018 , and assuming the underlying assets will not be impaired and that we will not change the expected lives of the assets, future amortization expenses were estimated as follows (in thousands): Year Ending December 31, Estimated Amortization Expense 2018 (remainder) $ 158,964 2019 211,923 2020 208,917 2021 207,837 2022 207,083 Thereafter 1,805,577 Total $ 2,800,301

Certain Balance Sheet Items (Ta

Certain Balance Sheet Items (Tables)	3 Months Ended
	Mar. 31, 2018
Certain Balance Sheet Items [Abstract]
Property and Equipment	Property, plant and equipment consisted of the following (in thousands): March 31, December 31, Build-to-suit facility $ 52,222 $ 51,721 Land and buildings 46,857 46,729 Leasehold improvements 29,491 28,779 Construction-in-progress 27,820 21,738 Manufacturing equipment and machinery 24,794 23,586 Computer software 19,391 19,969 Computer equipment 12,481 12,814 Furniture and fixtures 6,739 5,947 Subtotal 219,795 211,283 Less accumulated depreciation and amortization (40,875 ) (41,203 ) Property, plant and equipment, net $ 178,920 $ 170,080
Accrued Liabilities	Accrued liabilities consisted of the following (in thousands): March 31, December 31, Rebates and other sales deductions $ 88,878 $ 81,368 Estimated loss contingency 57,000 — Employee compensation and benefits 40,966 54,930 Royalties 7,050 8,058 Selling and marketing accruals 4,546 3,189 Clinical trial accruals 4,053 2,181 Professional fees 3,597 3,213 Inventory-related accruals 3,223 3,002 Sales returns reserve 3,107 3,651 Accrued interest 2,638 7,297 Derivative instrument liabilities 1,120 5,409 Accrued construction-in-progress 838 2,827 Other 23,528 23,654 Total accrued liabilities $ 240,544 $ 198,779

Debt (Tables)

Debt (Tables)	3 Months Ended
	Mar. 31, 2018
Debt Disclosure [Abstract]
Schedule of Long-term Debt	The following table summarizes the carrying amount of our indebtedness (in thousands): March 31, December 31, 2021 Notes $ 575,000 $ 575,000 Unamortized discount and debt issuance costs on 2021 Notes (76,668 ) (81,627 ) 2021 Notes, net 498,332 493,373 2024 Notes 575,000 575,000 Unamortized discount and debt issuance costs on 2024 Notes (153,908 ) (158,680 ) 2024 Notes, net 421,092 416,320 Term loan 662,737 671,345 Total debt 1,582,161 1,581,038 Less current portion 45,117 40,605 Total long-term debt $ 1,537,044 $ 1,540,433

Shareholders' Equity (Tables)

Shareholders' Equity (Tables)	3 Months Ended
	Mar. 31, 2018
Stockholders' Equity Note [Abstract]
Reconciliation of Shareholders' Equity	The following tables present a reconciliation of our beginning and ending balances in shareholders’ equity for the three months ended March 31, 2018 and 2017 (in thousands): Total Shareholders' Equity Shareholders' equity at January 1, 2018 $ 2,713,097 Effect of adoption of new accounting standards (298 ) Issuance of ordinary shares in conjunction with employee equity incentive and purchase plans 10,588 Employee withholding taxes related to share-based awards (14,594 ) Share-based compensation 24,276 Shares repurchased (34,546 ) Other comprehensive income 42,057 Net income 45,991 Shareholders' equity at March 31, 2018 $ 2,786,571 Total Shareholders' Equity Shareholders' equity at January 1, 2017 $ 1,877,339 Issuance of ordinary shares in conjunction with employee equity incentive and purchase plans 5,676 Employee withholding taxes related to share-based awards (14,431 ) Share-based compensation 25,297 Shares repurchased (13,896 ) Other comprehensive income 17,490 Net income 86,511 Shareholders' equity at March 31, 2017 $ 1,983,986
Components of Accumulated Other Comprehensive Loss	The components of accumulated other comprehensive loss as of March 31, 2018 and December 31, 2017 were as follows (in thousands): Net Unrealized Foreign Total Balance at December 31, 2017 $ 1,482 $ (142,360 ) $ (140,878 ) Effect of adoption of ASU No. 2017-12 53 — 53 Balance at January 1, 2018 1,535 (142,360 ) (140,825 ) Other comprehensive income before reclassifications 3,037 38,853 41,890 Amounts reclassified from accumulated other comprehensive loss 167 — 167 Other comprehensive income, net 3,204 38,853 42,057 Balance at March 31, 2018 $ 4,739 $ (103,507 ) $ (98,768 )

Net Income per Ordinary Share (

Net Income per Ordinary Share (Tables)	3 Months Ended
	Mar. 31, 2018
Earnings Per Share [Abstract]
Basic and Diluted Net Income per Ordinary Share Computation	Basic and diluted net income per ordinary share were computed as follows (in thousands, except per share amounts): Three Months Ended 2018 2017 Numerator: Net income $ 45,991 $ 86,511 Denominator: Weighted-average ordinary shares used in per share calculations - basic 59,928 59,880 Dilutive effect of employee equity incentive and purchase plans 1,250 1,298 Weighted-average ordinary shares used in per share calculations - diluted 61,178 61,178 Net income per ordinary share: Basic $ 0.77 $ 1.44 Diluted $ 0.75 $ 1.41
Weighted-Average Ordinary Shares Excluded from Computation of Diluted Net Income per Share	The following table represents the weighted-average ordinary shares that were excluded from the calculation of diluted net income per ordinary share for the periods presented because including them would have an anti-dilutive effect (in thousands): Three Months Ended 2018 2017 Exchangeable Senior Notes 5,504 2,878 Options to purchase ordinary shares and RSUs 3,279 3,406 Ordinary shares under ESPP 26 —

Revenues (Tables)

Revenues (Tables)	3 Months Ended
	Mar. 31, 2018
Revenue from Contract with Customer [Abstract]
Summary of disaggregation of revenue	The following table presents a summary of total revenues (in thousands): Three Months Ended 2018 2017 Xyrem $ 316,777 $ 272,326 Erwinaze/Erwinase 50,627 51,388 Defitelio/defibrotide 35,061 35,900 Vyxeos 26,228 — Prialt ® (ziconotide) intrathecal infusion 6,126 7,717 Other 6,028 6,347 Product sales, net 440,847 373,678 Royalties and contract revenues 3,766 2,375 Total revenues $ 444,613 $ 376,053 The following table presents a summary of total revenues attributed to geographic sources (in thousands): Three Months Ended 2018 2017 United States $ 405,687 $ 339,183 Europe 28,331 31,352 All other 10,595 5,518 Total revenues $ 444,613 $ 376,053
Summary of Revenues from Customers Representing More Than 10% of Total Revenues	The following table presents a summary of the percentage of total revenues from customers that represented more than 10% of our total revenues: Three Months Ended 2018 2017 Express Scripts 71 % 72 % McKesson 20 % 17 %
Summary of a reconciliation in contract liabilities from contracts with customer	The following table presents a reconciliation of our beginning and ending balances in contract liabilities from contracts with customers for the three months ended March 31, 2018 (in thousands): Contract Liabilities Balance as of December 31, 2017 $ 24,733 Effect of adoption of ASU 2014-09 (2,240 ) Amount recognized within royalties and contract revenues (1,875 ) Balance as of March 31, 2018 $ 20,618

Share-Based Compensation (Table

Share-Based Compensation (Tables)	3 Months Ended
	Mar. 31, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Share-Based Compensation Expense Related to Share Options, RSUs and Grants Under ESPP	Share-based compensation expense related to share options, RSUs and grants under our ESPP was as follows (in thousands): Three Months Ended 2018 2017 Selling, general and administrative $ 18,234 $ 19,805 Research and development 4,375 4,142 Cost of product sales 1,694 1,246 Total share-based compensation expense, pre-tax 24,303 25,193 Income tax benefit from share-based compensation expense (3,668 ) (7,624 ) Total share-based compensation expense, net of tax $ 20,635 $ 17,569
Weighted-Average Assumptions Used in Black-Scholes Option Pricing Model which was Used to Estimate Grant Date Fair Value per Share	The table below shows the number of shares underlying options granted to purchase our ordinary shares, the weighted-average assumptions used in the Black-Scholes option pricing model and the resulting weighted-average grant date fair value of share options granted: Three Months Ended 2018 2017 Shares underlying options granted (in thousands) 1,152 1,171 Grant date fair value $ 46.08 $ 42.19 Black-Scholes option pricing model assumption information: Volatility 35 % 35 % Expected term (years) 4.5 4.3 Range of risk-free rates 2.2-2.5% 1.7-1.8% Expected dividend yield — % — %
Schedule of Restricted Stock Unit activity	The table below shows the number of RSUs granted covering an equal number of our ordinary shares and the weighted-average grant date fair value of RSUs granted: Three Months Ended 2018 2017 RSUs granted (in thousands) 461 468 Grant date fair value $ 140.60 $ 135.46

The Company and Summary of Si35

The Company and Summary of Significant Accounting Policies - Basis of Presentation Additional Information (Details)	3 Months Ended
	Mar. 31, 2018Segment
Accounting Policies [Abstract]
Number of operating business segment	1

The Company and Summary of Si36

The Company and Summary of Significant Accounting Policies - Cumulative Effect on the Consolidated Balance Sheet (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Jan. 01, 2018	Dec. 31, 2017
ASSETS
Deferred tax assets, net	$ 38,103	$ 35,154	$ 34,559
Liabilities:
Deferred revenue	6,977	7,498	8,618
Deferred revenue, non-current	13,641	14,995	16,115
Deferred tax liabilities, net	382,072	386,605	383,472
Shareholders’ equity:
Accumulated other comprehensive loss	(98,768)	(140,825)	(140,878)
Retained earnings	$ 929,050	917,605	917,956
Previously Reported
ASSETS
Deferred tax assets, net			34,559
Liabilities:
Deferred revenue			8,618
Deferred revenue, non-current			16,115
Deferred tax liabilities, net			383,472
Shareholders’ equity:
Accumulated other comprehensive loss			(140,878)
Retained earnings			$ 917,956
Transition Adjustments
ASSETS
Deferred tax assets, net		595
Liabilities:
Deferred revenue		(1,120)
Deferred revenue, non-current		(1,120)
Deferred tax liabilities, net		3,133
Shareholders’ equity:
Accumulated other comprehensive loss		53
Retained earnings		$ (351)

The Company and Summary of Si37

The Company and Summary of Significant Accounting Policies - Concentrations of Risk Additional Information (Details)	3 Months Ended
	Mar. 31, 2018USD ($)Customer	Dec. 31, 2017USD ($)
Concentration Risk [Line Items]
Number of customers with significant accounts receivable | Customer	5
Customer concentration risk | Gross accounts receivable
Concentration Risk [Line Items]
Percentage of gross accounts receivable (as a percent)	93.00%
Customer concentration risk | Gross accounts receivable | Express Scripts
Concentration Risk [Line Items]
Percentage of gross accounts receivable (as a percent)	72.00%
Customer concentration risk | Gross accounts receivable | McKesson
Concentration Risk [Line Items]
Percentage of gross accounts receivable (as a percent)	19.00%
Foreign exchange forward contracts | Derivatives not designated as hedging instruments
Concentration Risk [Line Items]
Notional amount	$ 186,500,000	$ 98,700,000
Net fair value	(200,000)
Interest rate contracts | Derivatives designated as hedging instruments
Concentration Risk [Line Items]
Notional amount	300,000,000	$ 300,000,000
Net fair value	$ 5,400,000

The Company and Summary of Si38

The Company and Summary of Significant Accounting Policies - Recent Accounting Pronouncements Additional Information (Details) $ in Millions	Mar. 31, 2018USD ($)
Building | Palo Alto And Dublin
Lessee, Lease, Description [Line Items]
Future minimum lease payments	$ 213.9

Cash and Available-for-Sale S39

Cash and Available-for-Sale Securities - Summary of Cash and Cash Equivalents (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017	Mar. 31, 2017	Dec. 31, 2016
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	$ 708,169	$ 601,035
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Estimated Fair Value	708,169	601,035
Cash and cash equivalents	453,169	386,035	$ 346,995	$ 365,963
Investments	255,000	215,000
Cash
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	136,883	225,235
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Estimated Fair Value	136,883	225,235
Cash and cash equivalents	136,883	225,235
Investments	0	0
Time deposits
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	390,000	235,000
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Estimated Fair Value	390,000	235,000
Cash and cash equivalents	135,000	20,000
Investments	255,000	215,000
Money market funds
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	181,286	140,800
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Estimated Fair Value	181,286	140,800
Cash and cash equivalents	181,286	140,800
Investments	$ 0	$ 0

Fair Value Measurement - Assets

Fair Value Measurement - Assets and Liabilities Measured at Fair Value on Recurring Basis (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Available-for-sale securities:
Available-for-sale securities	$ 708,169	$ 601,035
Time deposits
Available-for-sale securities:
Available-for-sale securities	390,000	235,000
Money market funds
Available-for-sale securities:
Available-for-sale securities	181,286	140,800
Recurring | Total Estimated Fair Value
Available-for-sale securities:
Totals	577,609	393,433
Liabilities:
Totals	1,120	5,409
Recurring | Total Estimated Fair Value | Interest rate contracts
Available-for-sale securities:
Derivative asset	5,416	2,138
Liabilities:
Derivative liabilities	0	392
Recurring | Total Estimated Fair Value | Foreign exchange forward contracts
Available-for-sale securities:
Derivative asset	907	15,495
Liabilities:
Derivative liabilities	1,120	5,017
Recurring | Total Estimated Fair Value | Time deposits
Available-for-sale securities:
Available-for-sale securities	390,000	235,000
Recurring | Total Estimated Fair Value | Money market funds
Available-for-sale securities:
Available-for-sale securities	181,286	140,800
Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1)
Available-for-sale securities:
Totals	181,286	140,800
Liabilities:
Totals	0	0
Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | Interest rate contracts
Available-for-sale securities:
Derivative asset	0	0
Liabilities:
Derivative liabilities	0	0
Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | Foreign exchange forward contracts
Available-for-sale securities:
Derivative asset	0	0
Liabilities:
Derivative liabilities	0	0
Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | Time deposits
Available-for-sale securities:
Available-for-sale securities	0	0
Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | Money market funds
Available-for-sale securities:
Available-for-sale securities	181,286	140,800
Recurring | Significant Other Observable Inputs (Level 2)
Available-for-sale securities:
Totals	396,323	252,633
Liabilities:
Totals	1,120	5,409
Recurring | Significant Other Observable Inputs (Level 2) | Interest rate contracts
Available-for-sale securities:
Derivative asset	5,416	2,138
Liabilities:
Derivative liabilities	0	392
Recurring | Significant Other Observable Inputs (Level 2) | Foreign exchange forward contracts
Available-for-sale securities:
Derivative asset	907	15,495
Liabilities:
Derivative liabilities	1,120	5,017
Recurring | Significant Other Observable Inputs (Level 2) | Time deposits
Available-for-sale securities:
Available-for-sale securities	390,000	235,000
Recurring | Significant Other Observable Inputs (Level 2) | Money market funds
Available-for-sale securities:
Available-for-sale securities	$ 0	$ 0

Fair Value Measurement - Additi

Fair Value Measurement - Additional Information (Details) - Convertible Debt - USD ($) $ in Millions	Mar. 31, 2018	Sep. 30, 2017	Aug. 31, 2014
2021 Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Interest rate (as a percent)			1.875%
Fair value of exchangeable senior notes	$ 602
2024 Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Interest rate (as a percent)		1.50%
Fair value of exchangeable senior notes	$ 561

Derivative Instruments and He42

Derivative Instruments and Hedging Activities - Additional Information (Details) - USD ($)	3 Months Ended
	Mar. 31, 2018	Dec. 31, 2017
Derivative [Line Items]
Gains recognized in AOCI to be reclassified over the next 12 months	$ 600,000
Interest rate contracts | Derivatives designated as hedging instruments
Derivative [Line Items]
Notional amount	$ 300,000,000	$ 300,000,000
Interest rate contracts | Derivatives not designated as hedging instruments
Derivative [Line Items]
Fixed interest rate	1.895%
Foreign exchange forward contracts | Derivatives not designated as hedging instruments
Derivative [Line Items]
Notional amount	$ 186,500,000	$ 98,700,000
Gain recognized in other income and expense	$ 3,800,000
Maximum | Foreign exchange forward contracts | Derivatives not designated as hedging instruments
Derivative [Line Items]
Contract term	12 months

Derivative Instruments and He43

Derivative Instruments and Hedging Activities - Gains on Derivative Instruments (Details) - Interest rate contracts - Cash Flow Hedges - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) recognized in accumulated other comprehensive loss, net of tax	$ 3,037	$ (855)
Loss reclassified from accumulated other comprehensive loss to interest expense, net of tax	$ 167	$ 233

Derivative Instruments and He44

Derivative Instruments and Hedging Activities - Fair Value of Outstanding Derivatives (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Derivatives, Fair Value [Line Items]
Asset Derivatives	$ 6,323	$ 17,633
Liability Derivatives	1,120	5,409
Derivatives designated as hedging instruments | Interest rate contracts | Other current assets
Derivatives, Fair Value [Line Items]
Asset Derivatives	706
Derivatives designated as hedging instruments | Interest rate contracts | Other non-current assets
Derivatives, Fair Value [Line Items]
Asset Derivatives	4,710	2,138
Derivatives designated as hedging instruments | Interest rate contracts | Accrued liabilities
Derivatives, Fair Value [Line Items]
Liability Derivatives	0	392
Derivatives not designated as hedging instruments | Foreign exchange forward contracts | Other current assets
Derivatives, Fair Value [Line Items]
Asset Derivatives	907	15,495
Derivatives not designated as hedging instruments | Foreign exchange forward contracts | Accrued liabilities
Derivatives, Fair Value [Line Items]
Liability Derivatives	$ 1,120	$ 5,017

Derivative Instruments and He45

Derivative Instruments and Hedging Activities - Offsetting Assets and Liabilities (Details) - Pro Forma [Member] - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Derivative assets
Gross Amounts of Recognized Assets/ Liabilities	$ 2,711	$ 1,639
Gross Amounts Offset in the Consolidated Balance Sheet	0	0
Net Amounts of Assets/ Liabilities Presented in the Consolidated Balance Sheet	2,711	1,639
Gross Amounts Not Offset in the Consolidated Balance Sheet
Derivative Financial Instruments	(71)	(875)
Cash Collateral Received (Pledged)	0	0
Net Amount	2,640	764
Derivative liabilities
Gross Amounts of Recognized Assets/ Liabilities	(71)	(875)
Gross Amounts Offset in the Consolidated Balance Sheet	0	0
Net Amounts of Assets/ Liabilities Presented in the Consolidated Balance Sheet	(71)	(875)
Gross Amounts Not Offset in the Consolidated Balance Sheet
Derivative Financial Instruments	71	875
Cash Collateral Received (Pledged)	0	0
Net Amount	$ 0	$ 0

Inventories - Components of Inv

Inventories - Components of Inventories (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Inventory Disclosure [Abstract]
Raw materials	$ 5,083	$ 3,542
Work in process	21,238	15,692
Finished goods	20,063	24,011
Total inventories	$ 46,384	$ 43,245

Goodwill and Intangible Asset47

Goodwill and Intangible Assets - Goodwill Activity (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2018USD ($)
Goodwill [Roll Forward]
Goodwill, beginning of period	$ 947,537
Foreign exchange	12,972
Goodwill, end of period	$ 960,509

Goodwill and Intangible Asset48

Goodwill and Intangible Assets - Gross Carrying Amounts and Net Book Values of Intangible Assets (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Dec. 31, 2017
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 3,442,166	$ 3,408,566
Accumulated Amortization	(641,865)	(578,017)
Total	2,800,301	2,830,549
Indefinite-lived Intangible Assets [Line Items]
Gross Carrying Amount - Total Intangible Assets	3,595,011	3,557,144
Net Book Value - Total Intangible Assets	2,953,146	2,979,127
Acquired IPR&D assets
Indefinite-lived Intangible Assets [Line Items]
In-process research and development	$ 152,845	148,578
Acquired developed technologies
Finite-Lived Intangible Assets [Line Items]
Remaining Weighted-Average Useful Life (in years)	14 years 7 months
Gross Carrying Amount	$ 3,426,056	3,392,832
Accumulated Amortization	(625,755)	(562,473)
Total	$ 2,800,301	2,830,359
Manufacturing contracts
Finite-Lived Intangible Assets [Line Items]
Remaining Weighted-Average Useful Life (in years)	0 years
Gross Carrying Amount	$ 13,192	12,824
Accumulated Amortization	(13,192)	(12,634)
Total	$ 0	190
Trademarks
Finite-Lived Intangible Assets [Line Items]
Remaining Weighted-Average Useful Life (in years)	0 years
Gross Carrying Amount	$ 2,918	2,910
Accumulated Amortization	(2,918)	(2,910)
Total	$ 0	$ 0

Goodwill and Intangible Asset49

Goodwill and Intangible Assets - Estimated Future Amortization Costs (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Estimated Amortization Expense
2018 (remainder)	$ 158,964
2,019	211,923
2,020	208,917
2,021	207,837
2,022	207,083
Thereafter	1,805,577
Total	$ 2,800,301	$ 2,830,549

Certain Balance Sheet Items - P

Certain Balance Sheet Items - Property and Equipment (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 219,795	$ 211,283
Less accumulated depreciation and amortization	(40,875)	(41,203)
Property, plant and equipment, net	178,920	170,080
Build-to-suit facility
Property, Plant and Equipment [Line Items]
Property and equipment, gross	52,222	51,721
Land and buildings
Property, Plant and Equipment [Line Items]
Property and equipment, gross	46,857	46,729
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property and equipment, gross	29,491	28,779
Construction-in-progress
Property, Plant and Equipment [Line Items]
Property and equipment, gross	27,820	21,738
Manufacturing equipment and machinery
Property, Plant and Equipment [Line Items]
Property and equipment, gross	24,794	23,586
Computer software
Property, Plant and Equipment [Line Items]
Property and equipment, gross	19,391	19,969
Computer equipment
Property, Plant and Equipment [Line Items]
Property and equipment, gross	12,481	12,814
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 6,739	$ 5,947

Certain Balance Sheet Items - A

Certain Balance Sheet Items - Accrued Liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Certain Balance Sheet Items [Abstract]
Rebates and other sales deductions	$ 88,878	$ 81,368
Estimated loss contingency	57,000	0
Employee compensation and benefits	40,966	54,930
Royalties	7,050	8,058
Selling and marketing accruals	4,546	3,189
Clinical trial accruals	4,053	2,181
Professional fees	3,597	3,213
Inventory-related accruals	3,223	3,002
Sales returns reserve	3,107	3,651
Accrued interest	2,638	7,297
Derivative instrument liabilities	1,120	5,409
Accrued construction-in-progress	838	2,827
Other	23,528	23,654
Total accrued liabilities	$ 240,544	$ 198,779

Debt - Schedule of Long-term De

Debt - Schedule of Long-term Debt (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Debt Instrument [Line Items]
Total debt	$ 1,582,161	$ 1,581,038
Less current portion	45,117	40,605
Total long-term debt	1,537,044	1,540,433
Convertible Debt | 2021 Notes
Debt Instrument [Line Items]
Long term debt outstanding	575,000	575,000
Unamortized discount and debt issuance costs	(76,668)	(81,627)
Total debt	498,332	493,373
Convertible Debt | 2024 Notes
Debt Instrument [Line Items]
Long term debt outstanding	575,000	575,000
Unamortized discount and debt issuance costs	(153,908)	(158,680)
Total debt	421,092	416,320
Term Loan
Debt Instrument [Line Items]
Total debt	$ 662,737	$ 671,345

Debt - Additional Information (

Debt - Additional Information (Details) - Convertible Debt $ in Millions	Mar. 31, 2018USD ($)
Debt Instrument [Line Items]
Percentage of ownership (as a percent)	100.00%
2021 Notes
Debt Instrument [Line Items]
Carrying value of the equity component	$ 126.9
2024 Notes
Debt Instrument [Line Items]
Carrying value of the equity component	$ 149.8

Commitments and Contingencies -

Commitments and Contingencies - Lease and Other Commitments (Details) $ in Thousands	1 Months Ended
	Sep. 30, 2017renewal_term	Jan. 31, 2015renewal_term	Mar. 31, 2018USD ($)	Dec. 31, 2017USD ($)
Operating Leased Assets [Line Items]
Other non-current liabilities			$ 192,181	$ 176,608
Noncancelable purchase commitments, due within one year			74,400
Building | Palo Alto
Operating Leased Assets [Line Items]
Operating lease, term	12 years	12 years
Financing obligation			64,400
Building | Palo Alto | Property and Equipment, Net
Operating Leased Assets [Line Items]
Construction-in-progress			24,800
Building | Palo Alto | Other Non-Current Liabilities
Operating Leased Assets [Line Items]
Other non-current liabilities			$ 24,800
Building | Palo Alto | Lease Agreements
Operating Leased Assets [Line Items]
Number of renewal option terms | renewal_term	2	2
Operating lease, extended term option	5 years	5 years

Commitments and Contingencies55

Commitments and Contingencies - Legal Proceedings and Other Contingencies (Details) $ in Millions	1 Months Ended						3 Months Ended	12 Months Ended
	Apr. 30, 2018USD ($)	Mar. 31, 2017claim_under_petition	Jul. 31, 2016patent	Mar. 31, 2016claim_under_petition	Apr. 30, 2015litigation_case	Jan. 31, 2015patent	Mar. 31, 2018USD ($)	Dec. 31, 2017lawsuit
Xyrem
Commitments and Contingencies Disclosure [Line Items]
Number of claims settled | lawsuit								4
Pending Litigation | Xyrem
Commitments and Contingencies Disclosure [Line Items]
Number of patents named in review petitions | patent						6
Number of Xyrem REMS patents | patent						7
Number of patents deemed unenforceable by PTAB | patent			6
Number of petition claims under patent review awaiting decision				3
Number of petition claims PTAB denied				25
Number of petition claims under patent review				28
Number of petition claims under patent review deemed unpatentable		3
Xyrem ANDA Matters | Pending Litigation
Commitments and Contingencies Disclosure [Line Items]
Number of litigation cases after consolidation | litigation_case					1
DOJ Investigation
Commitments and Contingencies Disclosure [Line Items]
Estimated loss contingency | $							$ 57
Subsequent Event | DOJ Investigation
Commitments and Contingencies Disclosure [Line Items]
Proposed settlement amount | $	$ 57

Shareholders' Equity - Equity C

Shareholders' Equity - Equity Components (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	$ 2,713,097	$ 1,877,339
Effect of adoption of new accounting standards			$ (298)
Issuance of ordinary shares in conjunction with employee equity incentive and purchase plans	10,588	5,676
Employee withholding taxes related to share-based awards	(14,594)	(14,431)
Share-based compensation	24,276	25,297
Shares repurchased	(34,546)	(13,896)
Other comprehensive income	42,057	17,490
Net income	45,991	86,511
Ending balance	$ 2,786,571	$ 1,983,986

Shareholders' Equity - Share Re

Shareholders' Equity - Share Repurchase Programs (Details) - USD ($) $ / shares in Units, shares in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Nov. 30, 2016
Stock Activity [Line Items]
Shares repurchased	$ 34,546,000	$ 13,896,000
Ordinary Options
Stock Activity [Line Items]
Shares repurchased	$ 34,500,000
Shares repurchased (in shares)	0.2
Average price of shares repurchased (in dollars per share)	$ 145.34
Ordinary Options | November 2016 Share Repurchase Program
Stock Activity [Line Items]
Total amount authorized for repurchase of shares under share repurchase program			$ 300,000,000
Remaining amount authorized for repurchase of shares	$ 148,200,000

Shareholders' Equity - Componen

Shareholders' Equity - Component of Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Increase (Decrease) in Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	$ 2,713,097	$ 1,877,339
Effect of adoption of new accounting standards			$ (298)
Other comprehensive income before reclassifications	41,890
Amounts reclassified from accumulated other comprehensive loss	167
Other comprehensive income	42,057	17,490
Ending balance	2,786,571	$ 1,983,986
Net Unrealized Gain From Hedging Activities
Increase (Decrease) in Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	1,535
Other comprehensive income before reclassifications	3,037
Amounts reclassified from accumulated other comprehensive loss	167
Other comprehensive income	3,204
Ending balance	4,739
Net Unrealized Gain From Hedging Activities | ASU No. 2017-12
Increase (Decrease) in Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Effect of adoption of new accounting standards			53
Foreign Currency Translation Adjustments
Increase (Decrease) in Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	(142,360)
Other comprehensive income before reclassifications	38,853
Amounts reclassified from accumulated other comprehensive loss	0
Other comprehensive income	38,853
Ending balance	(103,507)
Foreign Currency Translation Adjustments | ASU No. 2017-12
Increase (Decrease) in Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Effect of adoption of new accounting standards			0
Total Accumulated Other Comprehensive Loss
Increase (Decrease) in Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	(140,825)
Ending balance	(98,768)
Total Accumulated Other Comprehensive Loss | ASU No. 2017-12
Increase (Decrease) in Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Effect of adoption of new accounting standards			$ 53
Previously Reported | Net Unrealized Gain From Hedging Activities
Increase (Decrease) in Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	1,482
Previously Reported | Foreign Currency Translation Adjustments
Increase (Decrease) in Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	(142,360)
Previously Reported | Total Accumulated Other Comprehensive Loss
Increase (Decrease) in Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	$ (140,878)

Net Income per Ordinary Share -

Net Income per Ordinary Share - Basic and Diluted Net Income (Loss) per Common Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Numerator:
Net income	$ 45,991	$ 86,511
Denominator:
Weighted-average ordinary shares used in per share calculation - basic (in shares)	59,928	59,880
Dilutive effect of employee equity incentive and purchase plans (in shares)	1,250	1,298
Weighted-average ordinary shares used in per share calculation - diluted (in shares)	61,178	61,178
Net income per ordinary share:
Basic (in dollars per share)	$ 0.77	$ 1.44
Diluted (in dollars per share)	$ 0.75	$ 1.41

Net Income per Ordinary Share60

Net Income per Ordinary Share - Weighted-Average Ordinary Shares Excluded from Computation of Diluted Net Income per Share (Details) - shares shares in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Exchangeable Senior Notes
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Ordinary shares (in shares)	5,504	2,878
Options to purchase ordinary shares and RSUs
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Ordinary shares (in shares)	3,279	3,406
Ordinary shares under ESPP
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Ordinary shares (in shares)	26	0

Revenues - Summary of Disaggreg

Revenues - Summary of Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Disaggregation of Revenue [Line Items]
Total revenues	$ 444,613	$ 376,053
United States
Disaggregation of Revenue [Line Items]
Total revenues	405,687	339,183
Europe
Disaggregation of Revenue [Line Items]
Total revenues	28,331	31,352
All other
Disaggregation of Revenue [Line Items]
Total revenues	10,595	5,518
Product sales, net
Disaggregation of Revenue [Line Items]
Total revenues	440,847	373,678
Xyrem
Disaggregation of Revenue [Line Items]
Total revenues	316,777	272,326
Erwinaze/Erwinase
Disaggregation of Revenue [Line Items]
Total revenues	50,627	51,388
Defitelio/defibrotide
Disaggregation of Revenue [Line Items]
Total revenues	35,061	35,900
Vyxeos
Disaggregation of Revenue [Line Items]
Total revenues	26,228	0
Prialt® (ziconotide) intrathecal infusion
Disaggregation of Revenue [Line Items]
Total revenues	6,126	7,717
Other
Disaggregation of Revenue [Line Items]
Total revenues	6,028	6,347
Royalties and contract revenues
Disaggregation of Revenue [Line Items]
Total revenues	$ 3,766	$ 2,375

Revenues - Summary of the Perce

Revenues - Summary of the Percentage of Total Revenues from Customers (Details) - Total Revenues - Customer concentration risk	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Express Scripts
Concentration Risk [Line Items]
Percentage of total revenues (as a percent)	71.00%	72.00%
McKesson
Concentration Risk [Line Items]
Percentage of total revenues (as a percent)	20.00%	17.00%

Revenues - Additional Informati

Revenues - Additional Information (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2018USD ($)agreement
Summary Of Deferred Revenue [Line Items]
Contract revenue recognized	$ 1,875
Nippon Shinyaku
Summary Of Deferred Revenue [Line Items]
Number of license, development and commercialization agreements | agreement	2
Contract revenue recognized	$ 1,900
Expected timing of performance for research and development obligation	4 years

Revenues - Summary of Contract

Revenues - Summary of Contract Liabilities (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2018USD ($)
Change In Contract With Customer, Liability [Roll Forward]
Beginning balance	$ 24,733
Effect of adoption of ASU 2014-09	(2,240)
Amount recognized within royalties and contract revenues	(1,875)
Ending balance	$ 20,618

Share-Based Compensation - Expe

Share-Based Compensation - Expense (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total share-based compensation expense, pre-tax	$ 24,303	$ 25,193
Income tax benefit from share-based compensation expense	(3,668)	(7,624)
Total share-based compensation expense, net of tax	20,635	17,569
Selling, general and administrative
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total share-based compensation expense, pre-tax	18,234	19,805
Research and development
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total share-based compensation expense, pre-tax	4,375	4,142
Cost of product sales
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total share-based compensation expense, pre-tax	$ 1,694	$ 1,246

Share-Based Compensation - Weig

Share-Based Compensation - Weighted-Average Assumptions and Resulting Grant Date Fair Value (Details) - Employee Stock Option - $ / shares shares in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Schedule of Weighted Average Assumptions for Fair Values of Stock Options[Line Items]
Shares underlying options granted (in shares)	1,152	1,171
Weighted-average grant date fair value (in dollars per share)	$ 46.08	$ 42.19
Weighted-average volatility (as a percent)	35.00%	35.00%
Weighted-average expected term	4 years 6 months	4 years 3 months
Range of risk-free rates, minimum (as a percent)	2.20%	1.70%
Range of risk-free rates, maximum (as a percent)	2.50%	1.80%
Expected dividend yield (as a percent)	0.00%	0.00%

Share-Based Compensation - Rest

Share-Based Compensation - Restricted Units (Details) - Restricted Stock Units (RSUs) - $ / shares shares in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
RSUs granted (in shares)	461	468
Grant date fair value (in dollars per share)	$ 140.60	$ 135.46

Share-Based Compensation - Addi

Share-Based Compensation - Additional Information (Details) $ in Millions	3 Months Ended
	Mar. 31, 2018USD ($)
Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	4 years
Unrecognized compensation cost related to unvested stock option and RSUs	$ 121.5
Weighted-average period expected to be recognized	3 years
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation cost related to unvested stock option and RSUs	$ 101.6
Weighted-average period expected to be recognized	2 years 11 months

Income Taxes - Additional Infor

Income Taxes - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Income Taxes [Line Items]
Income tax provision	$ 19,146	$ 29,160
Effective income tax rate (as a percent)	29.20%	25.20%
Ireland
Income Taxes [Line Items]
Effective statutory income tax rate (as a percent)	12.50%
France
Income Taxes [Line Items]
Proposed additional tax including interest and penalties	$ 47,000

Subsequent Event - Additional I

Subsequent Event - Additional Information (Details) $ in Millions	Apr. 30, 2018USD ($)
Subsequent Event | Forecast
Subsequent Event [Line Items]
Consideration for the priority review voucher	$ 110